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FINAL SCIENCE MEMO

APP202697 – Para-Ken 250 HerbicideSubstance database ID - 48033

April 2016

Project team:

Application advisor: Trudy Geoghegan

Toxicologist: Stuart Creton

Ecotoxicologist: Miguel Santos

Peer-reviewer: Cora Drijver (consultant for the ecotox); Jeane Nicolas (tox)

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1. Executive summary1.1. Background and justification for a Cat B standard pathway

1.1.1 Para-Ken 250 Herbicide is a soluble concentrate containing paraquat dichloride as the active

ingredient, plus other components. It is intended for use as an herbicide for the control of weeds in

Lucerne, Clover seed crops, Forestry, Industrial site, Streets and for Barley grass control.

1.1.2 Para-Ken 250 Herbicide was originally submitted as a Rapid application (APP202591). However it was

declined under this pathway due to international concerns regarding the safety of paraquat for

human health and the environment. Paraquat is banned in the EU and has been either banned or

severely restricted in a number of other countries.

Human health

1.1.3 Para-Ken 250 Herbicide is proposed to be used at a similar application rate to other approved

substances containing paraquat dichloride. However, due to international concerns regarding the

safety of paraquat a quantitative human health risk assessment was undertaken.

Ecotox

1.1.4 Para-Ken 250 Herbicide contains paraquat dichloride and is proposed to be used at a similar

application rate to other approved substances containing paraquat dichloride. However, due to

international concerns regarding the safety of paraquat a quantitative environmental risk assessment

was undertaken.

1.2. Key points

1.2.1 The applicant classified Para-Ken 250 Herbicide as follows: 6.1B (O), 6.1B (D), 6.1A (Inh), 6.3A, 6.4A,

6.9A, 9.1A, 9.3A, 9.4B. The staff classified Para-Ken 250 Herbicide as follows: 6.1C (O), 6.1B (D), 6.1A (I), 6.3A, 6.4A, 9.1A, 9.3A, 9.4B. The difference in the acute oral toxicity classification appears to

be based on a different interpretation of mixture rules by the applicant.

1.2.2 The applicant provided ecotox studies with a formulation containing 20% paraquat dichloride. The

results with the formulation were used for the risk assessment when considered acceptable.

1.2.3 Predicted exposures of operators during mixing, loading and application of Para-Ken 250 Herbicide

are greater than the AOEL for paraquat, even with the use of full PPE including a respirator.

1.2.4 Based on the use pattern re-entry worker exposure to Para-Ken 250 Herbicide is likely to be minimal

and therefore no quantitative re-entry worker exposure assessment has been performed.

1.2.5 Predicted exposures of a bystander 8 metres away from the edge of an application area are greater

than the acceptable levels for both active ingredients. If spraying of Para-Ken 250 Herbicide were

limited to use of coarse droplets, minimum buffer zones of 16 or 30 metres from sensitive areas would

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be required for low boom or high boom application, respectively, in order to reduce exposures to the

AOEL.

1.2.6 Predicted exposures for children playing directly on a treated area (such as children playing on street

verges) are also substantially higher than the AOEL.

1.2.7 Staff consider that the approval of Para-Ken 250 Herbicide as broadcast spray to clover, Lucerne,

forestry and barley grass control should be declined due to the unacceptable risks posed to aquatic

organisms (algae) and birds.

1.2.8 Staff consider that the application of Para-Ken 250 Herbicide as spot treatment (using knapsack in

non-wide dispersive manner) in non-crop situations such as in streets, industrial sites the risks can be

considered below the level of concern in terms of risks to the environment. However, the staff

recommended that the application using knapsack should be carried out using nozzles equipped to

release coarse droplets and thus preventing spray drift.

1.2.9 Although the risks for the environment could be managed by limiting use of Para-Ken 250 Herbicide to

spot treatment, the human health risk assessment indicates that there would still be unacceptable

risks for operators applying the substance by knapsack and potentially for children playing on treated

areas such as street verges. Therefore it is proposed that the application should be declined.

1.2.10Based on the concerns identified it is proposed that grounds should be sought to reassess Paraquat

and the formulations containing it that are currently approved under HSNO.

1.3. Regulatory status

Table 1 Active ingredient regulatory status

Active ingredient name Regulatory history in New Zealand

International regulatory history

(Australia, Canada, Europe, Japan, USA)

Paraquat dichloride Approved in NZ Approved in Australia, USA and Canada.

Not approved as a pesticide active in Europe. Banned or restricted in a number of other jurisdictions.

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1.4. Use pattern

Table 2 Substance use pattern

Substance categoryWide Dispersive use

Concentration Application rate(s) Remarks

HerbicideYes

No 250 g/L

See GAP Table

April 2016

Table 3 GAP table

Crop and/or

situation

(a)

Product code

FGorI

(b)

Pests orGroup of pests

controlled

(c)

Formulation Application Application rate per treatmentPHI

(days)

(l)

Remarks:

(m)Type

(d-f)

Conc.of as

(i)

methodkind

(f-h)

growthstage & season

(j)

number

min max(k)

interval between

applications (min)

kg as/hL

min max

water L/ha

min max

kg as/ha

min max

Clover seeds F

Grasses, BroadLeaf Weeds SL 250 g/L

High volume

broadcast

2 weeks before

closing clover

crop for seed.

1-2 28 days 0.1-0.16 250-300 0.3-0.4

Fence lines,

Stock yards,

Street verges,

Streets and

Industrial sites

FGrasses, BroadLeaf Weeds SL 250 g/L

High volume

broadcast, Handgun, Knapsack

All stages and

growth seasonsbut more

predominately in thespring/

summer/autumn period

1-4 28 days 0.1-0.3500-1000 1.0-1.5

Crop and/or

situation

(a)

Product code

FGorI

(b)

Pests orGroup of pests

controlled

(c)

Formulation Application Application rate per treatmentPHI

(days)

(l)

Remarks:

(m)Type

(d-f)

Conc.of as

(i)

methodkind

(f-h)

growthstage & season

(j)

number

min max(k)

interval between

applications (min)

kg as/hL

min max

water L/ha

min max

kg as/ha

min max

Forestry FGrasses, BroadLeaf Weeds SL 250 g/L

High volume

broadcast

All stages in

spring/summer/autumn season

1-2 28 days 0.333-0.5 200-300 1

Lucerne FGrasses,Annual BroadLeaf Weeds

SL 250 g/L

High volume

broadcast

Winter while

Lucerne is dormant

1-2 28 days0.133-

0.240250-300 0.4-0.6

Non selective weed control

F

Barley grasses

SL 250 g/L Handgun

During theactive growth

phase of the

target species

but before seed

maturity. Predo

minately in the

spring/summer/autumn period

1-4 28 days

0.06-0.12500-1000 0.6

Australia sedges 0.025-0.2727

550-1000 0.25-1.5

Tall rescue and rushes 0.15-0.3

500-1000 1.5

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Remarks (a) For crops, the EU and Codex classifications (both) should be used; where relevant, the use situation should be described (e.g. fumigation of a structure)

(b) Outdoor or field use (F), glasshouse application (G) or indoor application (I) (c) e.g. biting and suckling insects, soil born insects, foliar fungi, weeds(d) e.g. wettable powder (WP), emulsifiable concentrate (EC), granule (GR)(e) GCPF Codes - GIFAP Technical Monograph No 2, 1989(f) All abbreviations used must be explained(g) Method, e.g. high volume spraying, low volume spraying, spreading, dusting, drench(h) Kind, e.g. overall, broadcast, aerial spraying, row, individual plant, between the plants -

type of equipment used must be indicated

(i) g/kg or g/l(j) Growth stage at last treatment (BBCH Monograph, Growth Stages of Plants, 1997,

Blackwell, ISBN 3-8263-3152-4), including where relevant, information on season at time of application

(k) The minimum and maximum number of application possible under practical conditions of use must be provided

(l) PHI - minimum pre-harvest interval(m) Remarks may include: Extent of use/economic importance/restrictions

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2. Applicant and Staff hazard classifications of the mixtureTable 4 Applicant and Staff classifications of the mixture

Hazard Class/Subclass

Mixture classification Method of classification

RemarksApplicant’s classification

Staff’s classification

Mix

ture

dat

a

Rea

d ac

ross

rule

s1

Class 1 Explosiveness NA ND

Class 2, 3 & 4 Flammability NA ND

Class 5 Oxidisers/Organic Peroxides

NAND

Subclass 8.1 Metallic corrosiveness

NAND

Subclass 6.1 Acute toxicity (oral) 6.1B 6.1C

Mainly paraquat dichloride

Difference appears to be a different interpretation of mixture rules

Subclass 6.1Acute toxicity (dermal)

6.1B 6.1BMainly paraquat dichloride

Subclass 6.1 Acute toxicity (inhalation)

6.1A 6.1AParaquat dichloride

Subclass 6.1 Aspiration hazard NA ND

Subclass 6.3/8.2 Skin irritancy/corrosion


Subclass 6.4/8.3 Eye irritancy/corrosion

6.4A 6.4AMainly paraquat dichloride

Subclass 6.5A Respiratory sensitisation

NAND

Subclass 6.5B Contact sensitisation

NAND

Subclass 6.6 Mutagenicity NA ND

Subclass 6.7 Carcinogenicity NA ND

1 Use of mixture rules may not adequately take into account interactions between different components in some circumstances and must be considered of lower reliability than data on the mixture itself.

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Hazard Class/Subclass

Mixture classification Method of classification

RemarksApplicant’s classification

Staff’s classification

Mix

ture

dat

a

Rea

d ac

ross

rule

s

Subclass 6.8 Reproductive/ developmental toxicity

NAND

Subclass 6.8 Reproductive/ developmental toxicity (via lactation)

NAND

Subclass 6.9 Target organ systemic toxicity2

6.9A6.9A

Paraquat dichloride

Subclass 9.1 Aquatic ecotoxicity 9.1A 9.1AParaquat dichloride

Subclass 9.2 Soil ecotoxicity NA ND

Subclass 9.3 Terrestrial vertebrate ecotoxicity


Subclass 9.4 Terrestrial invertebrate ecotoxicity

9.4B 9.4BParaquat dichloride

-: No information provided by the applicant

NA: Not Applicable --> For instance when testing is technically not possible: testing for a specific endpoint may be omitted, if it is

technically not possible to conduct the study as a consequence of the properties of the substance: e.g. very volatile, highly reactive or

unstable substances cannot be used, mixing of the substance with water may cause danger of fire or explosion or the radio-labelling of

the substance required in certain studies may not be possible.

ND: No Data or poor quality data (according to Klimisch criteria3) --> There is a lack of data for one or more components.

No: Data are available for the formulation or for all components and classification is not triggered.

3. Mammalian toxicology

3.1. Studies submitted with the formulation and the active ingredient technical concentrate

The applicant submitted a number of toxicity studies with the paraquat dichloride technical concentrate (44%

paraquat dichloride) and for a formulation coded “PARAQUAT 20% SL”, containing 200 g/L paraquat

2 When appropriate include separate rows to address single as well as repeat dose target organ toxicity, and any of the relevant routes (oral, dermal and/or inhalation).3 Klimisch, H-J., Andrear, M., & U. Tillmann, 1997. A systematic approach for evaluating the quality of experimental toxicological and ecotoxicological data. Reg. Toxicol. Pharmacol. 25, 1–5 (1997)

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dichloride. The amount of paraquat dichloride in PARAQUAT 20% SL is less than the amount of paraquat

dichloride in Para-Ken 250 Herbicide, which contains 250 g paraquat dichloride/L. The applicant provided a

bridging statement where reasons are presented to read-across the data from “PARAQUAT 20% SL” to the

Para-Ken 250 Herbicide. The applicant claims that the toxicological studies for Human health for the 20%

formulated product will be closely similar or the same for the 25%. This conclusion is stated to be based on

the results for the 44% Active and comparing them to the 20%. The applicant states that the results for a

number of the LD50 tests are stated to be nearly identical between the 20% and 44%, suggesting that the

results for the 20% formulation can be read across to the 25% formulation Para-Ken 250 Herbicide.

However, Staff note that while the results were similar in the majority of cases, in some tests there were

substantial differences. For example, in the acute dermal toxicity test with the 20% formulation mortality was

observed in all animals at 4000 mg/kg bw whereas with the technical concentrate (which contains a higher

concentration of paraquat dichloride) only 1/10 animals died at this dose. In addition, the composition of

“PARAQUAT 20% SL” was not provided so it was not possible to compare its composition with that of Para-

Ken 250 Herbicide. Therefore Staff have used mixture rules rather than the test data to classify Para-Ken

250 Herbicide.

4. Ecotoxicology

4.1. Robust study summaries for the formulation

The applicant provided ecotox studies performed with a formulation coded “PARAQUAT 20% SL”, containing

200 g/L paraquat dichloride. The amount of paraquat dichloride in PARAQUAT 20% SL is less than the

amount of paraquat dichloride in Para-Ken 250 Herbicide, which contains 250 g paraquat dichloride/L. The

applicant provided a bridging statement where reasons are presented to read-across the data from

“PARAQUAT 20% SL” to the Para-Ken 250 Herbicide. The applicant claims that since the difference in the

amount of paraquat dichloride between the two formulations is 50 g/L the results may be used in the risk

assessment. Staff summarised the studies provided by the applicant and used the results when deemed

appropriate for the risk assessment. Classification of Para-Ken 250 Herbicide was carried out according to

mixture rules.

