Practical Considerations For Practical Considerations For Air Monitoring With Emphasis Air Monitoring With Emphasis On Direct Reading Real Time On Direct Reading Real Time

MonitorsMonitors

Occupational Hygiene Association Occupational Hygiene Association of Ontario Spring Symposium of Ontario Spring Symposium

By: Jamie Prince B.Sc, OHST, ROHTBy: Jamie Prince B.Sc, OHST, ROHTGeneral Motors of Canada LimitedGeneral Motors of Canada Limited

OUTLINEOUTLINE

• What Can Be MeasuredWhat Can Be Measured

• Sampling Strategies Sampling Strategies

• Types of Sampling EquipmentTypes of Sampling Equipment

• Examples of Real Time MonitorsExamples of Real Time Monitors

• Advantages/Disadvantages of Real Time Advantages/Disadvantages of Real Time Air MonitoringAir Monitoring

• Real Time Air Monitoring ExamplesReal Time Air Monitoring Examples

• ConclusionsConclusions

PHYSICAL/CHEMICALPHYSICAL/CHEMICAL STATESSTATES

• solids: solids: dust, fibres, fume, smokedust, fibres, fume, smoke

• liquids: liquids: mist, aerosolsmist, aerosols

• gases: gases: vapoursvapoursremember: remember:

gasgas

solidsolid liquidliquid

7 TYPES OF CONTAMINANTS7 TYPES OF CONTAMINANTS

• DustsDusts- airborne solid particles ranging in size - airborne solid particles ranging in size from 0.1 to 25 microns. Particles 5 microns and from 0.1 to 25 microns. Particles 5 microns and larger don’t usually remain airborne to present an larger don’t usually remain airborne to present an inhalation hazard.inhalation hazard.

• FumesFumes- material from a volatized solid - material from a volatized solid condenses in cool air. Size of the particulate condenses in cool air. Size of the particulate formed are less than 1 micron in diameter.formed are less than 1 micron in diameter.

• SmokeSmoke- from incomplete combustion of carbon - from incomplete combustion of carbon containing materials, its made up of carbon or containing materials, its made up of carbon or soot particles. Can vary in size.soot particles. Can vary in size.

7 TYPES OF CONTAMINANTS7 TYPES OF CONTAMINANTS • AerosolsAerosols- liquid droplets or solid particles, - liquid droplets or solid particles,

fine enough to remain dispersed in air for a fine enough to remain dispersed in air for a prolonged periodprolonged period..

• MistsMists-- liquid droplets suspended in the liquid droplets suspended in the atmosphere. atmosphere.

• GasesGases- - are “formless fluids” that expand to are “formless fluids” that expand to fill the space or enclosure in which they are fill the space or enclosure in which they are confined.confined.

• VapoursVapours- - are the volatile form of are the volatile form of substances that are usually in the liquid or substances that are usually in the liquid or solid state at room temperature and pressure. solid state at room temperature and pressure.

PHYSICAL/CHEMICAL STATESPHYSICAL/CHEMICAL STATES

• size: respirable (less than 10 μm)size: respirable (less than 10 μm)fibres (length & fibres (length &

diameter)diameter)• chemical charge (Crchemical charge (CrIIIIII or Cr or CrVIVI))• solubility (Ni)solubility (Ni)• crystal structure (silica, talc)crystal structure (silica, talc)• fibrous or non-fibrousfibrous or non-fibrous• polar/non polarpolar/non polar

MIXTURESMIXTURES• decomposition products (smoke, etc.) decomposition products (smoke, etc.)

often have thousands of componentsoften have thousands of components

• sometimes “marker” substances sometimes “marker” substances measured (like CO) measured (like CO) – if a “marker” is used, the TWAEV for the if a “marker” is used, the TWAEV for the

marker substance is marker substance is notnot applicable! applicable!

• can be sampled as a group (e.g. VOC’s), can be sampled as a group (e.g. VOC’s), but usually no TWAEVbut usually no TWAEV

MIXTURESMIXTURES• Measuring each of the thousands of constituents in Measuring each of the thousands of constituents in

decomposition products would be a chemist’s decomposition products would be a chemist’s nightmarenightmare

• almost all of the constituents will be well below almost all of the constituents will be well below individual TWAEV’sindividual TWAEV’s

• even summing the TWAEV’s seldom exceeds even summing the TWAEV’s seldom exceeds summed TWAEV criteriasummed TWAEV criteria

• Combinations:Combinations:– Vapour condensing on particlesVapour condensing on particles– vapour absorbed by liquid aerosolsvapour absorbed by liquid aerosols– liquid evaporating from aerosol/particulateliquid evaporating from aerosol/particulate

SO YOU WANT TO SAMPLE?SO YOU WANT TO SAMPLE?Then answer the 5 W’s and 3 H’s:Then answer the 5 W’s and 3 H’s:

• Why?Why?

