INHALABLE PARTICULATE

MATTER

SAMPLING OPTIONS FROM SKC INC

A GLOBAL DISCONNECTGlobal differencesin definitions of workplacecontaminants and standard sampling methods for thosecontaminantscreate a variety of problems.

GLOBAL DIFFERENCES IN DEFINTIONS

Complicate international comparisons and sharing of data

Make our profession seem illogical to lay people including legislators

Contribute to differences in worker protection in different countries

Complicate the choice of sampling equipment

GLOBAL DIFFERENCES IN SAMPLERS

Result in considerable differences in exposure measurements when sampling the same contaminant under identical environmental conditions.

A COMMON SENSE APPROACH

Since we are interested in health effects, researchers sought to design a personal sampler that would be based “on a biologically relevant definition of total dust, that is, one which represents the total of what the worker takes in through the nose and/or mouth during the act of breathing”. (Ann. Occup. Hyg. Vol. 30, 1986.)

HISTORICAL EVENTS

A Move Toward

StandardizationACGIHISOCEN

HISTORICAL EVENTS In 1982, ACGIH appointed an ad hoc

committee on Air Sampling Procedures (ASP) with the task of preparing recommendations for size-selective sampling that would lead to an approach for establishing particle size-selective TLVs for particulates.

HISTORICAL EVENTS In 1983, ISO published Technical

Report 7708 giving definitions of particle size fractions corresponding to three regions of the respiratory tract. The fraction which would be measured would depend on the site of action of the particulate material under study.

HISTORICAL EVENTS In 1985, ACGIH published a report with

a similar proposal to that published by ISO.

In 1987, an ISO Working Group was established to revise TR7708 as an international standard and a CEN Working Group was established to produce a European standard.

HISTORICAL EVENTS In 1993, revisions to Appendix D of the

ACGIH TLV booklet, “Particle Size-Selective Sampling Criteria for Airborne Particulate Matter” were adopted by ACGIH.

Three particulate mass fractions were defined: inhalable, thoracic and respirable.

HISTORICAL EVENTS U.S. NIOSH nor OSHA have not officially

endorsed the three new international particulate definitions in total.

The only published method by U.S. government agencies using inhalable samplers is NIOSH 5700 for formaldehyde on dust specifying an IOM sampler or equivalent.

HISTORICAL EVENTSThe Health and Safety Executive

describes the use of inhalable and respirable samplers that meet the new definitions in MDHS 14/3, “General methods for sampling and gravimetric analysis of respirable and inhalable dust”.

HISTORICAL EVENTSAustralia has embraced the new

definitions of inhalable and respirable particulate mass in the new drafts of the Australian Standards for sampling and gravimetric determination of inhalable dust (AS 3640) and respirable dust (AS2985).

MOVING FORWARDDefinitions Performance

SpecificationsSamplersExposure Limits

INHALABLE PARTICULATE MASS

Defined as those materials that are hazardous when deposited anywhere in the respiratory tract

Includes particulate matter that enter the head airways region including the nose and mouth

Also includes materials that can produce systemic toxicity from deposition anywhere in the respiratory system.

INHALABLE SAMPLERS Meet the inhalability criterion when a personal

sampler mounted on the body gives the same measured dust concentration and aerodynamic size distribution as that inhaled by its wearer, regardless of dust source location and wind conditions.

Defined as having a 50% cut-point of 100 microns.

TRADITIONAL FILTER CASSETTES

Do not effectively sample inhalable particulate matter

They significantly underestimate the concentration of larger dust particles from 30-100 m.

The inlets do not effectively capture the larger particles, particles adhere to the cassette walls and sample loss can occur when removing the filters.

INHALABLE SAMPLERS

A personal sampler for inhalable

particulate was first developed by Mark

and Vincent in 1986 at the Institute of

Occupational Medicine and licensed for

manufacture by SKC.

IOM SAMPLER(SKC Cat. No. 225-70A)

Exploded View

USING THE IOM SAMPLERSAMPLE LOGISTICS

Load a 25-mm filter into the cassette using forceps and wearing gloves.

Equilibrate the filter/cassette assembly overnight under controlled humidity conditions then weigh them as a unit.

Allow the assembly to stabilize a few minutes before taking a reading.