4.1.1. Aquatic toxicity

Fish acute toxicity (Freshwater species)

Type of study Full test

Flag Supplemental study, formulation is not Para-Ken 250 Herbicide

Test Substance PARAQUAT 20% SL (containing 210 g/L paraquat dichloride)

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Species Danio rerio (zebrafish)

Type of exposure Semi-static for 96 hours, daily renewal

Endpoint LC50

Value 141.42 mg/L, equivalent to 28.28 mg paraquat dichloride/L.

ReferencePM Bidinotto (2008) Acute toxicity of PARAQUAT 20% SL to fish Danio rerio.

BIOAGRI, Piracicaba, Brazil. Study No 5258.208.365.08

Klimisch Score 1

Amendments/Deviations None

GLP Yes

Test Guideline/s OECD 203 (1992)

No/Group 7 fish per treatment

Dose Levels0, 50, 200, 400, 800 mg/L (nominal concentrations)

Reference substance: potassium dichromate (0, 100, 180, 320 and 560 mg/L)

Analytical measurements At the beginning and end of the tests using HPLC/UV

Study Summary

The acute toxicity of PARAQUAT 20% SL to the zebrafish Danio rerio was

determined in a semi-static test for 96 hours. The validity criteria were fulfilled.

The deviations between measured and nominal concentrations ranged between

2.53 and 14.02%, thus lower than 20%, therefore the endpoint is expressed as

nominal concentration. The LC50 was 141.42 mg/L.

Conclusion The LC50 was 141.42 mg/L, equivalent to 28.28 mg paraquat dichloride/L.

Fish chronic toxicity (Freshwater species)

No study provided.

Invertebrate acute toxicity (Freshwater species)




Species Daphnia magna

Type of exposure Semi-static for 48 hours, renewal after 24h

Endpoint EC50

Value 17.43 mg/L

Reference JN Sesso (2008) Acute toxicity of PARAQUAT 20% SL to Daphnia magna.

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BIOAGRI, Piracicaba, Brazil. Study No 5258.206.370.08.

Klimisch Score 1


GLP Yes


No/Group 4 replicates of 5 Daphnids per treatment

Dose Levels

0, 6.5, 13, 25, 50, 100 mg/L (nominal concentrations)

Reference substance: potassium dichromate (0, 0.32, 0.56, 1.0, 1.8 and 2.4

mg/L)


Study Summary

The acute toxicity of PARAQUAT 20% SL to Daphnia magna was determined in

a semi-static test for 48 hours. Deviations from nominal concentrations ranged

from 3.64 to 15.85%, therefore all effect levels were based on nominal

concentrations. The validity criteria were fulfilled.

The 48-hour EC50 was 17.43 mg/L.

Conclusion The EC50 was 17.43 mg/L, equivalent to 3.5 mg paraquat dichloride/L.

Invertebrate chronic toxicity (Freshwater species)

No study provided.

Algae acute toxicity (Freshwater species)




Species Pseudokirchneriella subcapitata

Type of exposure Static for 72 hours

Endpoint ErC50 and EyC50

Value ErC50 = 2.41 mg/L; EyC50 = 0.88 mg/L

Reference

PM Bidinotto (2008) Toxicity of PARAQUAT 20% SL to alga

Pseudokirchneriella subcapitata. BIOAGRI, Piracicaba, Brazil. Study No

5258.202.359.08

Klimisch Score 1


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GLP Yes


No/Group 104 cells/mL

Dose Levels

0, 0.1, 0.32, 1, 3.2, 10 mg/L(nominal concentrations)

Reference substance: potassium dichromate (0, 0.18, 0.32, 0.56, 1.0 and 1.8

mg/L)


Study Summary

The aim of this study was to determine the effects of PARAQUAT 20% SL on

the growth rate and yield of the green alga over a period of 72 hours.

Deviations from nominal concentrations ranged from 0.4 to 11.75%, therefore

all effect levels were based on nominal concentrations. The study met the

validity criteria of the test guideline.

The 72-hour EyC50 was 0.88 mg/L (CI: 0.74 – 1.03 mg/L) and the 72-hour ErC50

was 2.41 mg/L (CI: 2.08 -2.80 mg/L).

ConclusionThe EyC50 was 0.88 mg formulation/L and the ErC50 was 2.41 mg

formulation/L.

General conclusion about aquatic toxicity classification

Para-Ken 250 Herbicide is classified as 9.1A, according to mixture rules.

4.1.2. Soil toxicity

Soil macro-invertebrates

Type of study Limit test



Species Eisenia foetida

Type of exposure Spiked soil for 14 days

Endpoint LC50

Value >1000 mg/kg soil

ReferenceRA Franco (2008) Acute toxicity of PARAQUAT 20% SL to earthworm Eisenia

foetida. BIOAGRI, Piracicaba, Brazil. Study No 5258.203.381.08

Klimisch Score 1


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GLP Yes


No/Group 4 replicates of 10 earthworms per treatment

Dose Levels0, 1000 mg/kg soil

Reference: chloroacetamide


Study Summary


the survival of the earthworm Eisenia foetida. The study met the validity criteria

of the test guideline.

The 14-day LC50 was higher than 1000 mg formulation/kg bw.

Conclusion The 14-day LC50 was higher than 1000 mg formulation/kg bw.

Non-target terrestrial plants

No study provided.

Nitrogen transformation test




Species Soil microflora


Endpoint Nitrogen transformation

Value No effects of PARAQUAT 20% SL at 3 kg paraquat dichloride per hectare.

Reference

VCB Cardinalli (2008) Effects of PARAQUAT 20% SL to soil microoganisms:

Nitrogen transformation test. BIOAGRI, Piracicaba, Brazil. Study No

5258.218.328.08

Klimisch Score 1


GLP Yes


No/Group 3 replicates per treatment

Dose Levels0, 0.6 kg paraquat dichloride/ha (maximum used rate), 3 kg paraquat

dichloride/ha (5*MUR)

Analytical measurements At the beginning of the test in the stock solution using HPLC/UV

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Study Summary


soil microorganisms through a nitrogen transformation test using two different

Brazilian soils, a Latosoil (LVdf) and an Argisoil (PVAe) as test systems. The

study met the validity criteria of the test guideline. Two concentrations were

tested: 0.6 kg a.i./ha and 3 kg a.i./ha. The deviation at the end of the 28 days of

exposure between control and treated soils were below the 25% threshold.

ConclusionEffects of PARAQUAT 20% SL were below 25% at 3 kg paraquat dichloride

per hectare.

Carbon transformation test




Species Soil microflora


Endpoint Carbon transformation

Value No effects of PARAQUAT 20% SL at 3 kg paraquat dichloride per hectare.

Reference

VCB Cardinalli (2008) Effects of PARAQUAT 20% SL to soil microorganisms:

Carbon transformation test. BIOAGRI, Piracicaba, Brazil. Study No

5258.201.468.08

Klimisch Score 1


GLP Yes


No/Group 3 replicates per treatment

Dose Levels0, 0.6 kg paraquat dichloride/ha (maximum used rate), 3 kg paraquat

dichloride/ha (5*MUR)

Analytical measurements At the beginning of the test in the stock solution using HPLC/UV

Study Summary


soil microorganisms through a carbon transformation test using two different

Brazilian soils, a Latosoil (LVdf) and an Argisoil (PVAe) as test systems. The

study met the validity criteria of the test guideline. Two concentrations were

tested: 0.6 kg a.i./ha and 3 kg a.i./ha. The deviation at the end of the 28 days of

exposure between control and treated soils were below the 25% threshold.

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ConclusionEffects of PARAQUAT 20% SL were below 25% at 3 kg paraquat dichloride

per hectare.

General conclusion about soil toxicity classification

Para-Ken 250 Herbicide does not trigger a classification for soil toxicity.

4.1.3. Terrestrial vertebrate toxicity

Acute oral toxicity




Species Coturnix coturnix japonica (Japanese quail)

Type of exposure Acute oral

Endpoint LD50

Value 775.92 mg/kg bw

ReferenceRA Franco (2008) Avian acute toxicity test of PARAQUAT 20% SL in Japanese

quails. BIOAGRI, Brazil. Study No 5258.302.410.08.

Klimisch Score 2

Amendments/Deviations None that have impacted the results

GLP No

Test Guideline/s OPPTS 850.2100 (1996)

No/Group 10 (5 males and 5 females) per treatment

Dose Levels 0 (control), 257.2, 429.6, 717.4, 1198 and 2000 mg formulation/kg bw

Analytical measurements Not required

Study Summary PARAQUAT 20% SL was tested for acute oral toxicity in birds using the

Japanese quail. Twenty-one dosed quails (42%) died in the study. Compound-

related deaths were registered on 717.4 (1 or 10%), 1198 (10 or 100%) and

2000 (10 or 100%) mg/kg bw. Dose-related clinical signs (apathy, ataxia, ruffled

feathers, dyspnea, sialorrhea and decubitus) were acute neurological and

respiratory signs observed on 717.4, 1198 and 2000 mg/kg bw. No animal from

control groups, 257.2 and 429.6 mg/kg bw presented any clinical sign during

the 14-day observation period. The validity criteria were met. The combined

(males and females) LD50 of the test substance PARAQUAT 20% SL was

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775.92 mg/kg bw.

Conclusion The LD50 was 775.92 mg formulation/kg bw.

General conclusion about toxicity to terrestrial vertebrate classification

Para-Ken 250 Herbicide is classified as 9.3A, according to mixture rules.

4.1.4. Ecotoxicity to terrestrial invertebrates

Bees – Laboratory studies




Species Apis mellifera

Type of exposure 48 hours, contact

Endpoint LD50

Value 41.23 µg/bee (equivalent to 8.25 µg a.i./bee)

Reference

RA Franco (2008) Acute contact toxicity test of PARAQUAT 20% SL to

honeybee Apis mellifera (africanized). BIOAGRI, Brazil. Study No

5258.204.385.08.

Klimisch Score 1

Amendments/Deviations None that have impacted the results

GLP Yes


No/Group 3 replicates with 10 bees per treatment

Dose Levels

0, 7.8125, 15.625, 31.25, 62.25 and 125 µg/bee (nominal concentrations),

equivalent to 1.5625, 3.125, 6.25, 12.5 and 25 µg a.i./bee

Reference item: dimethoate

Analytical measurements Not required

Study SummaryThe acute contact toxicity of PARAQUAT 20% SL to the honeybee was tested.

The validity criteria were met. The LD50 (48 hours) was 41.23 µg a.i./bee.

Conclusion LD50 = 41.23 µg/bee (equivalent to 8.25 µg a.i./bee)

General conclusion about toxicity to terrestrial invertebrate classification

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Para-Ken 250 Herbicide is classified as 9.4B, according to mixture rules.

5. Human health risk assessment5.1.1. Para-Ken 250 Herbicide contains paraquat dichloride and is proposed to be used in a higher

application rate than other approved substances containing this active ingredient. Therefore, a quantitative human health risk assessment was undertaken.

Quantitative worker (operator) risk assessment

Critical endpoint definition

Using an existing AOEL for paraquat

Available international AOELs

Key systemiceffect

NOAELmg/kg bw/Day

Uncertainty factors

AOELmg/kg bw/Day

Staff’s modifications Remarks

EU (2003)

Pulmonary lesions, clinical chemistry, and urine analysis

(90 day and 1 year dog studies)

0.45 100

AOEL short term: 0.0005

AOEL long term: 0.0004

NoneCorrected for 10% oral absorption

Other inputs for human worker (operator) and re-entry exposure modelling4

ActivePhysical form

Concentration of each active (g/L)

Maximum application rate (for each active, for each method of application)

g a.i./ha

Dermal absorption (%)

AOELmg/kg bw/dayConcentrate Spray

Paraquat ion

Liquid 1500 6 30 0.0005

Comments on inputs for human worker (operator) exposure modelling input parameters:

Dermal absorption

4 The EPA’s operator exposure assessment is based on a modification of the approach used by European regulators. Full details of the methodology can be provided on request.

