ANOTHER EDITION OF….

DUSTY DEBBIEblasts particulate

matters.

THE EMERGENCE OF NEW DUST SAMPLERS FOR

NEW ISSUES

SPECIAL FOCUS: 2013 OSHA PROPOSED RULEMAKING ON SILICA

WHY DO WE NEED NEW DUST SAMPLERS?

New concerns with traditional samplers New criteria for size-selective sampling New regulations and guidelines New priorities and demands from users

NEW CONCERNSWITH TRADITIONAL SAMPLERS

US NIOSH and OSHA scientists have been addressing sample losses with traditional 37-mm filter cassettes.

Of particular concern, are sample losses that occur from particles that adhere to the interior cassette walls and are not analyzed.

U.S. OSHA STATEMENTIN HEXAVALENT CHROMIUM METHOD

“Tests showed that Cr (VI) equivalent to 0 to 123% of the amounts found on the PVC filter were present on the interior walls of cassettes used for compliance samples. It is now routine procedure to wipe interior walls of sampling cassettes for all metal samples analyzed.”

Source: United States. Occupational Safety and Health Administration. Hexavalent Chromium. 30 Apr 2009 <http://www.osha.gov/dts/sltc/methods/inorganic/id215_v2/id215_v2.html>

NIOSH STATEMENTIN AIHA JOURNAL ARTICLE

Dust deposits on the walls of filter cassettes were 19% of the total sample for lead and 25% of the total sample for copper.

Filter cassettes should be rinsed and wiped prior to analysis.

Source: Ashley, Kevin, Harper, Martin and Demange, Martine.“Concerning Sampler Wall Deposits in the Chemical Analysis of Airborne Metals.” Journal of Occupational and Environmental Hygiene 4:9 Sept 2007: D81 - D86 <http://dx.doi.org/10.1080/15459620701493149>

ACCU-CAP EMERGESTO ADDRESS CONCERNS

Filter insert that is placed into a 2-piece cassette with support pad.

Consists of a clear plastic dome heat-sealed to a filter.

Dust is collected onto the filter or within the dome for gravimetric analysis.

PVC ACCU-CAP FOR GRAVIMETRIC ANALYSIS

A NEW SOLU-CAP EMERGESBASED ON NIOSH RESEARCH

Designed for chemical analysis of metals Mixed cellulose ester filter heat sealed to acid

digestible cellulose acetate dome Pre-loaded into 2-piece cassettes with

support pads Eliminates the need to wipe the inside of the

cassette to obtain reliable exposure measurements Source: Ashley, Kevin, Harper, Martin. “Acid-Soluble

Internal Capsules for Closed-Face Cassette Elemental Sampling and Analysis of Workplace Air.” Journal of Occupational and Environmental Hygiene 10:6, 297-306, February 25, 2013.

NEW CRITERIAFOR SIZE-SELECTIVE SAMPLING

In 1993, ACGIH joined with ISO and CEN in defining particulates in terms of inhalable, thoracic, and respirable particulate mass fractions.

See page 80 of the 2013 TLV handbook.

NOTE FOR NEWCOMERS:CURRENT PARTICULATE FRACTIONS

Inhalable-particles that are hazardous when deposited anywhere in the respiratory system (including those that enter nose/mouth)

Thoracic-particles hazardous when deposited

anywhere within the lung airways and gas-

exchange region Respirable-particles hazardous when deposited

in the alveolar gas-exchange region.

PERFORMANCE SPECS FOR DUST SAMPLERS

Aerodynamic Particle Diameter, da, m

1 10 100

Sam

plin

g E

ffic

ien

cy, E

, %

0

25

50

75

100

Inhalable

ThoracicRespirable

INHALABLE PARTICULATE:A CLOSER LOOK

Review of pertinent scientific issues presented at an AIHCE sessionThe impact on dust samplers

HISTORICAL PERSPECTIVE: TERMS AND SPECIFICATIONS

Except in cases where diseases are caused by fine respirable dust, it has been common practice to sample so-called total dust.

This is in general recognition that all inhaled particles could present either a specific or non-specific risk to health. (Mark and Vincent, Ann. Occup. Hyg.,1986.)

PROBLEMS WITH TOTAL DUST:SPECIFICATIONS

Total dust has never been defined by a specific size range and a 50% cut-point (D50) was never established for total dust samplers.

Given the vague definition of total dust, a number of personal samplers with various performance characteristics have been used for sampling total dust around the world.

TOTAL DUST SAMPLERSUSED GLOBALLY

Single-hole head

7-hole head

37- or 25-mm filter cassettes

SURPRISING STATISTICS:SAMPLER PERFORMANCE

There is very limited data available on how well these samplers actually measure the true dust exposure.