• What?What?

• Who? Who?

• When?When?

• Where?Where?

• How?How?

• How many?How many?

• How long?How long?

SAMPLING STRATEGIESSAMPLING STRATEGIESWHY?WHY?• Reactive Sampling, Source Identification -Reactive Sampling, Source Identification -

Employee Concerns: What’s causing the Employee Concerns: What’s causing the complaints/symptomscomplaints/symptoms

• Compliance Sampling, New Process, DSRCompliance Sampling, New Process, DSR

• Proactive SamplingProactive Sampling

• Engineering Control VerificationEngineering Control Verification

ALTERNATIVES TO ALTERNATIVES TO SAMPLINGSAMPLING

• Eliminate the sourceEliminate the source

• Add engineering controlsAdd engineering controls

• Use odour and irritation thresholdsUse odour and irritation thresholds

• Hazard mapping, use employee Hazard mapping, use employee experiencesexperiences

• Computer modellingComputer modelling

EXPOSURE CONTINUUMEXPOSURE CONTINUUM source > path > exposure > uptake > targetsource > path > exposure > uptake > target

Try to move as far to the left of the Try to move as far to the left of the continuum as possible (continuum as possible (preventionprevention!)!)

• Source: substitution, enclosureSource: substitution, enclosure

• Path: ventilation evaluation, work practicesPath: ventilation evaluation, work practices

• Exposure: IH measurementsExposure: IH measurements

• Uptake: symptoms, blood/urine samplesUptake: symptoms, blood/urine samples

• Target: clinical tests, diagnosisTarget: clinical tests, diagnosis

SAMPLING STRATEGIESSAMPLING STRATEGIESWHAT?WHAT?• Type: bulk, area, personalType: bulk, area, personal• Time: short term (CEV, STEV), long term Time: short term (CEV, STEV), long term

(TWAEV), sequential, grab (series)(TWAEV), sequential, grab (series)• Method: “quick and dirty” (colourimetric), Method: “quick and dirty” (colourimetric),

direct reading real time, official (NIOSH direct reading real time, official (NIOSH etc)etc)

• Conditions: worst case, random (unbiased), Conditions: worst case, random (unbiased), staged (simulated), regular work shift.staged (simulated), regular work shift.

• Number: “one shot”, statistically Number: “one shot”, statistically representative, cumulative exposuresrepresentative, cumulative exposures

WHO WHEN WHERE?WHO WHEN WHERE?What workplace variables cause exposures What workplace variables cause exposures

to go up or down?to go up or down?

• weather (season, temp, humidity, wind)weather (season, temp, humidity, wind)

• doors & windows, cross draftsdoors & windows, cross drafts

• shift, production schedules, ratesshift, production schedules, rates

• ventilation in other areas of plantventilation in other areas of plant

• housekeeping, traffic, activity levelshousekeeping, traffic, activity levels

• individual work practices, man cooling fansindividual work practices, man cooling fans

SAMPLING CONDITIONSSAMPLING CONDITIONS

• make sure important variables are make sure important variables are addressed in strategyaddressed in strategy

• keep records of conditions during keep records of conditions during samplingsampling

•start & finish timesstart & finish times

•production levelsproduction levels

•ventilation (doors, windows, local & ventilation (doors, windows, local & general) general)

•workers’ opinion if sampling period is workers’ opinion if sampling period is representative of better than average, representative of better than average, normal, worse than normal conditionsnormal, worse than normal conditions

HOW?HOW?TYPES OF SAMPLING TYPES OF SAMPLING EQUIPMENTEQUIPMENT• Colourimetric (Draeger tubes, dositubes)Colourimetric (Draeger tubes, dositubes)

• Passive Absorption Badges: Organic Passive Absorption Badges: Organic Vapours, formaldehyde, other gases and Vapours, formaldehyde, other gases and vapoursvapours

• Pumps:Pumps:– filter cassettes (with or without cyclones or filter cassettes (with or without cyclones or

impacters) for particulates, aerosols and impacters) for particulates, aerosols and fibersfibers

– sorbent tubes, (charcoal, silica gel, sorbent tubes, (charcoal, silica gel, specialized) for gases and vapours.specialized) for gases and vapours.