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Dermal absorption data for paraquat in the formulation Para-Ken 250 were not provided. In the absence of

specific data Staff consider it is appropriate to use default values for dermal absorption, as recommended in

EFSA guidance on Guidance on Dermal Absorption (20125) and OECD Guidance Notes on Dermal

Absorption (20116). For pesticides, Staff have agreed to adopt less conservative default values than those

proposed in the EFSA and OECD guidance, using default values proposed by Aggarwal et al (20157), which

are based on a review of a robust data set of 295 in vitro human dermal absorption studies with over 150

agrochemical active ingredients. These default values are 2% for solid concentrates, 6% for liquid

concentrates and 30% for spray dilutions.

Staff note that the oral absorption of paraquat is low (10% for paraquat). Staff considered whether it may be

possible to use this information to refine the dermal absorption values however no oral absorption,

distribution, metabolism and excretion (ADME) studies are available with the Para-Ken 250 Herbicide

formulation and the influence of the co-formulants in this formulation on dermal absorption is unknown.

Therefore staff do not consider it appropriate to use oral absorption as a surrogate dermal absorption value.

Staff also note that assessments of the EU and the US EPA have noted that dermal absorption of paraquat

may be as low as 0.5%, however these conclusions predate the introduction of the OECD and EFSA

guidance on dermal absorption which provides criteria for deciding when it is appropriate to read across data

to a specific formulation. In this case information is not available as to the formulations or vehicles used to

perform the dermal absorption studies with paraquat and how these compare to the Para-Ken 250 Herbicide

formulation.

In the absence of more information Staff consider it is appropriate to use the default dermal absorption

values in the present assessment, however it is acknowledged that these values may result in an

overestimate of exposure.

Work rates

Para-Ken 250 Herbicide is intended to be used the control of weeds in Lucerne, Clover seed crops, Forestry,

Industrial site, Streets and for Barley grass control by high volume broadcast and by hand gun. The default

work rate for boom spraying for cereals, legume vegetables, bare soil and grasslands in the EPA exposure

assessment model is 50 ha per day. Staff have assumed that this work rate is appropriate for the proposed

uses of Para-Ken 250 Herbicide.

The default work rate for knapsack/hand gun spraying is 1 ha per day.

Output of human worker (operator) mixing, loading and application exposure modelling

5 EFSA 2012 Guidance on dermal absorption. EFSA Panel on Plant Protection Products and their Residues. EFSA Journal 2012: 10(4):2665 http://ec.europa.eu/food/plant/pesticides/guidance_documents/docs/efsa_guidance_document_dermal_absorption_18042012.pdf Accessed 05/02/20166 OECD 2011 OECD Guidance notes on dermal absorption. Series on Testing and Assessment, No. 156. ENV/JM/MONO(2011)36 http://www.oecd.org/chemicalsafety/testing/48532204.pdf Accessed 05/02/20167 Aggarwal et al. 2015 Assessment of an extended dataset of in vitro human dermal absorption studies on pesticides to determine default values, opportunities for read-across and influence of dilution on absorption. Regul Toxicol Pharmacol 72: 58-70. http://www.sciencedirect.com/science/article/pii/S0273230015000458

April 2016

http://www.sciencedirect.com/science/article/pii/S0273230015000458

http://www.oecd.org/chemicalsafety/testing/48532204.pdf

http://ec.europa.eu/food/plant/pesticides/guidance_documents/docs/efsa_guidance_document_dermal_absorption_18042012.pdf

http://ec.europa.eu/food/plant/pesticides/guidance_documents/docs/efsa_guidance_document_dermal_absorption_18042012.pdf

20

Exposure Scenario Estimated operator exposure (mg/kg bw/day) Risk Quotient

Boom

No PPE8 during mixing, loading and application 0.8117 1623.43

Gloves only during mixing and loading 0.6729 1345.71

Gloves only during application 0.7018 1403.57

Full PPE during mixing, loading and application (excluding respirator)

0.0560 112.07

Full PPE during mixing, loading and application (including FP1, P1 and similar respirator achieving 75 % inhalation exposure reduction)

0.0546 109.11


0.0543 108.60

Backpack - High Level Target

No PPE during mixing, loading and application 0.5308 1061.57

Gloves only during mixing and loading 0.2936 587.14

Gloves only during application 0.4695 938.91

Full PPE during mixing, loading and application (excluding respirator)

0.0503 100.50


0.044316 88.63


0.043191 86.38

Outcomes of the worker (operator) exposure assessment

Predicted exposures of workers (operators) during mixing, loading and application of Para-Ken 250

Herbicide are greater than the AOEL for paraquat for both boom and knapsack spraying, even with the use

of full PPE including a respirator9.

Re-entry exposure assessment

8 Full” PPE includes: gloves, hood/visor, coveralls, and heavy boots during application. The model only provides for use of gloves at mixing loading.9 Gloves, hood/visor, coveralls, and heavy boots with a respirator

April 2016

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Para-Ken 250 Herbicide is intended to be used primarily before sowing or transplanting, or before crop

emergence. Therefore staff anticipate that re-entry worker exposure to Para-Ken 250 Herbicide is likely to be

minimal and no quantitative re-entry worker exposure assessment is required.

Quantitative bystander risk assessment10

The AOEL derived for operator and re-entry worker assessment above is also used for the bystander

assessment calculations.

Output of human bystander exposure modelling11

Exposure Scenario

Estimated exposure of 15 kg toddler exposed through contact to surfaces 8 m from an application area(µg/kg bw/day)

Risk Quotient

Buffer zone needed to reduce toddler exposure to the AOEL

Boom

High boom, fine droplets 10.54 21.0817 136

High boom, coarse droplets 1.67 3.3446 30

Low boom, fine droplets 3.56 7.1143 70

Low boom, coarse droplets 0.85 1.6924 16

Staff note that the intended use pattern for Para-Ken 250 Herbicide includes Street verges. It is possible that

in some cases children may play on such areas. Therefore Staff have also assessed the potential

recreational exposure for children. This uses the same approach as the bystander exposure assessment;

apart from the fact that the area of contact is 0 m from the application area.

Output of recreational exposure modelling

Estimated exposure of 15 kg toddler exposed through contact to surfaces 0 m from an application area(µg/kg bw/day)

Risk Quotient

10 The Staff considers that the main potential source of exposure to the general public for substances of this type (other than via food

residues which will be considered as part of the registration of this substance under the Agricultural Compounds and Veterinary

Medicines (ACVM) Act 1997) is via spray drift. In terms of bystander exposure, toddlers are regarded as the most sensitive sub-

population and are regarded as having the greatest exposures. For these reasons the risk of bystander exposure is assessed in this

sub-population. EPA has agreed that the AOEL used for operator and re-entry worker exposure assessment should be used for the

bystander assessment, as the use of an oral chronic reference dose (CRfD) is usually likely to be over precautionary. 11 The EPA’s bystander exposure assessment is based on a modification of the approaches used by European regulators and the US

EPA. Full details of the methodology can be found in Appendix X.. Spray drift deposition from ground based application is estimated

using the AgDisp model. Spray drift deposition from aerial application is estimated using the AGDISP model along with appropriate New

Zealand input parameters.

April 2016

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108 216

Outcomes of the bystander exposure assessment

Predicted exposures of bystanders are greater than the AOEL for paraquat. If spraying of Para-Ken 250

Herbicide were limited to use of coarse droplets, minimum buffer zones of 16 or 30 metres from sensitive

areas would be required for low boom or high boom application, respectively, in order to reduce exposures to

the AOEL.

Exposures for children playing directly on a treated area are also substantially higher than the AOEL.

5.2. Summary and conclusions of the human health risk assessment

Predicted exposures of operators during mixing, loading and application of Para-Ken 250 Herbicide are

greater than the AOEL for paraquat, even with the use of full PPE including a respirator.

Based on the use pattern re-entry worker exposure to Para-Ken 250 Herbicide is likely to be minimal and

therefore no quantitative re-entry worker exposure assessment has been performed.

Predicted exposures of a bystander 8 metres away from the edge of an application area are greater than the

acceptable levels for both active ingredients. If spraying of Para-Ken 250 Herbicide were limited to use of

coarse droplets, minimum buffer zones of 16 or 30 metres from sensitive areas would be required for low

boom or high boom application, respectively, in order to reduce exposures to the AOEL.

Predicted exposures for children playing directly on a treated area are also substantially higher than the

AOEL.

The risk assessment includes a number of default assumptions which leads to conservatism in the risk

assessment. Information that could potentially be used to refine the risk assessment includes:

Dermal absorption data for the active ingredients in the Para-Ken 250 formulation

Information on the expected work rates per day for each use scenario

Operator exposure studies

Confirmation that the application rate relates to the paraquat ion

Information on the relevance of the recreational exposure scenario included in the present risk

assessment

However, with regard to dermal absorption, Staff note that even if the low value of 0.5% absorption proposed

by the EU in 2002 were confirmed as being suitable for use in the risk assessment, this would lead to

predicted exposures greater than the AOEL for operators mixing, loading and applying Para-Ken 250

Herbicide by boom and knapsack application methods (RQs of 4 and 6, respectively).

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6. Environmental risk assessmentPara-Ken 250 Herbicide contains paraquat dichloride and is proposed to be used in a higher application rate than other approved substances containing paraquat dichloride. Therefore, a quantitative risk assessment for the environment was undertaken.

6.1. Robust studies with the active ingredient

The information on the environmental fate and behaviour and ecotoxicological data of paraquat dichloride

are depicted in Table 1 and Table 2.

April 2016

Table 3: Summary of environmental fate data on paraquat dichloride

Test Paraquat dichloride

HydrolysisHydrolytically stable at pH 5, 7 and 9 after 30

days at 25 and 40 °C.

Rapid biodegradation in

waterNot rapidly biodegradable.

Aqueous photolysisPhotolytically stable at environmentally

relevant wavelengths.

Aerobic degradation in water

(water/sediment)-

Anaerobic degradation -

Bioaccumulation

The log Kow for paraquat dichloride is -4.5 at

20 °C indicating that bioaccumulation is

unlikely.

Aerobic degradation in soil

(laboratory)

Paraquat is expected to be almost immobile

in soil. The estimated average field half-life

of paraquat in soil is 1000 days.

Aerobic degradation in soil

(field)

No half-life calculated, estimates indicate

more than 10 years.

Soil photolysis -

Adsorption/desorption

(Koc values)Koc = 1000000

Volatilisation Not relevant, due to low vapour pressure.

- No data provided

25

Table 4: Summary of ecotoxicological data on paraquat dichloride – Values in bold are used for the risk assessment.

Test Paraquat dichloride Reference Paraquat 20% SL

Acute / fishLC50 = 10.85 mg/L (Barbus sharpeyi)

EPA internal database

LC50 = 141.42 mg/L, equivalent to 28.28 mg a.i./L)

Acute / aquatic invertebrates

EC50 = 1.2 mg/L (Daphnia magna)


EC50 = 17.43 mg/L, equivalent to 3.49 mg a.i./L

Algae EC50 = 0.32 mg/L (Selenastrum capricornutum)


ErC50 = 2.41 mg/L, equivalent to 0.48 mg a.i/L

(Pseudokirchneriella subcapitata)

Algae - diatomEC50 = 0.00055 mg/L (Naviculla peliculosa)


-

Aquatic plant

(Lemna gibba)EC50 = 0.098 mg/L


-

Chronic / fish - - -

Chronic / Aquatic invertebrates

NOEC = 0.12 mg/L

(Daphnia magna)SANCO, 2003 -

Chronic toxicity sediment dwelling organism - Chironomus

NOEC = 100 mg/kg (sediment);

NOEC = 0.367 mg/L (water phase only)

SANCO, 2003 -

Acute / EarthwormLC50 > 1380 mg/kg soil


LC50 > 210 mg a.i./kg soil

Chronic / Earthworm - - -

Soil microorganisms

No adverse effects were observed after application up to 720 kg ai/ha in one year.

SANCO, 2003

No adverse effects on carbon and nitrogen transformations after application up to 3 kg a.i./ha.

Non target plants EC25 = 0.95 kg/ha (seedling emergence, cocklebur)

EC25 = 0.015 kg/ha (vegetative vigour,


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cocklebur)

NOEC = 0.004 kg/ha (vegetative vigour, cocklebur)

Acute / birdLD50 = 35 mg/kg bw

LD50 = 176 mg/kg bw

SANCO, 2003


LD50 = 775.92 mg/kg bw, equivalent to 155.2 mg a.i./kg bw

Reproduction birdNOEC = 2.8 mg/kg bw/d

USEPA, 1997

SANCO, 2003-

Acute / bees

LD50 (contact) = 9.26 µg/bee

LD50 (oral) = 9.06 µg/bee (120-hr study)


SANCO, 2003

LD50 (contact) = 41.23 µg/bee (equivalent to 8.25 µg a.i./bee)

Non target arthropods - - -

- No data provided

6.2. Risk assessment Methodology

Methods used to assess environmental exposure and risk differ between environmental compartments

(Table 5).