Studies show considerable differences in results from these various samplers when sampling the very same dust under the identical environmental conditions. (Mark and Vincent, 1986)

≠≠

SURPRISING STATISTICS:LIMITATIONS OF 37-MM CASSETTES

37-mm Filter Cassettes: Were never designed to represent a

physiologically relevant exposure to the respiratory system.

Aspiration efficiency is not very similar to the nose and mouth.

Are not 100% efficient in collecting all sizes of dust particles.

Have a upper size limit (approx. 30 um) where efficiency falls to zero.

(T. Renee Anthony, AIHCE 2011)

SURPRISING STATISTICS:ERRORS WITH 37-MM CASSETTES

Sampling errors with 37-mm cassettes

can occur from: Ambient wind velocity effects Orientation effects Dust deposition on walls of cassette

INHALABLE SAMPLERS EMERGE

Since occ hygienists are concerned with the health-related dose, new dust samplers have emerged that measure dust concentrations with the same efficiency as we inhale them.

THE IDEAL DUST SAMPLER

An inhalable sampler is considered ideal “when a personal sampler mounted on the body gives the same measured dust concentration and aerodynamic size distribution as that inspired by its wearer, regardless of dust source location and wind conditions”. (Mark and Vincent, 1986)

Inhalable samplers have a 50% cut-point of 100 microns.

INHALABLE SAMPLERS:FOR THE NEW CRITERIA

The first personal sampler specifically designed for inhalable particulate mass was developed by Mark and Vincent in 1986 at the Institute of Occupational Medicine in Scotland and was licensed to SKC Ltd. in the U.K.

SKC 225-70A

ADVANTAGES OF THE IOM SAMPLER: TECHNICAL

Developed specifically to match the inhalable definition.

Precise fit to the inhalable curve at 2 L/min Conductive plastic cassette for gravimetric and

stainless steel cassette for chemical analysis. Internal wall deposits are included in the sample

analysis. Can be combined with a foam insert to collect

the respirable fraction simultaneously.

ADVANTAGES OF THE IOM SAMPLER: CONFORMANCE

The IOM is specified by name in many standards/methods including UK HSE Method 14/3; Australian Standard 3640, and NIOSH Method 5700.

In response to an SKC inquiry, U.S. OSHA issued a statement indicating the IOM could be used as an equivalent sampler for particulates not otherwise classified. Copies available upon request.

OTHER INHALABLE SAMPLERS:BUTTON SAMPLER

Designed for use at

4 L/min to enhance sensitivity

Inlet has a stainless steel inlet screen to keep out large, non-inhalable projectiles from impacting or splashing onto the filter.

Suitable for area or personal sampling. SKC 225-360

SWEDISH MINI-SAMPLER FOR INHALABLE MANGANESE

Enable positioning of the sampler inlet within close proximity of the welder’s nose and mouth even when wearing a face shield.

Used with the SKC Face Level Sampling Head Set

Mini-Sampler SKC 225-6201

Headset SKC 225-6200

Developed in a research project partly funded by the Swedish Work Environment Authority and carried out at Stockholm University, Sweden.

MINI-SAMPLER COMPONENTS

13-mm Swinnex filter holder modified into an open-face filter holder.

Incorporates a specially designed aluminum entry nozzle which protrudes out the front of the holder as the sampler inlet.

PTFE-coated O-ring and the retaining ringholds the 13-mm filter in place in the sampler body.

Figure 1

MINI-SAMPLER:ADVANTAGES/APPLICATIONS

Advantages: The headset mounting

arrangement improves personal sampling as it

maintains the sampler close to nose/mouth.

Applications: Only for inhalable sampling where

90% of the mass size distribution is below 20

um (including manganese).

DATA COMPARISON??TOTAL VS INHALABLE

Inhalable particulate mass is typically greater than so-called total particulate mass. How much greater will depend upon the SIZE of the

particles. With larger particles, inhalable particulate mass will

be much greater than total particulate mass. With smaller particles, inhalable and total particulate

mass will be comparable.

A CONVERSION FACTOR??TOTAL VS INHALABLE

So what do you do? Collect side-by-side

37-mm cassette and inhalable samples and determine process-specific conversion factors for YOUR unique application.

The AIHCE session made the point that it is really not enough to use a simple conversion factor from total to inhalable as there are too many variables.