– Liquid samplers (impingers) for vapours, Liquid samplers (impingers) for vapours, particulates, aerosolsparticulates, aerosols

TYPES OF REAL TIME AIR TYPES OF REAL TIME AIR MONITORSMONITORS

• ParticulatesParticulates– Total particulates/aerosols (data-logging): Total particulates/aerosols (data-logging):

DataRam, Dust TrakDataRam, Dust Trak– Fibers: FAM (Fibrous Aerosol Monitor) asbestosFibers: FAM (Fibrous Aerosol Monitor) asbestos

• Gases/VapoursGases/Vapours– FID and PID (data-logging) for organic compoundsFID and PID (data-logging) for organic compounds– Inorganic gases and vapours, CO, CO2, mercury, Inorganic gases and vapours, CO, CO2, mercury,

H2SH2S– Paper Tape for isocyanates Paper Tape for isocyanates – Lead Niton X-ray fluorescenceLead Niton X-ray fluorescence– Indoor Air Quality multi-function monitorsIndoor Air Quality multi-function monitors

HOW MANY?HOW MANY?

How Many Samples Do You Need To Take?How Many Samples Do You Need To Take?

• Compliance sampling needs a large number of Compliance sampling needs a large number of representative samples over a long period of timerepresentative samples over a long period of time– use traditional sampling methodsuse traditional sampling methods

• Worst case sampling may require only a few Worst case sampling may require only a few samples over a short periodsamples over a short period– direct reading or real time may be requireddirect reading or real time may be required

• Type of hazard may determine how many and for Type of hazard may determine how many and for how longhow long– peak exposures, length of peaks, short term peak exposures, length of peaks, short term

acute hazards, does it come and goacute hazards, does it come and go

HOW LONG?HOW LONG?

• Lowest detectable quantityLowest detectable quantity

• Don’t overload sample mediaDon’t overload sample media

• Short sample period for acute hazardsShort sample period for acute hazards

• Chronic hazard may need full shiftChronic hazard may need full shift

• Peaks need data-logging, real time direct Peaks need data-logging, real time direct reading or short term sequential samplesreading or short term sequential samples

• IDLH for confined space needs IDLH for confined space needs immediate answerimmediate answer

• Leak detection needs direct readingLeak detection needs direct reading

DISADVANTAGES OF LONG DISADVANTAGES OF LONG TERM SAMPLINGTERM SAMPLING

• Analysis and Feedback time too long, chance Analysis and Feedback time too long, chance of exposing employees to hazardous levelsof exposing employees to hazardous levels

• Inability to answer employee concerns, Inability to answer employee concerns, continued refusal to work, loss of productioncontinued refusal to work, loss of production

• Inability to Determine STEL and Ceiling Inability to Determine STEL and Ceiling Values, ie. short term maintenance jobsValues, ie. short term maintenance jobs

• 90% of all long term samples were less than 90% of all long term samples were less than 10% of any EEG, however employees 10% of any EEG, however employees continued to complain, especially of irritationcontinued to complain, especially of irritation

• Ineffective use of Hygienist’s timeIneffective use of Hygienist’s time

ADVANTAGES OF REAL TIMEADVANTAGES OF REAL TIME

• Instant feedback of exposure levels to Instant feedback of exposure levels to hygienist and employees, ease of mindhygienist and employees, ease of mind

• Employee trust, can see exposure on Employee trust, can see exposure on metermeter

• Ability to determine time vs concentration Ability to determine time vs concentration with data-logging instrumentswith data-logging instruments

• Ability to determine STEL and Ceiling Ability to determine STEL and Ceiling ValuesValues

• Quick determination of how changes to Quick determination of how changes to process or engineering controls affect process or engineering controls affect employee exposuresemployee exposures

• More efficient use of hygienist’s timeMore efficient use of hygienist’s time

DISADVANTAGES OF REAL DISADVANTAGES OF REAL TIME AIR MONITORSTIME AIR MONITORS• Specificity of monitorSpecificity of monitor• Interpretation of results, employee Interpretation of results, employee

misunderstandingmisunderstanding• Interferences, CO, TOHC’s , Water VapourInterferences, CO, TOHC’s , Water Vapour• Method may not be accepted by GovernmentMethod may not be accepted by Government• Difficult or unable to CalibrateDifficult or unable to Calibrate• Assuming dust monitor detects all particle Assuming dust monitor detects all particle

sizes equally wellsizes equally well• Cannot usually be used for compliance Cannot usually be used for compliance

sampling, lead, isocyanates, silica, asbestos sampling, lead, isocyanates, silica, asbestos • AccuracyAccuracy