Table 5 Reference documents for environmental exposure and risk assessments

Environmental exposure Risk assessment

Aquatic organisms (GEN)eric (E)stimated (E)nvironmental (C)oncentration Model Version 2.0 – 01 August

Overview of the Ecological Risk Assessment Process in the Office of Pesticide Programs, U.S. Environmental Protection Agency. Endangered and threatened Species Effects Determinations –

April 2016

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2002

AgDrift and EPA Software1223 January 2004

Sediment organisms

Guidance on information requirements and

chemical safety assessment, Chapter R.16: Environmental Exposure Estimation, Version: 2 - May 2010

Guidance on information requirements and chemical safety assessment, Chapter R.10: Characterisation of dose [concentration]-response for environment – May 2008

Soil organisms, invertebrates (macro-invertebrates)

Soil persistence models and EU registration. The final report of the work of the Soil Modelling Work group of FOCUS (FOrum for the Co-ordination of pesticide fate models and their USe) – 29 February 1997

SANCO/10329/2002 rev 2 final. Guidance Document on terrestrial ecotoxicology under Council Directive 91/414/EEC- 17 October 2002

BeesGuidance for assessing pesticide risks to bees. US EPA, Health Canada Pest Management Regulatory Agency, California Department of Pesticide Regulation, 19 June 2014

Terrestrial organisms, invertebrates (non-target arthropods)

Guidance document on regulatory testing and risk assessment procedures for plant protection products with non-target arthropods. From ESCORT 2 Workshop – 21/23 March 2000

Terrestrial vertebrates (birds)

Guidance of EFSA. Risk assessment to birds and mammals – 17 December 2009.

EFSA calculator tool - 200913

SANCO/4145/2000 final. Guidance Document on risk assessment for birds and mammals under Council Directive 91/414/EEC- 25 September 2002

Secondary poisoning and biomagnification

Technical Guidance Document on risk assessment in support of Commission Directive 93/67/EEC on Risk Assessment for new notified

Guidance of EFSA. Risk assessment to birds and mammals – 17 December 2009

EFSA calculator tool - 2009

12 The Staff used two different models for assessing the EEC and associated risks: Generic Estimated Environmental Concentration Model v2 (GENEEC2) surface water exposure model (USEPA,

2001) estimates the concentration of substance in surface water which may arise as a result of surface runoff and spraydrift.

To examine how buffer zones would reduce the active ingredient concentrations in receiving waters, the Staff used the AgDRIFT® model (developed under a cooperative Research and Development Agreement, CRADA, between the EPA, USDA, US Forest Service, and SDTF). AgDRIFT® incorporates a proposed overall method for evaluating off-site deposition of aerial, orchard or ground applied pesticides, and acts as a tool for evaluating the potential of buffer zones to protect sensitive aquatic and terrestrial habitats from undesired exposures. Calculations are made assuming the receiving water is a 30 cm deep pond. The model is used to estimate the buffer zone that would reduce exposure through spray drift to such a concentration that an acute risk quotient of 0.1 cannot be calculated. It is noted that unlike GENEEC2, AgDRIFT® model only considers transport by spray drift, input through runoff, volatilisation, etc. will pose additional risks.

13 www.efsa.europa.eu/en/efsajournal/pub/1438.htm

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substances, Commission Regulation (EC) No 1488/94 on Risk Assessment for existing substances, Directive 98/8/EC of the European Parliament and of the Council concerning the placing of biocidal products on the market – Part II - 2003

SANCO/4145/2000 final. Guidance Document on risk assessment for birds and mammals under Council Directive 91/414/EEC- 25 September 2002

6.3. Consideration of threatened native species

No studies are requested to be conducted on native New Zealand species; the risk assessment is based on

studies performed on standard surrogate species from Europe or North America. Uncertainty factors

included in the risk assessment process encompass the possible susceptibility variations between the

surrogate species and the native New Zealand species. However, these factors are designed to protect

populations not individual organisms. EPA staff acknowledge that these factors may not be protective

enough for threatened species for which the survival of the population could depend on the survival of each

and every individual.

Therefore, the US EPA approach for risk assessment of endangered species has been implemented.

Additional uncertainty factors are included, depending on the type of organisms. US EPA consider higher

factors when organisms cannot escape the contaminated area (for aquatic organisms for instance) than for

birds.

US EPA has not defined any additional factor for soil organisms except for plants, so EPA staff applied the

same approach as for aquatic environment, considering that soil invertebrates won’t be able to escape from

the contaminated area.

For the purpose of this risk assessment, the threatened species are those included in the following

categories of the New Zealand Threat Classification System: threatened (Nationally critical, Nationally

endangered, Nationally vulnerable) and at risk (declining, recovering, relict, and naturally uncommon).

6.4. Aquatic risk assessment

For Class 9 substances, irrespective of the intrinsic hazard classification, the ecological risk can be assessed

for a substance by calculating a Risk Quotient (RQ) based on an estimated exposure concentration. Such

calculations incorporate toxicity values, exposure scenarios (including spray drift, leaching and run-off,

application rates and frequencies), and the half-lives of the component(s) in water. For the aquatic

environment, the calculations provide an Estimated Environmental Concentration (EEC) which, when divided

by the L(E)C50 or a NOEC, gives a RQ acute or chronic.

RQ=EECshort−term

L (E )C50

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Chronic RQ=EEC long−term

NOEC

If the RQ exceeds a predefined level of concern, this suggests that it may be appropriate to refine the

assessment or apply the approved handler control and/or other controls to ensure that appropriate matters

are taken into account to minimize off-site movement of the substance. Conversely, if a worst-case scenario

is used, and the level of concern is not exceeded, then in terms of the environment, there is a presumption of

low risk which is able to be adequately managed by such things as label statements (warnings, disposal).

The approved handler control can then be removed on a selective basis.

Levels Of Concern (LOC) developed by the USEPA (Urban and Cook, 1986) and adopted by EPA determine

whether a substance poses an environmental risk (Table 6).

Table 6 Levels of concern as adopted by EPA New Zealand

Endpoint LOC Presumption

Aquatic (fish, invertebrates, algae, aquatic plants)

Acute RQ ≥ 0.5 High acute risk

Acute RQ 0.1 - 0.5 Risk can be mitigated through restricted use

Acute RQ < 0.1 Low risk

Chronic RQ ≥ 1 High chronic risk

Aquatic threatened species

Acute RQ ≥ 0.05 High acute risk

Chronic RQ ≥ 0.1 High chronic risk

Plants (terrestrial)

Acute RQ /TER

RQ ≥ 1 calculated on the basis of EC25 or TER < 5 calculated on the basis of EC50

High acute risk

Threatened plants species (terrestrial)

Acute RQ≥ 1 calculated on the basis of the NOEC or EC05

High acute risk

6.4.1. GENEEC2 modelling

Calculation of expected environmental concentrations

The parameters used in GENEEC2 modelling are listed in Table 7.

Table 7 Input parameters for GENEEC2 analysis

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Clover seed crops

Non-crop situations: fence lines, streets, industrial sites

Forestry Lucerne Non selective weed control (barley grass)

Application rate (g a.i./ha)

4001500 1000 600 600 - 1500

Application frequency 1-2 1-4 1-2 1-2 1-4

Application interval (days)

28 days

Koc* 15 473

Aerobic soil DT50

(days)1000

Pesticide wetted in? No

Methods of applicationHV broadcast HV broadcast,

knapsack, handgun

HV broadcast

HV broadcast

Handgun

‘No spray’ zone No

Water solubility (ppm) 620 000

Hydrolysis (DT50 in days)

Stable

Aerobic aquatic DT50

whole system (days)**2000

Aqueous photolysis DT50 (days)

Stable

Highest concentration Peak EEC (mg/L)

0.00437

0.03223 0.01091 0.00652 Low dose = 0.01284

High dose = 0.03223

*Lowest value of a non sand soil

** Twice the value of the DT50 soil according to the GENEEC2 recommendations

Output from the GENEEC2 model for paraquat dichloride

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RUN No. 1 FOR Paraquat dichlor ON Clover * INPUT VALUES * -------------------------------------------------------------------- RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) (FT) (IN) -------------------------------------------------------------------- 0.356( 0.705) 2 28 15473.0******* GRHIFI( 6.6) 0.0 0.0

FIELD AND STANDARD POND HALFLIFE VALUES (DAYS) -------------------------------------------------------------------- METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED (FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND) -------------------------------------------------------------------- 1000.00 2 0.00 0.00- 0.00 ****** 2000.00

GENERIC EECs (IN MICROGRAMS/LITER (PPB)) Version 2.0 Aug 1, 2001 -------------------------------------------------------------------- PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC -------------------------------------------------------------------- 4.37 4.17 3.19 1.92 1.43

RUN No. 2 FOR Paraquat dichlor ON Non crop s * INPUT VALUES * -------------------------------------------------------------------- RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) (FT) (IN) -------------------------------------------------------------------- 1.335( 5.190) 4 28 15473.0******* GRHIFI( 6.6) 0.0 0.0

FIELD AND STANDARD POND HALFLIFE VALUES (DAYS) -------------------------------------------------------------------- METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED (FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND) -------------------------------------------------------------------- 1000.00 2 N/A 0.00- 0.00 ****** 2000.00


RUN No. 3 FOR Paraquat dichlor ON Forestry * INPUT VALUES * -------------------------------------------------------------------- RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) (FT) (IN) -------------------------------------------------------------------- 0.890( 1.764) 2 28 15473.0******* GRHIFI( 6.6) 0.0 0.0

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RUN No. 4 FOR Paraquat dichlor ON Lucerne * INPUT VALUES * -------------------------------------------------------------------- RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) (FT) (IN) -------------------------------------------------------------------- 0.534( 1.058) 2 28 15743.0******* GRHIFI( 6.6) 0.0 0.0



RUN No. 5 FOR Paraquat dichlor ON Non select * INPUT VALUES * -------------------------------------------------------------------- RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) (FT) (IN) -------------------------------------------------------------------- 0.534( 2.076) 4 28 15743.0******* GRHIFI( 6.6) 0.0 0.0


April 2016

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The maximum Estimated Environmental Concentration (EEC) for paraquat dichloride when used in Para-

Ken 250 Herbicide for clover, forestry, lucerne, non-crop situations and non-selective weed control (barley

grass) high and low rate estimated by GENEEC2 were 0.00433 mg/L, 0.01091 mg/L, 0.00652 mg/L,

0.03223 mg/L and 0.01284 mg/L, respectively.

Calculation of acute risk quotients using GENEEC2 expected environmental concentrations

Table 8 gives calculated acute risk quotients for each trophic level considering EEC estimated by GENEEC2

and lowest relevant toxicity figures.

The calculations are based on a conservative model taking into account the degradation of the substance

and its adsorption potential in order to cover both run-off, drift input into water bodies. The model also

considers information about the application method to determine the drift input into water bodies.

Table 8 Acute risk quotients derived from the GENEEC2 model and toxicity data

SpeciesPeak EEC from GENEEC2 (mg/L)

LC50 or EC50

(mg/L)Acute RQ

Trigger value / Presumption

Clover - 0.4 kg a.i./ha, 2 applications at 28 days interval

Fish 0.00437

10.850.0004

< 0.1 / Risk below concern

< 0.05 / Risk below concern for threatened species

Invertebrates 1.2 0.0036



Algae - 0.32 0.014 < 0.1 / Risk below

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LC50 or EC50

(mg/L)Acute RQ


Selenastrum capricornutum

concern


Algae - diatom

(Navicula pelliculosa)

0.00055 7.94> 0.5 / High risk

> 0.05 / High risk for threatened species

Aquatic plant

(Lemna gibba)0.098 0.045



Forestry - 1 kg a.i./ha, 2 applications at 28 days interval

Fish

0.01091

10.85 0.001



Invertebrates

(Daphnia magna)1.2 0.009



Algae - Selenastrum capricornutum

0.32 0.034



Algae - diatom


0.00055 19.84> 0.5 / High risk


Aquatic plant


0.1-0.5 / Risk can be mitigated through restricted use


Lucerne - 0.6 kg a.i./ha, 2 applications at 28 days interval

0.00652 10.85 0.0006 < 0.1 / Risk below

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LC50 or EC50

(mg/L)Acute RQ


Fish

concern


Invertebrates





0.32 0.02



Algae - diatom


0.00055 11.85> 0.5 / High risk


Aquatic plant




Barley grass control – 1.5 kg a.i./ha, 4 applications at 28 days interval

Fish 0.03223

10.85 0.00297



Invertebrates





0.32 0.1 < 0.1 / Risk below concern


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LC50 or EC50

(mg/L)Acute RQ


Algae - diatom


0.00055 58.6> 0.5 / High risk


Aquatic plant




Barley grass control, lower rate – 0.6 kg a.i./ha, 4 applications at 28 days interval

Fish

0.01284

10.85 0.0011



Invertebrates





0.32 0.04



Algae - diatom


0.00055 23.35> 0.5 / High risk


Aquatic plant




Non-crop situations – 1.5 kg a.i./ha, 4 applications at 28 days interval

Fish 0.03223 10.85 0.00297 < 0.1 / Risk below concern


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LC50 or EC50

(mg/L)Acute RQ


Invertebrates





0.32 0.1



Algae - diatom


0.00055 58.6> 0.5 / High risk


Aquatic plant




Conclusion for the aquatic acute risk assessment using GENEEC2 data

Acute risks were below the level of concern for fish and aquatic invertebrates for all the use scenarios.

