mirrico seminar, kazan, september 2011 paul wood and anna vatsurina
TRANSCRIPT
Mirrico Seminar, Kazan, September 2011Paul Wood and Anna Vatsurina
Outline
Learnings from an incident Review Risk, Hazard and Exposure Exposure issues Examples of how Dow Microbial Control, controls exposure to
biocides Packaging Labelling Safe Removal Transport Lab Safety Storage
Dosing Suggestions Conclusions
Everyone Learns from an Incident
Biocides are not dangerous when handled correctly
Chemical Handling: Level of Risk
• Hazard Type or Consequence of Exposure
Corrosive = will cause burns (contact may not be detected immediately)
Toxic = a poison
Respiratory irritant = like household bleach or ammonia
Skin sensitizers = cause “skin allergy”
• Exposure Potential or Likelihood of Event
How much product ?
Probability of an exposure ?
Two factors to determine the risk when handling a chemical
Hazard x Exposure Potential = Risk
Level of Risk
Priority in hazard management reduces the exposure potential
Hazard = HIGH LOW LOW
Hazard = HIGH HIGH HIGH
SafeEthanol =x
UnsafeEthanol =x
There are many routes to exposure
Exposure Potential
Inhalation Skin Ingestion
How do we come into contact with a chemical ?
Types of Workplace Exposure
Gloves left lying on the floor
Water collecting on top of a drum
Contaminated cleaning cloth left in a bin
Opening, moving, connecting / disconnecting,
emptying apparently “Empty” drums
Containers used for hazardous materials without
labels
Cleaning / repair of contaminated installations
Door handles / Doors opened by someone wearing
gloves
Exposure to biocide residues
Types of Workplace Exposure
Spills from damaged packaging, or pipe work
Dosing from drums, or pails manually
Decanting from drums, or pails into smaller vessels
Using samples
Collecting samples from the production process Taking samples for Quality Control of raw materials
Samples shipped to customers
Handling samples in the lab.
Exposure to liquid biocides
Exposure Control
Perform a hazard- and safety analysis of the intended task according to your internal rules ( EHS review )
Follow the recommendations on MSDS* and Labels
Installations and tools you intend to use for the planned task
PPE (Personal Protective Equipment): type and control intervals
Appropriate ventilation of the working place / area
Safety installations: Safety Showers / Eye rinsing stations
Industrial Hygiene / Cleanliness and Housekeeping
Working Instruction
Spill-/Leakage Handling
Emergency Procedures
Training !!!
If there is the potential for exposure
Biocide Packaging
Containers Have to be UN approved
3H1/Y1.4/150/** GB/3380
Stringent testing
Drop tested
Are fitted with tamper evident
seals for security reasons
Are palletised to prevent damage
The number of drums are limited
on a pallet to prevent overhang
and restrict weight
Packaging ergonomics
Packaging has to be designed to be safe
On Site Signs & Labelling
Signs placed around the workplace inform
operators on which and when personal
protective equipment should be worn in
specific areas
In addition use educational posters as part
of an on-going safety education program
Product labelling is one source of information but there are others…
Personal Protective Equipment ( PPE )
• Helmet
• Goggles• Suit• Gloves
• Rubber Overshoes
Burns caused by not wearing gloves
Burns caused by improper removal of gloves
To avoid mishandling and accidents
Always ensure samples are clearly labelled
Warning symbols are visible
Store products in clearly labelled cabinets
To prevent exposure during use
Handle biocides in a fume cupboard
Make sure lab technicians wear the correct protective clothing:
Gloves
Goggles
Ensure the area where biocides are handled is kept clean
Lab Safety
Warehouse Storage
Store biocides safely
• To maximise the safety of people Training Keep pedestrians separate from product Safety barriers around offices Special bins for hazardous waste Ventilate warehouse
• To prevent blind corners, or falling containers Restrict pallet height
To avoid mishandling
Use painted areas
Good lighting
Suggestions
Be proactive
Review the MSDS and label warnings
Do a safety review of the job
Have a written procedure and follow it
Evaluate and inspect the equipment to be used
Inspect your Personal Protective Equipment
Have the spill deactivation kit equipment and chemicals in place before an incident occurs!
18
Why use biocides ?
Essential To:
Maintain Efficient Heat Exchange Prevent Corrosion Prevent Plugging of Orifices Prevent Potential Health Concerns Maintain Aesthetic Appearance
19
Why use biocides ?