REAL TIME INSTRUMENTSREAL TIME INSTRUMENTS

• CENTURY SYSTEMS OVA TOHCCENTURY SYSTEMS OVA TOHC• RIKIN 411 CO2 MONITORRIKIN 411 CO2 MONITOR• DRAEGER CO DATALOGGERDRAEGER CO DATALOGGER• MINIRAM, TPMINIRAM, TP• DATARAM TP DATALOGGERDATARAM TP DATALOGGER• REUTER STOKES WIBGETREUTER STOKES WIBGET• GMD AUTOSTEP (CAP) ISOCYANATESGMD AUTOSTEP (CAP) ISOCYANATES• TOXIRAE PID TOHC’STOXIRAE PID TOHC’S• SOLOMAT IAQ MONITORSOLOMAT IAQ MONITOR

SEALER REMOVAL SOLVENTSEALER REMOVAL SOLVENTINSTRUMENT- CENTURY SYSTEMS OVAINSTRUMENT- CENTURY SYSTEMS OVA• Sealer removal from car in open areaSealer removal from car in open area• which solvent had lowest exposure levelswhich solvent had lowest exposure levels• FP and VP not usefulFP and VP not useful

– solvent 1- 35-40 ppm peaks TWA 100 ppmsolvent 1- 35-40 ppm peaks TWA 100 ppm– solvent 2--50-60 ppm peaks TWA 100 ppmsolvent 2--50-60 ppm peaks TWA 100 ppm– solvent 3--35-40 ppm peaks TWA 100 ppmsolvent 3--35-40 ppm peaks TWA 100 ppm– solvent 4--20-30 ppm peaks TWA 100 ppmsolvent 4--20-30 ppm peaks TWA 100 ppm– solvent 5---85-100 ppm peaks TWA 400 ppmsolvent 5---85-100 ppm peaks TWA 400 ppm

• Solvent 4 or 5 recommended Solvent 4 or 5 recommended • Solvent 4 chosen because of higher FPSolvent 4 chosen because of higher FP

FLAT TOP COFLAT TOP COINSTRUMENT- DRAEGER CO DATALOGGERINSTRUMENT- DRAEGER CO DATALOGGER• CO buildup suspected for new driving and CO buildup suspected for new driving and

parking procedures on flat top conveyorparking procedures on flat top conveyor– CO levels data-logged in various areas ventilation CO levels data-logged in various areas ventilation

on and offon and off– CO levels data-logged while different procedures CO levels data-logged while different procedures

were used for idling cars while parkedwere used for idling cars while parked

• Determined that new procedures did increase Determined that new procedures did increase CO to hazardous levels in one area.CO to hazardous levels in one area.

• Immediate ventilation system changes Immediate ventilation system changes reduced maximum CO levels to non hazardous reduced maximum CO levels to non hazardous levels levels

Care Line CO Levels (02/28/97)

0

1

2

3

4

5

6

7

8

9

10

10:3

010

:34

10:3

810

:42

10:4

610

:50

10:5

410

:58

11:0

211

:06

11:1

011

:14

11:1

811

:22

11:2

611

:30

11:3

411

:38

11:4

211

:46

11:5

011

:54

11:5

812

:02

12:0

612

:10

12:1

412

:18

12:2

212

:26

12:3

0

pp

m C

O

Area sample between north and centre lines, south of Col. A1 126 Area sample between north and centre lines south od Col. A1 128

Area sample between centre and south lines north of Col. A 126 Area sample between centre and south lines north of Col. A 128

COAST CLUTCH BLOWOFFCOAST CLUTCH BLOWOFFINSTRUMENT-DATARAM AEROSOL MONITORINSTRUMENT-DATARAM AEROSOL MONITOR

• Using compressed air to blow off and clean Using compressed air to blow off and clean

Transmission parts. Does ventilated box Transmission parts. Does ventilated box and lower air pressure reduce exposures.and lower air pressure reduce exposures.– Total particulates data-logged while Total particulates data-logged while

blowing off parts in general work areablowing off parts in general work area– TP’s data-logged with part held in TP’s data-logged with part held in

ventilated boxventilated box• Determined box increased exposures since Determined box increased exposures since

exhaust in box too low, and blow backexhaust in box too low, and blow back• Lower air pressure decreased exposuresLower air pressure decreased exposures

Parts Blow-off Investigation

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9T

P (

mg

/m3)