High acute risks for algae were observed for all use scenarios. High acute risks for threatened plant species

were observed for forestry, Lucerne, non selective weed control and non-crop situations.

Calculation of chronic risk quotients using GEENEC2 expected environmental concentrations

Table 9 gives calculated chronic risk quotients for each trophic level considering EEC estimated by

GENEEC2 and lowest relevant toxicity figures.

Table 9 Chronic risk quotients derived from the GENEEC2 model and toxicity data

SpeciesRelevant EEC from GENEEC2 (mg /L)*

NOEC(mg/L)

Chronic RQ


Clover seed - 0.4 kg a.i./ha, 4 applications at 28 days interval

Invertebrates Daphnia magna (21 d)

0.00319 0.12 0.026 < 1 / Risk below concern

< 0.1 / Risk below concern for threatened

April 2016

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species

Non-crop situations: Fence lines, streets, industrial - 1.5 kg a.i./ha, 4 applications at 28 days interval


0.02355 0.12 0.1965

< 1 / Risk below concern

> 0.1 / High chronic risk to threatened species

Forestry - 1 kg a.i./ha, 2 applications at 28 days interval


0.00797 0.12 0.066



Lucerne - 0.6 kg a.i./ha, 2 applications at 28 days interval


0.00474 0.12 0.0395



Barley grass control - 1.5 kg a.i./ha, 4 applications at 28 days interval


0.02355 0.12 0.19


> 0.1 / High chronic risk to threatened species

Barley grass control, low rate - 0.6 kg a.i./ha, 4 applications at 28 days interval


0.00933 0.12 0.077



* EEC selected must be as close as possible from the exposure duration of the study selected for risk assessment purpose.

Conclusion for the aquatic chronic risk assessment using GENEEC2 data

Chronic risks were below the level of concern for aquatic invertebrates, but high chornic risks for threatened

aquatic invertebrates species were observed for the application on non-crop situations and non-selective

control at the highest application rate of 1.5 kg paraquat dichloride per hectare. There were no data to

assess the chronic risks to fish. The staff consider that the lack of chronic data on fish does not prevent the

conclusion of the risk assessment.

AgDRIFT modelling

April 2016

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Further modelling using the AgDRIFT® tool was undertaken in order to refine this result and provide an

indication of the extent of the measures that would need to be taken in order to manage the risks so that they

are reduced below the level of concern that is indicated in the modelling.

AgDRIFT® modelling does not allow determining EEC per se. AgDRIFT® modelling output is a buffer zone

determination to be respected in order to get a risk quotient < 1.

Output from the AgDRIFTmodel

The AgDRIFT® tool utilises buffer zones as a means of mitigating risks to non-target organisms, with higher risks resulting in larger buffer zone distances as the model’s output. As such, the buffer zone outputs of the model provide a relative measure of the risks to the environment and the extent of the mitigation measures that should be applied. The results of the AgDRIFT® assessment confirmed that measures should be taken during use to ensure that waterways are not exposed to the substance.

Based on the application rates and proposed scenarios of use recommended for Para-Ken 250 Herbicide,

using coarse nozzles, the environmental fate characteristics and the lowest acute figure for the most

sensitive taxa (EC50 = 0.00055 mg/L) for paraquat dichloride on the diatom Navicula pelliculosa, the model

concludes that a buffer zone higher than 254 m (highest buffer zone possible to calculate in AgDrift) is

needed for all use scenarios. It should be pointed out that this buffer zone higher than 254 meters is already

applicable at 400 g a.i./ha, the lowest proposed application rate. Due to model limitations, it was not possible

to provide a quantitative estimate of exposure with known uncertainty, beyond the range of AgDRIFT. The

additional safety factor for threatened species was not taken into consideration because there is currently no

list of endangered algae species for NZ.

In conclusion, staff consider that there are no adequate mitigation measures to protect algae from the

application of Para-Ken 250 Herbicide.

6.5. Groundwater risk assessment

Estimated concentrations of chemicals with Koc values greater than 9995 L/kg are beyond the scope of the

regression data used in SCI-GROW model. The staff consider that due to the high adsorption of paraquat

dichloride and the fact that it is almost immobile in the soil will preclude a potential risk of groundwater

contamination.

6.6. Sediment risk assessment

Sediments may act as both a sink for chemicals through sorption of contaminants to particulate matter, and a

source of chemicals through resuspension. Sediments integrate the effects of surface water contamination

April 2016

40

over time and space, and may thus present a hazard to aquatic communities (both pelagic and benthic)

which is not directly predictable from concentrations in the water column.

When results from whole-sediment tests with benthic organisms are available the PNECsed has to be

derived from these tests using assessment factors. However, the available sediment tests should be

carefully evaluated. Special attention should be given to the pathways through which the test organisms are

exposed to the chemical and the test protocol should carefully be checked to determine whether feeding with

unspiked food has possibly reduced exposure via sediment ingestion. For assessing the toxicity of spiked

sediment it is necessary to address adequately all possible routes of exposure. Sediment organisms can be

exposed via their body surfaces to substances in solution in the overlying water and in the pore water and to

bound substances by direct contact or via ingestion of contaminated sediment particles. The route that is

most important is strongly influenced by species-specific feeding mechanisms and the behaviour of the

organism in, or on, the sediment. Test design parameters can have a bearing on the route of uptake of a

substance.

The PNECsed is derived from the lowest available NOEC/EC10 obtained in long-term tests by application of

the following assessment factors and is then expressed as mg/kg of dry sediment:

Table 10 Assessment factors for derivation of PNECsed

Available test result

One long-term test (NOEC or EC10) 100

Two long-term tests (NOEC or EC10) with species representing different living and feeding conditions

50

Three long-term tests (NOEC or EC10) with species representing different living and feeding conditions

10

Using the toxicity figures from the tests with spiked sediment on the reproduction of Chironomus, and

dividing by the appropriate assessment factor of 100, the calculated PNECsed is 1 mg/kg dry sediment for

paraquat dichloride.

PEClocal for sediment can be compared to the PNEC for sediment dwelling organisms. The concentration in

freshly deposited sediment is taken as the PEC for sediment, therefore, the properties of suspended matter

are used. The concentration in bulk sediment can be derived from the corresponding water body

concentration, assuming a thermodynamic partitioning equilibrium (see also Di Toro et al., 1991):

PEClocal sed= Kp susp−waterRHOsusp

×PEC localwater ×1000

Where

PEClocal water concentration in surface water during release episode based on GENEEC2 modelling (mg/L)

Ksusp-water suspended matter-water partitioning coefficient = 5.65 (m3/m3). Equation R.16-7 of REACH TGD

R16.

April 2016

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RHOsusp bulk density of suspended matter = 1150 (kg/m3) Equation R.16-16 of REACH TGD R16.

PEClocal sed predicted environmental concentration in sediment (mg/kg)

The worst-case scenario for the concentration expected to be measured in pore-water is the expected

concentration in the water column (i.e. 0.00895 mg/L, according to GENEEC2), therefore

PEClocal sed = 0.043 mg/kg sediment for paraquat.

The risk for sediment-dwelling organisms is assessed as the ratio PECsed/PNECsed. This ratio is 0.043 for

paraquat.

Conclusion for the sediment risk assessment:

Risks for sediment dwelling organisms due to paraquat are below the level of concern (LoC < 1).

6.7. Terrestrial risk assessment

For terrestrial organisms, Toxicity-Exposure Ratios (TERs) are used for earthworms and birds, Hazard

Quotient (HQ) are used for terrestrial invertebrates and Risk Quotient (RQ) for bees. This convention results

in concern arising if a risk quotient is less than the trigger value for earthworms and more than a trigger value

for terrestrial invertebrates. LOC developed by the European Union and adopted by the Staff allowing

determining whether a substance poses an environmental risk are provided in the Table 11.

Table 11 Levels of concern as adopted by the Staff

Level of Concern (LOC) Presumption

Earthworm/ Birds

Acute TER < 10 High risk

Chronic TER < 5 High risk

Threatened bird species



Threatened soil organisms species



Bees

Acute RQ oral/contact > 0.4 High risk

Chronic RQ > 1 High risk

Terrestrial invertebrates

April 2016

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HQ in-field/off-field ≥ 2 High risk

For more details about the different factors used for calculating TER and RQ refer to the relevant reference

documents listed in Table 5.

6.7.1. Earthworm risk assessment

Soil Predicted Environmental Concentration (PEC) determination

Both acute and reproductive earthworm tests are static tests where the test substance is applied to the

system only once at the beginning. Therefore the nominal dose levels in the test match initial concentrations

in the field and thus it is appropriate to use initial PEC values (no time-weighted averages) for the acute as

well as the long-term TER.

The concentration of active substance in the soil is calculated on the basis of the FOCUS (1997) document

‘Soil persistence models and EU registration’

PEC oneapplication(mg/kg soil)=applicationrate (kg a.i./ha)75kg soil

×100

Soil concentrations of the active ingredient are calculated by assuming the deposition would mix into the top

5 cm of soil, and this soil would have a bulk density of 1,500 kg/m3, i.e. the deposition expressed in mg/m2

would mix into 75 kg of soil.

In case of multiple applications, the following formula has to be used:

PECmultipleapplications=PEC oneapplication×(1−e−nki)(1−e−ki )

where:

n = number of applications

k = ln2/DT50 (day-1)

i = interval between two consecutive applications (days)

DT50 = half-life in soil (days) Use only DT50 values of lab test done at 10-20 oC and pH between 5 and 9.

e = 2.718 (constant)

When there are DT50 values of several soils use GENEEC2 formula for determining the relevant DT50 to be

used.

PEC calculation results are summarized for each scenario in

and Table 13.

Calculation of TERs

TERacute=LD50

Estimated EnvironmentalConcentration

TERlong− term= NOECEstimated EnvironmentalConcentration

Table 12 Acute in-field TER value for earthworms

April 2016

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ScenariosPEC (mg/kg soil)

LC50

(mg/kg soil)TER acute


Clover – 2 applications of 0.4 kg a.i./ha at 28 days interval

1.06

>1380

>1306

> 10 / Risk below concern

>100 / Risk below concern for threatened species

Non-crop land (streets, fence lines, industrial) - 4 applications of 1.5 kg a.i./ha at 28 days interval

7.77 >178

Forestry – 2 applications of 0.6 kg a.i./ha at 28 days interval

2.64 >523

Lucerne – 2 application of 0.6 kg a.i./ha at 28 days interval

1.58 >871

Barley grass control – 4 applications of 1.5 kg a.i./ha at 28 days interval

7.77 >178

Table 13 Acute off-field TER value for earthworms

ScenariosPEC (mg/kg soil)

LC50

(mg/kg soil)TER acute


Clover – 2 applications of 0.4 kg a.i./ha at 28 days interval 0.07

>1380

>19792


> 100 / Risk below concern for threatened species

Non-crop land (streets, fence lines) - 4 applications of 1.5 kg a.i./ha at 28 days interval

0.51 >2690

Forestry – 2 applications of 0.6 kg a.i./ha at 28 days interval

0.17 >7917

Lucerne – 2 application of 0.6 kg a.i./ha at 28 days interval

0.10 >13195

Barley grass control – 4 applications of 1.5 kg a.i./ha at 28 days interval 0.51 >2690

Conclusion for earthworm acute risk assessment

Risks were below the level of concern for off-field situations (outside the crop area) and for in-field (inside the

crop area) for earthworm species (including threatened species).

Conclusion for earthworm chronic risk assessment

April 2016

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There is no information about the chronic effects of paraquat dichloride to earthworms.

Conclusion for earthworm risk assessment

Risk to earthworms in-field (inside the crop area) and off-field (outside the crop area) were below the level of

concern.

6.7.2. Non-target plant risk assessment

Non target plants are non-crop plants located outside the treatment area.