USING THE IOM SAMPLERSAMPLE LOGISTICS

Place the IOM cassette/filter assembly into the sampler body, screw on the cover cap, and connect to the pump.

Calibrate the flow rate to 2 L/min using the IOM Calibration Adapter (Cat. No. 225-73) or by placing in a calibration chamber.

Following sample collection, weigh the cassette/filter assembly again following the procedures described above.

USING THE IOM SAMPLERSAMPLE LOGISTICS

Transport clips are available to transport the filter/cassette assemblies to the sampling site or the laboratory (Cat. No. 225-72A).

ADVANTAGES OF THE IOMSince the filter and cassette are

weighed together, all particles which enter through the sampling inlet are part of the analysis.

Any particulate dislodged from the filter due to accidental knocking, will be retained inside the cassette and weighed.

ADVANTAGES OF THE IOMThe collection efficiency gives an

acceptable match to the inhalability definition when worn on the lapel as a personal sampler.

The performance is relatively independent of wind speed for particles with aerodynamic diameter up to and including 75 m.

WEIGHING ACCURACY OF IOM SAMPLES

CONCERNS March/April 1999

AIHA Journal article discusses problems of water absorption by plastic IOM cassette and resulting instability of the tare weight

RESPONSE SKC has changed the

plastic material to address water. adsorption.

Do not desiccate Equilibrate under

controlled humidity conditions.

Consider stainless steel cassettes.

Studied the use of porous polyurethane foams as size-selectors

Placed in the inlet of the IOM sampler Allow for the collection of inhalable and

respirable sub fraction using existing IOM samplers

Followed by gravimetric analysis Used for a variety of particulates

including bioaerosols

NEW IOM RESEARCHBY U.K. HEALTH AND SAFETY

LABORATORY

IOM SAMPLERWITH MULTIDUST FOAM DISCS

InhalableRespirable

UNDER STUDY Thoracic PM10 Combination discs

New Cassette with Elongated Inlet Required

PUBLICATIONS ON IOMBY HSE LAB

HSE Lab Publication on Foam Discs, Project Leader: L C Kenny

Journal of Aerosol Science, Vol. 30, No. 5, pp. 627-638, 1999 on sampling efficiency with low air movement

AIHA Journal, Vol. 59, pp. 831-841, 1998 on sampling with foams for bioaerosols

Methods for the Determination of Hazardous Substances 14, Health and Safety Executive, January 1997

NEW INHALABLE RESEARCHBY UNIV OF CINCINNATI

Button Sampler -Alternative to the IOM sampler for inhalable dust

Inlet is formed from a spherical

shell with numerous, evenly

spaced holes Holes act as orifices and

provide multidirectional

sampling capabilities

Cat. No. 225-360

USING THE BUTTON SAMPLERSAMPLE LOGISTICS

Unscrew the sampler inlet and remove the PTFE O-ring.

Place a 25-mm filter on the stainless steel support screen, replace the 0-ring and the sampler inlet.

A filter pore size of 1.0 m or higher is recommended due to the backpressure limitations of personal samplers.

USING THE BUTTON SAMPLERSAMPLE LOGISTICS

Calibrate the Button Sampler to a flowrate of 4 L/min using the calibration adapter (Cat. No. 225-361) or by placing in a calibration chamber.

After sampling, remove the filter for analysis. SKC offers a conductive plastic filter transport case for shipment to the lab. (Cat. No. 225-67)

ADVANTAGES OF BUTTON SAMPLER

Closed-face inlet keeps out large particles 25-mm filter directly behind inlet avoids

transmission losses in sampler Uniform distribution of holes minimizes

sensitivity to wind velocity and direction Flow rate of 4 L/min for personal

sampling increases sensitivity Can be used for personal or area sampling

PUBLICATIONS ON BUTTON SAMPLER

BY UNIV OF CINCINNATI AIHA Journal, Vol.