2013 TLVs®

ISSUED AS INHALABLE

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

Inorganic Butylated

hydroxytoluene

Calcium sulfate Caprolactam Captan Carbaryl Carbofuran Carbon Black Chlorpyrifos Citral Coumaphos Cresol, all isomers

2013 TLVs®

ISSUED AS INHALABLE Demeton (and Demeton-

S-methyl) Diazinon Dibutyl phosphate 2,2-Dichloropropionic

acid Dichlorvos (DDVP) Dicrotophos Dieldrin Diesel Fuel Diethanolmine Dioxathion

Diquat Disulfoton Endosulfan EPN Ethion 2-Ethylhexanoic acid Fenamiphos Fensulfothion Fenthion Ferbam Flour Dust Fonofos

2013 TLVs®

ISSUED AS INHALABLE Glyoxal Hexahydrophthalic

anhydride Iodine and Iodides Isobutyl nitrite Magnesium oxide Malathion Maleic anhydride Methyl demeton 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.

2013 TLVs®

ISSUED AS INHALABLE 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- and o-Phthalodinitrile Piperazine and salts

Ronnel Silicon carbide,

nonfibrous Sulfotepp (TEDP) Sulprofos Synthetic Vitreous

Fibers (Continuous filament)

Temephos Terbufos 1,1,2,2-

Tetrabromomethane

2013 TLVs®

ISSUED AS INHALABLE

Tetrethyl pyrophosphate (TEPP)

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

m-cresol) Thiram Trichlorphon

Trimellitic anhydride Vanadium pentoxide Wood Dusts Xylidine (mixed

isomers)

2013 INTENDED CHANGES TO TLVs®

ISSUED AS INHALABLE

Clopidol 2,4-D Diethylene glycol

monobutyl ether Manganese, elemental

and inorganic cpds. O-Phthalodinitrile Piperazine and salts 2,4- or 2,6- Toluene

diisocyanate Tributyl phosphate

For TLVs with IFV notation (Inhalable fraction and vapor)

There is no single sampler that can be used.

Requires (2) separate samples: one for each contaminant phase.

THORACIC PARTICULATE:A CLOSER LOOK

Definitions of size fractionSpecifications for samplersSampler optionsApplications

THORACIC PARTICULATEDEFINED

Thoracic particulate is defined as material hazardous when deposited within the lung airways and down into the gas exchange region.

Thoracic samplers have a 50% cut-point of 10 um.

THORACIC SAMPLERSEMERGE

The first thoracic sampler was developed by BGI Inc.

The BGI GK 2.69 cyclone is used with standard 37-mm cassettes at a flowrate of 1.6 L/min.

This sampler is listed in the NIOSH method for metalworking fluids.

THORACIC SAMPLERS:ANOTHER OPTION

SKC offers an impaction based sampler for thoracic particulate called the Parallel Particle Impactor or PPI.

The thoracic PPI is used with any suitable

37-mm filter at a flowrate of 2.0 L/min.

SKC 225-386

U.S. Patent No. 7,073,402

Single-use, disposable model 225-386

PPI OPERATING PRINCIPLE

The disposable PPI looks like a traditional 37-mm filter cassette.

But the inlet section has 4 internal, pre-oiled impactor plates that scrub out larger particles.

The dust size-fraction of interest is collected onto the filter in the outlet section for analysis.

PERFORMANCE OF SKC AND BGI THORACIC SAMPLERS

Aerodynamic Particle Diameter, da, m

Pen

etra

tio

n, P

, %

0

25

50

75

100

GK2.69 (BGI)

Thoracic Convention

0.5 1 5 10 50

Thoracic PPI, QS=2.0 Lpm

THORACIC SAMPLERSCURRENT APPLICATIONS

Thoracic TLVs Sulfuric Acid Cotton Dust

NIOSH Methods NIOSH Method 5524,

for metalworking fluids specifies a

2-um PTFE filter in a

37-mm filter cassette with an optional thoracic particulate sampler.

RESPIRABLE DUST: THE OSHA SILICA NPRM

U.S. OSHA published their

Notice of Proposed Rulemaking (NPRM)

for Occupational Exposure to Respirable

Crystalline Silica in September 2013 .

See this 757-page document at

https://www.osha.gov/silica/nprm.pdf

NOTABLE ISSUE IN THE NPRM:PELs-CURRENT

GENERAL INDUSTRY

A formula based on the % silica in the air sample. Example:

_____10____ % Quartz + 2

PEL is equivalent to 100 ug/m3 when the material is pure quartz . PEL approaches 5 mg/m3, (the PEL for Particulates Not Otherwise Classified) with a low percentage of quartz in the sample.

.

CONSTRUCTION AND

SHIPYARDS

A formula based on obsolete

method of collecting dust into

impingers with analysis by

particle counting.

PEL is approximately

equivalent to 250 ug/m3.

NOTABLE CHANGE IN THE NPRM:PEL-PROPOSED

50 ug/m3 as an 8-hr TWA for all forms of

silica including quartz, cristobalite, and

trydymite for all industry sectors covered by

the rule.