Spray drift is considered the key exposure route for terrestrial plants located in the vicinity of the treated

area. The drift models produced by the BBA for the exposure assessment of aquatic organisms may be used

as a surrogate to cover the exposure assessment of terrestrial plants (Ganzelmeier et al., 1995, recently

updated by Rautmann et al., 2001).

Table 15 and Table 14 shows the drift expressed as percentage of the applied dose:

Table 15 Basic drift values for two applications

Ground deposition in % of the application rate (82nd percentiles)

Distance Field crops

Fruit crops Grapevine Hops

Vegetables Ornamentals

Small fruit

[m] Early late Early lateHeight

< 50 cm

Height

> 50 cm

1 2.38 2.38

3 25.53 12.13 2.53 7.23 17.73 7.23

5 0.47 16.87 6.81 1.09 3.22 9.60 0.47 3.22

10 0.24 9.61 3.11 0.35 1.07 4.18 0.24 1.07

15 0.16 5.61 1.58 0.18 0.56 2.57 0.16 0.56

20 0.12 2.59 0.9 0.11 0.36 1.21 0.12 0.36

30 0.08 0.87 0.4 0.06 0.19 0.38 0.08 0.19

Table 16 Basic drift values for four applications

April 2016

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In fruit, grapevine and hops for herbicides (but not for plant growth regulators) that are applied to the ground,

the column “field crops” is applicable.

It should be noted that these drift data have been generated with regard to intake into surface waters. In

particular, there is no vegetation barrier between the spray boom and the collector plates. In terrestrial

scenarios, however, horizontal and vertical interception by in-crop or off-crop vegetation as well as patchy

distribution is relevant (“three-dimensional-situation“); thus, when more realistic drift data become available

they should be used.

The initial assessment should be conducted for a distance of 1 m from the field edge for field crops,

vegetables or ground applications such as for herbicides, and 3 m for other crops. Risk mitigation measures

based on buffer zones within the crop area can also be quantified using the above table. In case of aerial

applications a deposition rate of 100 % is assumed as the default, however this figure may be refined by

applying appropriate models (e.g. AgDrift).

This tier is a quantitative risk assessment following a RQ approach. Both effects and exposure are

expressed in terms of application rate (g/ha). Effects data are represented by ER25 values from the studies,

also expressed as g/ha.

Table 17 TER value for non target plant – seedling emergence

April 2016

Ground deposition in % of the application rate (74th percentiles)

Distance Field crops

Fruit crops Grapevine Hops

Vegetables Ornamentals

Small fruit

[m] Early late Early lateHeight

< 50 cm

Height

> 50 cm

1 1.85 1.85

3 23.61 10.12 2.44 6.71 15.38 6.71

5 0.38 15.42 5.6 1.02 2.99 8.26 0.38 2.99

10 0.19 8.66 2.5 0.31 0.99 3.55 0.19 0.99

15 0.13 4.91 1.28 0.16 0.52 2.17 0.13 0.52

20 0.1 2.21 0.75 0.1 0.33 0.93 0.1 0.33

30 0.06 0.72 0.35 0.05 0.17 0.31 0.06 0.17

40 0.05 0.32 0.2 0.03 0.11 0.14 0.05 0.11

50 0.04 0.17 0.13 0.02 0.08 0.08 0.04 0.08

46

Scenarios Drift (%)

Exposure = drift x application rate (g ai/ha)

EC25

(g ai/ha)RQ


Clover 2.38 at 1 m9.52

950

0.01 < 1 / Below the level of concern

Non-crop land, fence lines, streets, industrial sites

1.85 at 1 m27.75

0.03< 1 / Below the level of concern

Forestry 25.53 at 1 m255.3 0.27 < 1 / Below the

level of concern

Lucerne 2.38 at 1 m14.28 0.02 < 1 / Below the

level of concern

Barley grass control

1.85 at 1 m 27.750.03 < 1 / Below the

level of concern

Table 18 TER value for non target plant – vegetative vigour

Scenarios Drift (%)

Exposure = drift x application rate (g/ha)

EC25

(g ai/ha)RQ


Clover 2.38 at 1 m 9.5215 0.63 < 1 / Risk below

concern

Non-crop land: fence lines, streets, industrial sites

1.85 at 1 m 27.75 1.85 >1 / High risk

Non-crop land: fence lines, streets, industrial sites

0.38 at 5 m 5.7

0.38< 1 / Risk below concern

Forestry 25.53 at 1 m 255.3 17.02 >1 / High risk



April 2016

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Forestry0.87 at 30 m 8.7

0.58 < 1 / Risk below concern

Lucerne 2.38 at 1 m 14.280.952 < 1 / Risk below

concern


1.85 at 1m 27.751.85

>1 / High risk


0.38 at 5 m 5.70.38 < 1 / Risk below

concern

The approach for threatened species is based on RQ and the NOEC from the same studies used previously.

Table 19 TER value for non target plant threatened species

Scenarios Drift (%)

Exposure = drift x application rate (g/ha)

NOEC(g ai/ha)

RQTrigger value / Presumption

Clover 2.38 at 1 m 9.52 4 2.38 > 1 / High risk

0.47 at 5 m 1.88 4 0.47 < 1 / Below concern

Fence lines, streets,

1.85 at 1 m 27.75 4 6.94 > 1 / High risk

0.38 at 5 m 5.7 4 1.425 > 1 / High risk


Forestry25.53 at 3 m 255.3 4 63.825 > 1 / High risk

16.87 at 5 m 168.7 4 42.175 > 1 / High risk

9.61 at 10 m 96.1 4 24.025 > 1 / High risk

5.61 at 15 m 56.1 4 14.025 > 1 / High risk

2.59 at 20 m 25.9 4 6.475 > 1 / High risk

0.87 at 30 m 8.7 4 2.175 > 1 / High risk

0.4 at 40 m 4.00 4 1.0 > 1 / High risk


April 2016

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Lucerne 2.38 at 1 m 14.28 4 3.57 > 1 / High risk



1.85 at 1 m 27.75 4 6.9375 > 1 / High risk

0.38 at 5 m 5.7 4 1.425 > 1 / High risk


Conclusion for non target plant risk assessment

The risks to seedling emergence were below the level of concern for all use scenarios. The risks to

vegetative vigour were below the level of concern for the uses on clover and Lucerne. However, high risks to

vegetative vigour of non-target plants were observed for the uses on non-crop land, forestry and barley grass

control. High risks were observed for threatened native terrestrial plants for all the uses.

The following downwind buffer zones must be observed in order to protect non-crop plants from

unacceptable levels of spray drift from the application of Para-Ken 250 Herbicide:

Non-crop situations: 5 meters

Forestry: 30 meters

Barley grass control: 5 meters

For the protection of threatened native terrestrial plants the following advisory downwind buffer zones must

be observed:

Clover: 5 meters

Non-crop situations: 10 meters

Forestry: 50 meters

Lucerne: 5 meters


6.7.3. Bird risk assessment

EPA uses EFSA’s Bird model and Excel© spreadsheets14 freely available on EFSA’s website to assess the

risks to birds.

The methodology calculates TERs where exposure is calculated as the dose that a bird will receive when

feeding in crops that have been sprayed. To avoid doing detailed evaluations for low risk scenarios,

assessments are performed in tiers of increasing complexity.

The steps for the acute assessment are:

14 different spreadsheets for spray application, granular application and seed treatment.For bait applications a spreadsheet with Daily Food Intake of NZ relevant species is available (Crocker et al., 2002).

April 2016

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Screening assessment

Tier I assessment

Higher tier assessment

The steps for the reproductive assessment are:


Phase-specific approach assessment


Progression to the next tier is only made if the threshold for concern is exceeded at the previous tier.

Screening risk assessment

Determination of levels of exposure

The principles underlying the exposure assessment are the same for all assessments other than

higher tier assessments in which more specific field exposure data may be used. The dose that a

bird receives (Daily Dietary Dose or DDD) is calculated from the application rate and a so-called

‘Shortcut value’ for the Residue per Unit Dose (RUD), reflecting the concentration on the bird’s food

and the quantity of food consumed. Quantities consumed are based on a bird’s energy

requirements, its energy assimilation and the energy content of its food (dry weight). Birds’ energy

requirements are based on an algorithm based on bodyweight and bird type (e.g. passerine/non-

passerine). For further details, refer to EFSA’ technical guidance document.

Both screening step assessments (acute and reproduction) select from 6 ‘indicator species’ each

applicable to a particular type of crop. They are not real species, but, by virtue of their size and

feeding habits, their exposure is considered worst-case for birds in a particular crop type. For

example, the representative species for orchards is described as a ‘small insectivorous bird’. It is

assumed that the relevant indicator species feeds only on contaminated food and the concentration

of pesticide on the food is not affected by the growth stage of the crop. Thus, the exposure

assessment is expressed as follows depending on the number of applications:

For acute test:

DDDoneapplication=application rate (kg/ha )×shortcut value

DDDmultiple applications=DDDone application×MAF90

For reproduction test:

DDD=applicationrate ( kg/ha )×shortcut value×TWA∗×MAFmean

*if toxic effect is considered to be caused by long-term exposure, use TWA = 0.53 (estimates time-weighted exposure over 21 days

assuming a default DT50 of 10 days).

The exposure to paraquat dichloride for bird acute dietary and reproductive screening assessments is shown

in the Table 20 and Error: Reference source not found respectively

April 2016

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The methodology calculates TERs where exposure is calculated as the dose that a bird will receive when

feeding in crops that have been sprayed. To avoid doing detailed evaluations for low risk scenarios,

assessments are performed in tiers of increasing complexity.

The steps for the acute assessment are:


Tier I assessment


The steps for the reproductive assessment are:


Phase-specific approach assessment


Progression to the next tier is only made if the threshold for concern is exceeded at the previous tier.

Screening risk assessment


The principles underlying the exposure assessment are the same for all assessments other than

higher tier assessments in which more specific field exposure data may be used. The dose that a

bird receives (Daily Dietary Dose or DDD) is calculated from the application rate and a so-called

‘Shortcut value’ for the Residue per Unit Dose (RUD), reflecting the concentration on the bird’s food

and the quantity of food consumed. Quantities consumed are based on a bird’s energy

requirements, its energy assimilation and the energy content of its food (dry weight). Birds’ energy

requirements are based on an algorithm based on bodyweight and bird type (e.g. passerine/non-

passerine). For further details, refer to EFSA’ technical guidance document.

Both screening step assessments (acute and reproduction) select from 6 ‘indicator species’ each

applicable to a particular type of crop. They are not real species, but, by virtue of their size and

feeding habits, their exposure is considered worst-case for birds in a particular crop type. For

example, the representative species for orchards is described as a ‘small insectivorous bird’. It is

assumed that the relevant indicator species feeds only on contaminated food and the concentration

of pesticide on the food is not affected by the growth stage of the crop. Thus, the exposure

assessment is expressed as follows depending on the number of applications:

For acute test:

DDDoneapplication=application rate (kg/ha )×shortcut value

DDDmultiple applications=DDDone application×MAF90

For reproduction test:

DDD=applicationrate ( kg/ha )×shortcut value×TWA∗×MAFmean

*if toxic effect is considered to be caused by long-term exposure, use TWA = 0.53 (estimates time-weighted exposure over 21 days

assuming a default DT50 of 10 days).

April 2016

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The exposure to paraquat dichloride for bird acute dietary and reproductive screening assessments is shown

in the Table 20.