61, 398-404, 2000 on performance characteristics

Aerosol Science and Technology, Vol. 28, 247-258, 1998 on effects of wind velocity and direction

AIHA Journal, Vol. 58,713-719, 1997 on field testing of sampler

Atmospheric Environment, Vol. 29, No. 10, pp. 1105-1112, 1995 on design of prototype

CONCLUSIONS REPORTED For the Button Personal Sampler

Effects of wind direction: No significant effects

Effects of wind velocity: Lower than for IOM, GSP and 37-mm cassette

Accuracy (direction-averaged): Better an 37-mm cassette, comparable to GSP, lower than IOM

Precision (direction-specific): Equal or better than IOM, GSP, or 37-mm cassette

ABRASIVE BLASTING

A NIOSH Health Hazard Evaluation indicated that current methods do not provide reliable measurements of worker exposure to lead and other contaminants during abrasive blasting in small confined spaces.

ABRASIVE BLASTINGCurrent sampling

methods using 37-mm cassettes often grossly overestimate exposure to very large, noninhalable particulate.

In NIOSH HHEs, nearly all of the lead in the samples was due to grit that entered the cassettes due to rebound of grit in confined spaces.

JOURNAL ARTICLE

APPLIED OCCUPATIONAL AND

ENVIRONMENTAL HYGIENE, Vol. 15, p. 776-772, 2000 on use of Button

Sampler with screen for evaluating metal

exposures among abrasive blasting

workers at four US Air Force

Facilities

OTHER INHALABLE SAMPLERS

7-HOLE SAMPLING HEAD

Traditional European method using a 25-mm filter and cassette with an end cap with 7 equispaced inlet holes with flows of 2.0 L/min.

INHALABLE TLVs2010 ADOPTED VALUES

Acrylamide Alachlor Aldrin Asphalt Fume Azinphos-methyl Benomyl Beryllium Borate cpds,

Inorganic Butylated

hydroxytoluene Calcium sulfate Caprolactam

Captan Carbaryl Carbofuran Chlorpyrifos Citral Coumaphos Cresol (all isomers) Demeton (and

Demeton-S-methyl) Diazinon Dibutyl Phosphate 2,2-Dichloropropionic

acid

INHALABLE TLVs2010 ADOPTED VALUES

Dichlorvos (DDVP) Dicrotophos Dieldrin Diesel Fuel Diethanolamine Dioxathion Diquat Disulfoton Endosulfan EPN Ethion 2-Ethylhexanoic acid Fenamiphos

Fensulfothion Fenthion Ferbam Flour Dust Fonofos Glyoxal Hexahydrophthalic

anhydride Iodine and Iodides Isobutyl nitrite Magnesium oxide Malathion Methyl demeton

INHALABLE TLVs2010 ADOPTED VALUES

Methyl parathion Mevinphos Mineral oil (excluding metal

working fluids) Molybdenum (Metal and

insoluble cpds.) Monochloroacetic acid Monocrotophos Naled Natural rubber latex as total

proteins Nickel, Elemental, Soluble

and Insoluble Cpds.

Nickel Subsulfide 5-Nitro-o-toluidine p,p-Oxybis (benzene

sulfonyl hydrazide) Parathion Particulates Not

Otherwise Specified (now a guideline; not a TLV)

Phorate m-Phthalodinitrile Ronnel

INHALABLE TLVs2010 ADOPTED VALUES

Silicon carbide, nonfibrous

Sulfotepp (TEDP) Sulprofos Synthetic Vitreous

Fibers (Continuous filament)

Temephos Terbufos 1,1,2,2-

Tetrabromomethane

Tetraethyl pyrophosphate (TEPP)

Thallium (and compounds, as TI)

Thiram Trichlorphon Trimellitic anhydride Vanadium Pentoxide Wood dusts Xylidine (mixed

isomers)

INHALABLE TLVs2010 INTENDED CHANGES

Carbon black Maleic anhydride Manganese (elemental

and inorganic cpds., as Mn)

Piperazine 4,4-Thiobis (6-tert-butyl-

m-cresol) Toluene 2,4- or 2,6-

diisocyanate (or as a mixture)

DATA CONVERSION??TOTAL TO INHALABLE

Aerosol Classification and Conversion Factor-Dust 2.5-Mist 2.0-Foundries 1.5-Welding 1.0-Smokes/fumes 1.0

Published by Werner et. al. in the Analyst, 121:1207

THE FUTURE OF SIZE-SELECTIVE SAMPLING

More inhalable TLVsNew thoracic TLVsDevelopment of thoracic samplersEnhanced use of foams as pre-

selectors