Microbes can be:
algae if light reaches the collection basin
aerobic bacteria
anaerobic bacteria (SRB’s)
Moulds and yeast
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Bio-films
Microbes can attach to surfaces and produce slime
impairs the heat transfer
induces microbial corrosion (MIC)
clogs filters, screens, casings and nozzles
potentially harbours Legionella pneumophila
Biofouling Control – Biofilm Issue
A biofilm is a layer of slime that is produced by microbes after they attach to a surface Biofilms serve to protect the microbial community that is
underneath it Corrosion and H2S production result from the growth of microbes
within a biofilm Removing biofilm is more difficult than preventing the formation of a
biofilm
Stage 1Conditioning
Layer
Stage 2Bacterial
Attachment
Stage 3Slime Formation (EPS Production)
Stage 4Slime
Thickening
Stage 5Slime
Detachment
Examples of “Patchiness” in Bio-films on 316 Stainless Steel
23
Review of the active ingredients used in indistrial water cycles
24
Oxidisers
Cl2, HOCl, Br2, HoBr,
Chloramaines ; ClO2, H2O2 / Peracetic acid
Corrosive Very fast acting Effect is short-lived – no permanance Generate high levels of AoX ( adsorbable organic
halides )
1, 5-pentanedial
OO
H H
Glutaraldehyde
Quick kill (1-3 hours) under alkaline conditions (pH 7-9)
Broad spectrum efficacy Highly effective against SRB, biofilm, and Legionella Readily biodegradable at concentrations < 5-ppm Compatible with dispersants, surfactants and most
WT chemicals, including CMIT/MIT Compatible with halogens and other WT additives Does not contain or release formaldehyde Kills via cross-linking proteins in cell wall
Glutaraldehyde Features
Weak efficacy versus fungi and algae Stability with ammonia (NH3) and alkaline pH
De-activated by bisulphites Polymerises under alkaline and high temperature
conditions (haziness / yellowing) Evaporation (volatilization) potential increases with
temperature and /or aeration
Glutaraldehyde Limitations
DBNPA
2,2-dibromo-3-nitrilopropionamide
CC
C
N
BrBr
O
N
H
H
Registered ApplicationsCooling Water (Re-circulating / Once-through / Open / Closed)Retort Systems, PasteurizersReverse Osmosis MembranesAir Scrubbers and WashersPaper MillsAdditives/Mineral SlurriesEnhanced Oil RecoveryPublicly Owned Treatment Works
DBNPA Features
Extremely fast acting (15 - 60 min) Broad spectrum efficacy Highly effective against biofilm and Legionella Effective at low dose levels Easy to dose liquid Non-corrosive at in-use concentration Low environmental impact Short half-life at more alkaline pH’s Kills via reactions with sulphydryls and
disruption of respiration and metabolism
DBNPA Limitations
Liquid product shelf life is limited (6 months) Weak versus fungi and algae Low solubility in water Incompatible with strong nucleophiles and
reducing agents Not UV stable Occasionally referred to as an oxidizer
THPS
P
HOH2C
CH2OH
HOH2C
CH2OH
+SO4 2-
2
tetrakis(hydroxymethyl) phosphonium sulphate
Feature Benefit
Fast acting, broad spectrum Control of wide range of microorganisms
Active against SRB; Algae and Legionella
Useful for a wide range of industrial applications
Dissolves FeS Reduces FeS related problems such as fouling of equipment
Low dosages Cost effective
Favourable aquatic toxicity Very low impact on ecologyand minimal effect on environment
Degradation to inert components
Non-foaming Easy to use in high-flow systems
No organic solvents Safety in use; completely water miscible
THPS
THPS Limitations
Known to release formaldehyde rapidly (25% of total dose)
Cationic properties react with anionic inhibitors
Not compatible with oxidizing biocides
Unstable at high pH
Issues with use of THPS in high calcium waters
Registered Applications Recirculating Cooling Water (Open and Closed) Air Washers & Industrial Scrubbing Industrial Process Water Brewery Pasteurizers and Can Warmers Industrial Wastewater RO / UF Membranes (non-medical; non-potable) Pulp and Paper Slimicide Additive and Slurry Preservation
CMIT / MIT
CMIT / MIT Features
Broad-spectrum activity Provides control over bacteria, algae, and fungi with no performance gaps. Effective vs Legionella, SRB, and biofilm
Fast Acting Provides immediate control circa 10 minutes
Stable over a wide range of pH (<9) and temperature (<40° C)
Effective under conditions typically encountered in most processes
Clear, water soluble, liquid Fully water soluble at use levels and easy to dose
Broad chemical compatibility Compatible with most cooling water and papermill additives and biocides
Low use rates Cost effective
Biodegradable and does not generate AOX or formaldehyde
Environmentally friendly
Product Feature Customer Benefit
Poor stability above pH 9 and >40º C Poor stability with nucleophiles and reducing agents
(sulphides, sulphites, amines,) Perceived weakness versus SRB Slow killing Safe handling concerns / sensitization / burns New solid version will address safety issues
CMIT / MIT Limitations
Oxidizing DBNPA Glutaraldehyde THPS CMIT/MIT
Products Cl2/HOCl
BCDMHClO2
AM 7287Sump Buddy
UCARCIDE 24, 50 AQUCAR THPS 75
KATHON WT
Rate of kill Very very fast
Very fast Fast Fast Slow
Persistence No No Yes Yes Yes
Thermal resistance Excellent Medium Excellent Good Medium
pH range 4 - 7.5 Up to 8.5 Up to 9.5 Up to 9.5 2 to 9
Organisms A,B,F A, B, F biofilm ++
A, B, (F) biofilm +++
A, B B, F, Y, M
Biodegradability n.a. Fast (readily biodeg.)
Very fast (readily biodeg.)
Inherently biodegr.
Inherently biodegr.
FA release No No No Yes No
Comparison of Biocides for WT
Actives Used for Industrial Water Treatment and Paper
Biocide Cooling Water
Air Wash. RO / UF PaperSlimicide
Glutaraldehyde x x x x
DBNPA x x x x
CTAC x
CMIT/MIT x x x x
DCOIT x x
Spasibo