Table 20 Exposure of birds for acute and reproduction screening assessment

Crop & BBCH class (where appropriate)1

Indicator species2

Application rate(kg/ha)

Short-cut value (90th%)3

MAF(90th %)4

No of applications

DDD

Clover (legume forage), 2 applications of 0.4 kg a.i./ha at 28 days interval

AcuteSmall omnivorous bird

0.4158.8

1.1 269.87

Long-term 64.8 15.11

Lucerne (legume forage), 2 applications of 0.6 kg a.i./ha at 28 days interval


0.6158.8

1.1 2104.81


Non selective weed control (legume forage), 4 applications of 0.6 kg a.i./ha at 28 days interval


0.6158.8 1.1

4104.81

Long-term 64.8 1.2 24.73

Forestry, 2 application of 1 kg a.i./ha at 28 days interval

AcuteSmall insectivorous bird

146.8

1.1 251.48


Non-crop land, 4 applications of 1.5 kg a.i./ha at 28 days interval

April 2016

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AcuteSmall granivorous bird

1.524.7 1.1

440.76

Long-term 11.4 1.2 10.88

1 EFSA, 2009, Table 5 p27





2 EFSA, 2009, Table 10 p34

3 EFSA, 2009, Table 10 p34

4 EFSA, 2009, Table 11 p34

5The exposure assessment of the reproduction assessment uses time-weighted average (TWA) exposure estimates over 1, 2, 3 or 21 days for different phases of the assessment. 1 day = 1.0; 2 days = 0.93; 3 days = 0.9; 21 days = 0.53

Note about TWA:

Table 21 Measures of exposure and toxicity used in the reproduction assessment

Breeding phaseTest endpoint used as surrogate

Short-term exposure

Long-term exposure

Pair formation/ breeding site selection

0.1 x LD5015 1 day DDD 21 day TWA DDD

Copulation and egg laying (5 days pre-laying through end of laying

NOAEL for the number of eggs laid per hen

1 day DDD 21 day TWA DDD

NOAEL for mean eggshell thickness


Incubation and hatching

0.1 x LD50 1 day DDD 21 day TWA DDD

NOAEL for proportion of viable eggs/eggs set/hen


15 From acute study.

April 2016

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NOAEL for proportion of hatchlings/viable eggs/hen

3 day TWA DDD 21 day TWA DDD

Juvenile growth and survival until fledging

0.1 x LD50 (extrinsic adult) 2 day TWA DDD 21 day TWA DDD

0.1 x LD50 (extrinsic juvenile)1 day DDD based on chick shortcut values of 3.8 and 22.716

21 day TWA DDD based on chick shortcut value of 3.8 and 22.73

NOAEL for proportion of 14 day old juveniles/number of hatchlings/hen


Post-fledging survival

0.1 x LD50

1 day DDD based on chick shortcut values of 3.8 and 22.73

21 day TWA DDD based on chick shortcut value of 3.8 and 22.73

NOAEL for 14 day old juvenile weights/hen


2 from acute study3 The two values are to account for ground and foliar dwelling arthropods with mean residue unit doses of 3.5 and 21 respectively. Assessments are made with both values. If TER are exceeded with either value, then an assessment based on the actual composition of the diet of relevant species.

Calculation of TERs

TER calculations are detailed in Table 22.

Table 22 TER values for acute dietary and reproductive risk assessment – Screening assessment

Birds type DDDToxicity endpoint value (mg/kg bw/d)

TER ratioTrigger value / Presumption

Clover - 2 applications of 0.4 kg a.i./ha at 28 days interval

Acute

Small omnivorous bird

69.87 LD50 = 35 0.5

< 10 / High risk

< 20 / High risk for threatened species

Long-term 15.11 NOEC = 2.8 0.2 < 5 / High risk

16 The two values are to account for ground and foliar dwelling arthropods with mean residue unit doses of 3.5 and 21 respectively. Assessments are made with both values. If TER are exceeded with either value, then an assessment based on the actual composition of the diet of relevant species.

April 2016

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Lucerne, 2 applications of 0.6 kg a.i./ha at 28 days interval

Acute


104.81 LD50 = 35 0.3

< 10 / High risk


Long-term 22.67 NOEC = 2.8 0.1

< 5 / High risk


Non selective weed control (pastures) - 4 applications of 0.6 kg a.i./ha at 28 days interval

Acute


104.81 LD50 = 35 0.3

< 10 / High risk



< 5 / High risk


Non selective weed control (pastures) - 4 applications of 1.5 kg a.i./ha at 28 days interval

Acute


LD50 = 35

< 10 / High risk


Long-term NOEC = 2.8

< 5 / High risk


Forestry, 2 applications of 1 kg a.i./ha at 28 days interval

Acute

Small insectivorous bird 51.48 LD50 = 35 0.7

< 10 / High risk


Long-term 10.61 NOEC = 2.8 0.3 < 5 / High risk

April 2016

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Non-crop land, 4 applications of 1.5 kg a.i./ha at 28 days interval

Acute

Small granivorous bird

40.76 LD50 = 35 0.9

< 10 / High risk



< 5 / High risk


Conclusion for bird risk assessment (screening)

Both acute and chronic screening risk assessment indicates high risks for birds (including threatened

species) for all scenarios of use. Therefore, the risk assessment has to be refined.

Tier 1 risk assessment

Tier 1 uses the same general approach as the screening assessment but requires more specific exposure

scenarios. The first step is to identify all general focal species listed in Table I.1 (Annex I) of the EFSA’

technical guidance document that are relevant for the intended use(s).

In the Tier 1 acute and phase-specific reproduction assessments exposure is calculated for generic focal

species’, applicable to particular crops. Such assessments refine the screening step assessments in that:

there are more bird ‘species’ (19) and crop options (21);

the growth stage of the crop is taken into account, affecting the residues on the feed;

more than one bird species may be considered for any one crop;

a bird’s diet can be calculated to include more than one food item.

The larger number of bird species, crop types and growth stages of the crops leads to a total of 138 RUD

shortcut options, each with a mean and 90th percentile value.


For each generic focal species the DDD is presented in Table 20.

April 2016

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Calculation of TERs (Tier 1)

The TER calculations in the frame of the Tier 1 assessment are detailed in the Table 23. The toxicity figures

are the same than those considered in the screening assessment.

Table 23 TER values for acute dietary and reproductive risk assessment - Tier 1 assessment

Crop & BBCH class (where appropriate)

Generic focal species1

Short-cut value (90th%)2


Clover – 2 applications of 0.4 kg a.i./ha at 28 days interval

Acute

BBCH >20Small insectivorous bird “wagtail”

25.2 3.2

< 10 / High Risk


Chronic 9.7 1.7

< 5 / High risk


Acute

BBCH > 50Small granivorous bird “finch”

7.4 10.7



Chronic 3.4 3.5

< 5 / High risk


Acute

BBCH > 50 Small omnivorous bird “lark”

7.2 11.7



Chronic 3.3 3.6

< 5 / High risk


April 2016

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Acute

BBCH 10-19Small insectivorous bird “wagtail”

26.8 3.0

< 10 / High risk


Chronic 11.3 1.1

< 5 / High risk


Acute

BBCH 10-49Small granivorous bird “finch”

24.7 3.2

< 10 / High Risk


Chronic 11.4 1.1

< 5 / High risk


AcuteBBCH 10-49 Small omnivorous bird

“lark”

24.0 3.3

< 10 / High Risk


Chronic 10.9 1.1

< 5 / High risk


Acute

BBCH 21-49, leaf development

Medium herbivorous/granivorous bird “pigeon”

55.6 1.4

< 10 / High risk


Chronic 22.7 0.5

< 5 / High risk


Lucerne (legume forage) – 2 applications of 0.6 kg a.i./ha at 28 days interval

Acute

BBCH >20

Small insectivorous bird “wagtail”

25.2 2.1

< 10 / High Risk


Chronic 9.7 0.8 < 5 / High risk

< 10 / High risk for threatened

April 2016

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species

Acute


7.4 7.2

< 10 / High Risk


Chronic 3.4 2.4

< 5 / High risk


Acute


7.2 7.4

< 10 / High Risk


Chronic 3.3 2.4

< 5 / High risk


Acute

BBCH 10-19Small insectivorous bird “wagtail”

26.8 2.0

< 10 / High Risk


Chronic 11.3 0.7

< 5 / High risk


Acute


24.7 2.1

< 10 / High Risk


Chronic 11.4 0.7

< 5 / High risk


Acute

BBCH 10-49

Small omnivorous bird “lark”

24.0 2.2

< 10 / High Risk



< 10 / High risk for threatened

April 2016

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species

AcuteBBCH 21-49, leaf development


55.6 1.0

< 10 / High Risk


Chronic 22.7 0.4

< 5 / High risk


Non selective weed control (barley grass) – 4 applications of 0.6 kg a.i./ha at 28 days interval

Acute

BBCH >20Small insectivorous bird “wagtail”

25.2 2.1

< 10 / High risk


Chronic 9.7 0.8

< 5 / High risk


Acute


7.4 7.2

< 10 / High risk


Chronic 3.4 2.2

< 5 / High risk


Acute


7.2 7.4

< 10 / High risk


Chronic 3.3 2.2

< 5 / High risk


Acute

BBCH 10-19 Small insectivorous bird “wagtail”

26.8 2.0

< 10 / High risk



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Acute


24.0 2.1

< 10 / High risk


Chronic 11.4 0.6

< 5 / High risk


Acute

BBCH 10-49

Small omnivorous bird “lark”

24.0 2.2

< 10 / High risk


Chronic 10.9 0.7

< 5 / High risk


AcuteBBCH 21-49, leaf development


55.6 1.0

< 10 / High risk


Chronic 12.5 0.6

< 5 / High risk


Forestry, 2 applications of 1 kg a.i./ha at 28 days interval

AcuteNot crop directed application all season

Small granivorous bird “finch”

27.4 1.4

< 10 / High risk


Chronic 12.6 0.4

< 5 / High risk


Acute

Not crop directed

Small insectivorous/worm feeding species “thrush”

7.4 4.3 < 10 / High risk


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application all season

Chronic 2.7 1.8

< 5 / High risk


Non-crop land (bare soil), 4 applications of 1.5 kg a.i./ha at 28 days interval

AcuteBBCH < 10

Small granivorous bird “finch”

24.7 0.9

< 10 / High risk


Chronic 11.4 0.3

< 5 / High risk


Acute

BBCH < 10 Small insectivorous bird “wagtail”

10.9 1.9

< 10 / High risk


Chronic 5.9 0.5

< 5 / High risk


Acute

BBCH < 10 Small omnivorous bird “lark”

17.4 1.2

< 10 / High risk


Chronic 8.2 0.4

< 5 / High risk


1 EFSA, 2009, Table I.1, Annex I

2 EFSA, 2009, Table I.1, Annex I

3 EFSA, 2009 - Table 11 p34

Conclusion for bird risk assessment (Tier 1)

For the uses on clover, there were high acute risks for all crops stages with the exception of application after

BBCH >50, where high risks were observed only for threatened bird species. There were high chronic risks

(including for threatened bird species) for all crop stages.

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For the uses on Lucerne there were high acute risks and high chronic risks for all crops stages.

For the uses on selective weed control (barley grass) at 0.6 kg a.i./ha there were high acute risks and high

chronic risks for all crops stages. The risks were high with this lower application rate, thus staff did not

modelled the application on barley at 1.5 kg a.i./ha, hence the risks are also deemed to be higher than the

level of concern.

For the uses on forestry there were high acute and high chronic risks.

For the uses on non-crop situations there were high acute and high chronic risks.

Refinement for bird risk assessment (Tier I)

Staff assessed separately the risk for birds following the application of Para-Ken 250 Herbicide in crop

(agricultural) use and non-crop situations (industrial, fence lines and stock yards) taking into account the

method of application of Para-Ken 250 Herbicide. It is recognized that the intended uses for high volume

broadcast on agricultural fields represent a higher potential risk to birds than the application using a

knapsack in non-crop situations.

Potential risk to birds from the application to non-crop situations

The application using knapsack around industrial sites, fence lines, stock yards to clean up weeds minimizes

residue deposition on foliage, thus this method of application is not expected to result in a significant food

contamination for birds. Therefore, the acute and chronic risk to birds resulting from the application of Para-

Ken 250 Herbicide using knapsack for spot treatment on non-crop situations is expected to be of low concern

for birds. The staff consider that it is appropriate to apply controls to ensure that the knapsack application is

carried out using coarse droplets to minimize spray drift to nearby foliage.

Potential acute risk to birds

The estimated acute TER exceed the level of concern following a broadcast spray application of Para-Ken

250 Herbicide to clover, Lucerne, barley grass control and forestry. The staff consider that due to the

environmental fate characteristics of paraquat dichloride, namely its strong adsorption to biological materials

leading to paraquat becoming less bioavailable, the risk to birds only exists shortly after application and

therefore once the applied paraquat has dried its risk is greatly reduced.

However, the staff consider that there are no adequate mitigation measures to control the potential acute

risks to bird’s species following the application of Para-Ken 250 Herbicide to clover, Lucerne, barley grass

control and forestry, thus these risks will remain unmanageable.

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Potential reproductive risk to birds

The estimated chronic TER exceed the level of concern for all bird types following a broadcast spray

application of Para-Ken 250 Herbicide to clover, Lucerne, barley grass control and forestry. The chronic risks

were estimated using the NOEC of 2.8 mg/kg bw/d selected from the reproduction study in the Mallard duck

based on the reduction in the percentage of viable eggs, eggs set, normality of hatching, and number of 14-

day old survival. The proposed use of Para-Ken 250 Herbicide will potential result in a risk to the

reproduction of birds. It was not possible to refine the risk assessment due to lack of appropriate higher tier

data (field studies) for the representative uses. Staff consider that the high reproductive risks to birds will

remain unmanageable.

Secondary poisoning

Paraquat dichloride is not bioaccumulative so no risk assessment for secondary poisoning is necessary for

this active ingredient.