BLACK PRIMEBLACK PRIMEINSTRUMENT-CENTURY SYSTEMS OVAINSTRUMENT-CENTURY SYSTEMS OVA• Black prime with MEK applied to window openings Black prime with MEK applied to window openings

on ventilated ramp, employees complain of on ventilated ramp, employees complain of irritation and odoursirritation and odours

• How did casablanca fan speed and application How did casablanca fan speed and application method affect exposuresmethod affect exposures– MEK levels taken in BZ and general area with MEK levels taken in BZ and general area with

fans on high 3X higher than fans on lowfans on high 3X higher than fans on low– MEK peak levels taken In BZ while leaning over MEK peak levels taken In BZ while leaning over

applied prime 4X higher than when furthest part applied prime 4X higher than when furthest part of window was primed firstof window was primed first

• Set fans to low speed, disabled rheostatsSet fans to low speed, disabled rheostats• Rec’d not to lean over applied prime Rec’d not to lean over applied prime

PAINT SPRAYINGPAINT SPRAYINGINSTRUMENT- CENTURY SYSTEMS OVAINSTRUMENT- CENTURY SYSTEMS OVA• Employees paint spraying rear of vehicleEmployees paint spraying rear of vehicle• Long term test showed paint solvent Long term test showed paint solvent

exposures <5 ppm, but employees continued exposures <5 ppm, but employees continued to complain of irritation and odoursto complain of irritation and odours– sampled BZ while spraying across from each sampled BZ while spraying across from each

other, found peaks of 200 ppm TOHC from other, found peaks of 200 ppm TOHC from oversprayoverspray

– sampled BZ while staggering their spraying, sampled BZ while staggering their spraying, found peaks below 10 ppmfound peaks below 10 ppm

• Recommended that paint sprayers in all Recommended that paint sprayers in all booths stagger their paint sprayingbooths stagger their paint spraying

METAL WORKING FLUIDSMETAL WORKING FLUIDSINSTRUMENT- MINIRAM AEROSOL MONITOR INSTRUMENT- MINIRAM AEROSOL MONITOR • Employees working on machining line Employees working on machining line

complaining of irritation, all equipment complaining of irritation, all equipment ventilatedventilated– Miniram used to survey BZ and general work Miniram used to survey BZ and general work

areaarea– Levels in area rose slowly as machining Levels in area rose slowly as machining

progressedprogressed– followed plume of mist back to one faulty filterfollowed plume of mist back to one faulty filter– after filter repaired, levels remained lowafter filter repaired, levels remained low

• Recommended preventative maintenance on Recommended preventative maintenance on filters of ventilation equipmentfilters of ventilation equipment

METAL WORKING FLUIDSMETAL WORKING FLUIDSINSTRUMENT(S)- DATARAM AEROSOL MONITOR & INSTRUMENT(S)- DATARAM AEROSOL MONITOR &

TSI DUSTRACTSI DUSTRAC

• Total Particulate Levels Required to Determine Total Particulate Levels Required to Determine Need For Engineering ControlsNeed For Engineering Controls– Total Particulate Mapping of Component Total Particulate Mapping of Component

Manufacturing Plants on a 6mX 6m Grid.Manufacturing Plants on a 6mX 6m Grid.– Results plotted on an Excel Spreadsheet. Chart of Results plotted on an Excel Spreadsheet. Chart of

Exposure Levels (Contour) Printed on Overhead.Exposure Levels (Contour) Printed on Overhead.– Contour Chart Overlaid on Plant Layout.Contour Chart Overlaid on Plant Layout.– Areas of Higher Exposure Targeted for Areas of Higher Exposure Targeted for

ImprovementImprovement– Engineering Controls installedEngineering Controls installed– Plant is Remapped to Determine ImprovementPlant is Remapped to Determine Improvement

ConclusionsConclusions• Is sampling necessary, can the problem be solved Is sampling necessary, can the problem be solved

another way?another way?

• Ensure your sampling strategy is right.Ensure your sampling strategy is right.

• Real time air monitoring benefits include:Real time air monitoring benefits include:– ability to determine patterns of exposureability to determine patterns of exposure– ability to quickly evaluate engineering or ability to quickly evaluate engineering or

process control changesprocess control changes– reasonably determine potential of exposure to reasonably determine potential of exposure to

cause adverse health effects cause adverse health effects – dollar savings from reduction of lab analysis and dollar savings from reduction of lab analysis and

hygienist’s time being used more effectivelyhygienist’s time being used more effectively