25 ug/m3 action level (same as current TLV)

NOTABLE ISSUE IN THE NPRM:SAMPLER SPECS-CURRENT

Current specs for respirable dust samplers were promulgated in 1971 and are listed in 29 CFR 1910.1000; Table Z-3 for mineral dusts.

Table Z-3 lists the required collection efficiencies of samplers for various particle sizes. Ex. Particles with a diameter of 3.5 um should be collected with 50% efficiency. (50% cut-point) The 25, 75, and 90% cut-points are also listed.

The Dorr-Oliver (nylon) cyclone is the only samplerused by federal OSHA inspectors to meet these specs.

NOTABLE CHANGE IN THE NPRM: SAMPLER SPECS-PROPOSED

Page 539: OSHA acknowledges that the current collection efficiency specs for samplers are obsolete.

Page 542: OSHA states that crystalline silica measurement should be determined by a sampling device designed to meet the characteristics for particle-size-selective samplers specified in ISO 7708:1995 Air Quality-Particle Size Fraction Definitions for Health-Related Sampling.

ISO 7708:1995

This is the standard that ACGIH, NIOSH, CEN, and most countries around the world have already adopted.

The collection efficiency curve for respirable dust samplers in this standard includes a 50% (median) cut-point of 4 um which is more conservative than the existing OSHA specification.

TRADITIONAL SAMPLERS: TO MEET SPECS IN ISO 7708

CYCLONES FROM SKC/FLOWRATES Aluminum Cyclone @ 2.5 L/min-Listed in

NIOSH method. Published journal article .

G(S)-3 Cyclone @ 2.75 L/min-Listed in OSHA NPRM on page 267. Published journal article.

TRADITIONAL SAMPLERS: TO MEET SPECS IN ISO 7708

OTHER CYCLONES /FLOWRATES Dorr-Oliver @ 1.7 L/minListed in NIOSH method and NPRM Higgins-Dewell @ 2.2 L/minEuropean cyclone; Listed in NIOSH method and NPRM BGI GK 2.69 @ 4.2 L/minListed in NPRM

NEW SAMPLER OPTIONS

Page 539: Adoption of this (ISO) definition by

OSHA would allow for workplace sampling to

be conducted using ANY particulate sampling

device that conforms to the ISO definition i.e.

collects dust according to the

particle collection efficiency curve specified in

the ISO standard.

RESPIRABLE PPI SAMPLERS FROM SKC

Specifically designed to precisely match the criteria for respirable samplers specified in the ISO 7708 standard.

SKC RESPIRABLE PPI:FLOWRATE OPTIONS

Single-use, disposable PPI models are available for use at either 2, 4, or 8 L/min.

This provides flexibility in pump options, sample duration, and concentration.

4 L/min: 225-387

8 L/min: 225-384

2 L/min: 225-385

PPI SAMPLER PERFORMANCECOMPARED TO CRITERIA

0

25

50

75

100

1 10

Aerodynamic Particle Diameter, da, m

Pene

trati

on, P

, %

Respirable PPI, 2.0 L/min

Respirable PPI, 4.0 L/min

Respirable PPI, 8.0 L/min

ISO/CEN Respirable Criteria

5

PPI DATA:OSHA DOCKET

SKC submitted comments to the OSHA

docket on the silica NPRM with data on

the PPI. (Electronic copies are available). The data which was published in the Journal

of Physics shows that the collection efficiency of

the PPI is a close match to the ISO standard

and the bias is more acceptable than the HD

cyclone (listed in the NPRM.)

MEETING USER DEMANDS:CONVENIENCE

Smaller size-fits under welding helmet or PPE

No assembly of impaction substrates

Pre-loaded with filters or lab loaded like a traditional cassette

No cleaning after sampling

AND FINALLY…

Another disposable size-selective sampler for diesel particulate.

Particulate emissions from diesel exhaust are VERY small particles that rapidly clump together to form particles that are still submicron in size i.e. less than 1 um in aerodynamic diameter.

DPM SAMPLER EMERGES

A single-use, disposable filter cassette for DPM was developed by U.S. NIOSH mining division and the technology was transferred to SKC for commercial production.

SKC 225-317

DPM SAMPLING TRAIN

CycloneRemoves non-respirable particles that may overload the filter

Internal Impactor Plate in CassetteRemoves respirable particles greater than 1.0 um in diameter

Heat-treated Quartz Filter assemblyCollects DPM particles less than 1.0 um in diameter for analysis of elemental carbon (EC).

THANK YOU FROM DUSTY DEBBIE

If you have questions or

need further information,

email me at

skctech@skcinc.com.