6.7.4. Bee risk assessment

The risk to bees is assessed as follows:

Tier1- screening level risks

If a reasonable potential for exposure to the pesticide is identified, a screening-level risk assessment is

conducted. This step involves a comparison of Tier I estimated exposure concentrations (EECs) for contact

and oral routes of exposure to adults and larvae to Tier I acute and chronic levels of effects to individual bees

using laboratory-based studies. The conservatism of the Tier I screening-level risk quotient (RQ) value

results primarily from the model-generated exposure estimates that, while intended to represent

environmentally relevant exposure levels, are nonetheless considered high-end estimates. The resulting

acute and chronic RQ values are then compared to the corresponding level of concern (LOC) values for

acute and chronic risk (i.e., 0.4 and 1.0, respectively). Generally, if RQ values are below their respective

LOCs, a presumption of minimal risk is made, since the Tier I risk estimation methods are designed to be

conservative.

EEC are calculated as follows:

Measurement endpoint

Exposure route

Exposure estimate (EEC)*

Acute effect endpoint

Chronic effect endpoint#

Foliar application

Individual

survival (adults)Contact

Application rate (kg

ai/ha) x 2.4 µg ai/bee

Acute

contact LD50

None

Individual Diet Application rate (kg Acute oral Chronic adult oral

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survival (adults)ai/ha) x 98 µg ai/g x

0.292 g/dayLD50

NOAEL (effects to

survival or longevity)

Brood size and

successDiet

Application rate (kg

ai/ha) x 98 µg ai/g x

0.124 g/day

Larval LD50

Chronic larval oral

NOAEL (effects to adult

emergence, survival)

Soil treatment

Individual

survival (adults)Diet

Briggs EEC x 0.292

g/day

Acute oral

LD50

Chronic adult oral

NOAEL (effects to


Brood size and

successDiet

Briggs EEC x 0.124

g/dayLarval LD50

Chronic larval oral



Seed treatment&

Individual

survival (adults)Diet 1 µg ai/g x 0.292 g/day

Acute oral

LD50

Chronic adult oral

NOAEL (effects to


Brood size and

successDiet 1 µg ai/g x 0.124 g/day Larval LD50

Chronic larval oral



Tree trunk application**

Individual

survival (adults)Diet

µg ai applied to tree/g

foliage x 0.292 g/day

Acute oral

LD50

Chronic adult oral

NOAEL (effects to


Brood size and

successDiet

µg ai applied to tree/g

foliage x 0.124 g/dayLarval LD50

Chronic larval oral



* Based on food consumption rates for larvae (0.124 g/day) and adult (0.292 g/day) worker bees and concentration in pollen and nectar

** Note that concentration estimates for tree applications are specific to the type and age of the crop to which the chemical is applied.

# To calculate RQs for chronic effects, NOAEC can be used as the effect endpoint to compare with the exposure estimate in

concentration

& Assume that pesticide concentration in pollen and nectar of seed treated crops is 1 mg a.i./kg (1 μg a.i./g). • No adjustment is made

for application rate (Based on EPPO’s recommended screening value)

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RQ= EECLD50

Chronic RQ= EECNOAEL

Use scenarioApplication rate (kg ai/ha)

EEC (µg ai/bee)

Toxicity endpoint value (µg ai/bee)

RQTrigger value /Presumption

Clover

Acute / Adult bees - contact

0.4 0.96 9.26 0.10< 0.4 / No

concern

Acute / Adult bees - oral

0.4 11.45 9.06 1.26>0.4 / High risk

Non-crop situations: fence lines, streets, industrial sites


1.5 3.6 9.26 0.39< 0.4 / No

concern


1.5 42.94 9.06 4.74>0.4 / High risk

Forestry


1 2.4 9.26 0.26< 0.4 / No

concern


1 28.62 9.06 3.16>0.4 / High risk

Lucerne


0.6 1.44 9.26 0.16< 0.4 / No

concern


0.6 17.17 9.06 1.89>0.4 / High risk

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1.5 3.6 9.26 0.39< 0.4 / No

concern


1.5 42.94 9.06 4.74>0.4 / High risk

Acute effects on brood, acute oral effects and chronic effects on adults and brood

No assessment possible as no data provided on these toxicity endpoints

Conclusions for the bee risk assessment

Acute oral risks were below the level of concern for all use scenarios, but high contact risks for the uses on

barley grass and non-crop situations (industrial sites, stock yards). The following assumptions are made

regarding the potential exposure of bees to Para-Ken 250 Herbicide. Bees are not attracted to pine forests.

The application on Lucerne is during winter (when Lucerne is dormant) which will reduce the potential

exposure for bees. Likewise the application on non-crop situations will reduce the exposure to bees, which

are not likely to forage in industrial sites and/or around buildings. The staff consider that the application on

clover for seed production represent the highest potential exposure risk for bees. Therefore, the staff

consider that the Para-Ken 250 Herbicide must not be applied in clover crop intended for seed production.

6.8.5 Non-target arthropod risk assessment

There was no reliable data to conduct a quantitative risk assessment to non-target arthropods (LR50 and or

ER50). The staff conducted a search on relevant information about the effects of paraquat dichloride to non-

target arthropods but no data could be used to support a quantitative risk assessment. The staff consider

that the due to the properties and mode of action of paraquat dichloride the risks to non-target arthropods

can be considered below the level of concern.

6.8. Summary and conclusions of the ecological risk assessment

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6.8.1. Environmental fate and behaviour

Paraquat dichloride was shown to be very immobile in soil. Paraquat does not hydrolyse, does not

photodegrade in aqueous solutions, and is resistant to microbial degradation under aerobic and anaerobic

conditions. The primary route of environmental dissipation of paraquat is adsorption to biological materials

and soil clay particles. Due to the apparent adsorption strength of paraquat for soil clays, these bound

residues do not appear to be environmentally available. There was no desorption of paraquat from any of the

soils tested. Due to high biological toxicity to plants and animals prior to adsorption, paraquat is subject to

spray drift concerns. However, paraquat has extremely high adsorption coefficients, it is not expected to

volatilize once applied to the soil.

6.8.2. Ecotoxicology

The EPA staff assessed the potential risk to be triggered by the use of Para-Ken 250 Herbicide according to

the GAP table and draft label recommendations.

Aquatic organisms

Acute risks were below the level of concern for fish and aquatic invertebrates. High acute risks were

observed for algae fior use scenarios and high risk for thretaned aquatic plant species at application rates

higher than 1.0 kg paraquat dichloride per hectare. Chronic risks were below the level of concern for aquatic

invertebrates, but high chornic risks were observed for threatened species at 1.5 kg paraquat dichloride per

hectare. No chronic data was available for fish. Risks to algae cannot be mitigated using mitigation measures

such as buffer zones. The modelling with AgDrift calculated a buffer zone larger than 254 meters (largest

buffer zone possible to calculate using AgDrift). Therefore, the staff consider that the risks of Para-Ken 250

Herbicide to algae are not manageable.

Sediment organisms

Risk were below the level of concern for sediment dwelling organisms.

Soil organisms

Risks were below the level of concern for earthworms in field and outside the crop area, including for

threatened species.

Non-target plants

Risk were below the level of concern for seedling emergence for all proposed uses. However, high risks

were identified for vegetative vigour for the uses on non-crop situations, barley grass control and forestry.

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The following downwind buffer zones must be observed in order to protect non-crop plants from

unacceptable levels of spray drift from Para-Ken 250 Herbicide:

Non-crop situations (industrial sites, streets, etc.): 5 meters

Forestry: 30 meters


For the protection of threatened native terrestrial plants the following advisory downwind buffer zones must

be observed:

Clover: 5 meters

Non-crop application (industrial sites, streets, etc.): 10 meters

Forestry: 50 meters

Lucerne: 5 meters


Vertebrates

There were high acute and high chronic risks for all crops and bird types. There are no adequate mitigation

measures to protect birds from this potential risk.

Staff consider that for the applications of Para-Ken 250 Herbicide using knapsack for spot treatment in non-

crop situations, such as the removal of weeds in industrial sites and streets will represent a lower potential

risk for birds.Therefore this use is considered acceptable by staff.

Bees and non target arthropods

Acute oral risks to bees were below the level of concern. High contact risk to bees were observed for all use

scenarios. Staff consider that the potential exposure to clover crops represent the highest risk to

bees.Therefore, the staff consider that the Para-Ken 250 Herbicide must not be applied in clover crop

intended for seed production.

Staff consider that due to the mode of action and properties of paraquat dichloride the risks to non-target

arthropods can be considered below the level of concern.

Overall conclusion for the environmental risk assessment

Staff consider that the approval of Para-Ken 250 Herbicide as broadcast spray to clover, Lucerne, forestry

and barley grass control should be declined due to the unacceptable risks posed to algae and birds.

Staff consider that the application of Para-Ken 250 Herbicide as spot treatment (non wide-dispersive use) in

non-crop situations such as the application on streets and industrial sites the risks can be considered below

the level of concern for the environment.

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7. Controls

7.1. Physical hazards controls

Apply the Approved Handler Controls (AH1, F4): Yes No

Apply the Tracking control (TR1): Yes No

7.2. Toxicity controls

Exposure Thresholds

Table 5 Active ingredient(s) exposure thresholds

Active Ingredient(s)

Acceptable Daily Exposure (ADE) – mg/kg bw/d

Potential Daily Exposure (PDE) – mg/kg bw/d

Tolerable Exposure Limit (TEL)mg/L (water)mg/kg (soil)mg/m3 (air)

Workplace Exposure Standard (WES17)

Paraquat dichloride Not set at this time Not set at this time Not set at this time

WorkSafe New Zealand has not set a WES for paraquat dichloride .

Table 6 Other component(s) exposure thresholds

Other component(s) WES Component D WorkSafe New Zealand has set a WES value for

Component D of Para-Ken 250 Herbicide and Staff consider this value to be applicable to Para-Ken 250 Herbicide

Apply the Approved Handler Controls - Highly Toxic Substances (AH1, T6): Yes No

Apply the Tracking Control - Highly Toxic Substances (TR1): Yes No

Other toxicity controls

Based on the human health risk assessment Staff were not able to identify any controls that would

sufficiently ensure that exposures are below acceptable levels.

7.3. Ecotoxicity controls

Table 7 Active ingredient(s) maximum application rates

17 http://www.business.govt.nz/worksafe/information-guidance/all-guidance-items/workplace-exposure-standards-and-biological-exposure-indices/workplace-exposure-standards-and-biological-indices-2013.pdf

April 2016

http://www.business.govt.nz/worksafe/information-guidance/all-guidance-items/workplace-exposure-standards-and-biological-exposure-indices/workplace-exposure-standards-and-biological-indices-2013.pdf

http://www.business.govt.nz/worksafe/information-guidance/all-guidance-items/workplace-exposure-standards-and-biological-exposure-indices/workplace-exposure-standards-and-biological-indices-2013.pdf

71

Active component Maximum application rate18 (control code E2)Paraquat dichloride 1.5 kg a.i./ha, 4 applications at 28 days interval

Apply the Approved Handler Controls- Highly ecotoxic substances (AH1, E7): Yes No

Apply the Tracking control- Highly ecotoxic substances (TR1): Yes No

Other ecotoxicity controls

Additional controls, under section 77A, are set for the application of of Para-Ken 250 Herbicide as spot

treatment using knapsack:

This substance must not be applied onto or into water.

The knapsack must have nozzles equipped to release coarse droplets to prevent spray drift

7.4. Mixture hazard classification calculations for identification controls

Table 8 Cut-off values triggering HSNO classification and requiring identification controls on the label and/or Safety Data Sheet (SDS)

HSNO Classification Cut-off for label (% w/w) Cut-off for SDS (% w/w)6.1A, B, C, D Any % of component that would

independently of any other component cause the product to classify

Any % that causes the product to classify

6.1E aspiration

(required on the basis of §77a)

Any % of component that would independently of any other component cause the product to classify

Any % of component that would independently of any other component cause the product to classify

8.2, 8.3 Any % that causes the product to classify as 8.2 and/or 8.3

Any % that causes the product to classify

6.5A, 6.5B, 6.6A, 6.7A 0.1 0.1

6.6B 1 1

6.7B 1 0.1

6.8A, 6.8C 0.3 0.1

6.8B 3 0.1

6.9A, 6.9B 10 1

Table 9 List of components requiring identification

Label SDSParaquat dichloride Paraquat dichloride

18 These regulations relate to the requirement to set an application rate for a class 9 substance that is to be sprayed or applied to an area of land (or air or water) and for which an EEL has been set.

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References

Novis P (2015) New Zealand Freshwater and Brackish Diatom Types.

http://www.landcareresearch.co.nz/resources/identification/algae/diatoms

SANCO (2003) Review Report for the active substance paraquat. October 3, 2003.

United States Environmental Protection Agency (1997) Registration Eligibility Document (RED). Paraquat

Dichloride. August 1997.

April 2016

http://www.landcareresearch.co.nz/resources/identification/algae/diatoms

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