Transcript INHALABLE SAMPLING

INHALABLE SAMPLING
Winnipeg – November 2003
Doug Dowis
DEBORAH F. DIETRICH, CIH
SKC INC.
www.skcinc.com
Jon O’Brien – Integra Environmental
Overview
 Introduction
to SKC
 Issues with Sampling Inhalable
Particulates
 Sampling Methods
SKC

The Leader In Air Sampling
Technology
 With Over 40 Years Experience
SKC: International Distribution

Distribution Partners in Over 40
Countries
 SKC Ltd. in England
 Integra Environmental:
A Very Long & Good Relationship
Offices
in Ontario and
Richmond
SKC: Innovations



From the First Sorbent
Tube for Personal
Sampling
To New Sampling
Methods
And Products to Make
Your Job Easier
STATEMENT OF THE
PROBLEM
Global differences
in definitions of
workplace
contaminants and
standard sampling
methods for those
contaminants
create a variety of
problems.
Global Disconnect
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
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
Standardization
 ACGIH
 ISO
 CEN
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 sizeselective 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 SizeSelective Sampling Criteria for Airborne
Particulate Matter” were adopted by
ACGIH.
 Three particulate mass factions were
defined: inhalable, thoracic and
respirable.
HISTORICAL EVENTS
 US
NIOSH nor OSHA have not officially
endorsed the three new international
particulate definitions in total.
 The only published method by US
government agencies using inhalable
samplers is NIOSH 5700 for
formaldehyde on dust specifying an
IOM sampler or equivalent.
HISTORICAL EVENTS
 The
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 EVENTS
 Australia
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 FORWARD
 Definitions
 Performance
Specifications
 Samplers
 Exposure 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 30100 um.
 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 SAMPLER
SAMPLE 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 SAMPLER
SAMPLE LOGISTICS

Place the IOM cassette/filter assembly into
the sampler body, screw on the cover cap,
and connect to the pump.
 Calibrate the flowrate 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 SAMPLER
SAMPLE LOGISTICS
 Transport
clips are available to transport
the filter/cassette assemblies to the
sampling site or the laboratory (Cat. No.
225-72A).
 Conductive plastic caps are available to
cover the inlet of the IOM for transport
of an IOM loaded with the filter/cassette
assembly (Cat. No. 225-78).
ADVANTAGES OF THE IOM
 Since
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 IOM
 The
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 um.
WEIGHING ACCURACY OF
IOM SAMPLES
CONCERNS
RESPONSE


March/April 1999
AIHA Journal
article discusses
problems of water
absorption by
plastic IOM
cassette and
resulting
instability of the
tare weight
SKC has changed
the plastic material
to address water.
adsorption.
 Do not desiccate
 Equilibrate under
controlled humidity
conditions.
 Consider stainless
steel cassettes.
NEW IOM RESEARCH
BY UK HEALTH AND SAFETY
LABORATORY

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
IOM SAMPLER
WITH MULTIDUST FOAM DISCS
 Inhalable
 Respirable
UNDER STUDY
 Thoracic
 PM10
 Combination discs
New Cassette Required
With Elongated Inlet
PUBLICATIONS ON IOM
BY 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 RESEARCH
BY 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 SAMPLER
SAMPLE LOGISTICS
 Unscrew
the sampler inlet and remove
the Teflon® 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 um or higher is
recommended due to the backpressure
limitations of personal samplers.
USING THE BUTTON SAMPLER
SAMPLE 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 (directionaveraged): Better
an 37-mm cassette,
comparable to GSP,
lower than IOM
 Precision (directionspecific): 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 BLASTING
 Current
sampling
methods using
37-mm cassettes
often grossly
overestimate
exposure to very
large,
noninhalable
particulate.
 In
NIOSH HHE’s,
nearly all of the
lead in the
samples was due
to grit that
entered the
cassettes due to
rebound of grit in
confined spaces.
NIOSH SHIPYARD ABRASIVE
BLASTING PROJECT
 NIOSH
is comparing sampling methods
for this application.
 Study protocol includes a comparison of
37-mm cassette vs. Button Sampler vs.
Shielded Button Sampler.
 NIOSH representatives from New
England and Atlanta Field Office’s are
involved.
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.
OTHER INHALABLE
SAMPLERS

CIS (GSP)
SAMPLER
The conical inhalable
sampler aspirates
aeorsols through the
inlet at a flow rate of
3.5 L/min onto a
37-mm filter.

RESPICON
Aerosol is aspirated at
a flow rate of 3.1 L/min
and separated into
three fractions by two
virtual impactors.
INHALABLE TLVs
2002 ADOPTED VALUES

Asphalt Fume
 Azinphos-methyl
 Butylated
hydroxytoluene
 Captan
 Demeton (and
Demeton- S-methyl)
 2,2Dichloropropionic
acid

Dichlorvos
 Dicrotophos
 Dioxathion
 Diquat
 Disulfoton
 2-Ethylhexanoic acid
 Flour Dust
 Glyoxal
INHALABLE TLVs
2002 ADOPTED VALUES






Molybdenum (Metal and
insoluble cpds.)
Monocrotophos
Naled
Nickel, Elemental,
Soluble and Insoluble
Cpds.
Nickel Subsulfide
Particulates (Insoluble)
Not Otherwise
Classified

p,poxybis(benzenesulfonyl
hydrazide)
 Silica, Amorphous
(Diatomaeous earth)
 Synthetic Vitreous
Fibers (Continuous
filament)
 Terbufos
 Xylidine (mixed
isomers)
INHALABLE TLVs
2002 INTENDED CHANGES

Beryllium and
compounds
 Caprolactam
 Chlorpyrifos
 Diazinon
 EPN
 Ethion
 Isobutyl nitrite

Magnesium oxide
 Malathion
 Mevinphos
 Oil Mist, Mineral
 Parathion
 Silicon carbide,
nonfibrous
 Sulfuric acid
 Trichlorphon
 Wood Dust
INHALABLE TLVs
INTENDED CHANGES

Mevinphos
 Monocrotophos
 Naled
 Oil Mist, Mineral
 Parathion
 Silicon carbide,
nonfibrous

Sulfuric acid
 Terbufos
 Trichlorphon
 Wood Dust
 Xylidine (mixed
isomers)
TOTAL vs INHALABLE LEVELS
E IOM / E 37 mm
IOM will measure higher exposures
than the 37-mm cassette:
11.5% (10-56 um sized particles)
66% (57+ um sized particles)
Presentation at 2000 AIHCE in Orlando.
TOTAL vs INHALABLE LEVELS
E IOM / E 37 mm
 Lead
 Cadmium
 Oil
Mist
 Carbon Black
1.39-2.14
1.29-2.12
2.36-3.56
2.7*
*Paper presented at 1999 AIHCE
THE FUTURE OF SIZESELECTIVE SAMPLING
 More
inhalable TLVs
 New thoracic TLVs
 Development of thoracic samplers
 Enhanced use of foams as preselectors