saulius trakumas, eddie salter skc inc., eighty four, united states skc ltd., blandford forum,...
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Saulius Trakumas, Eddie SalterSKC Inc., Eighty Four, United States
SKC Ltd., Blandford Forum, United Kingdom
HIGH-FLOW PERSONAL SAMPLER TO MONITOR EXPOSURE TO
RESPIRABLE CRYSTALLINE SILICA AT NEW LOWER TLV
Crystalline Silica
Crystalline silica is a basic component of soil, sand, granite,
and many other minerals.
Hazards of Crystalline Silica
Exposure to silica is a serious threat to million of workers, including workers in high risk jobs such as abrasive blasting,
foundry work, stonecutting, rock drilling, quarry work, and tunneling.
Hazards of Crystalline Silica
Occupational exposure to respirable crystalline silica is associated with the development of silicosis, lung cancer,
and other pulmonary diseases.
Hazards of Crystalline Silica
Exposures to silica may also be related to the development of
autoimmune disorders and other adverse health effects.
Recent studies have demonstrated that lifetime exposure to respirable
crystalline silica at 0.05 mg/m3 is not low enough to eliminate the risk of developing chronic lung diseases.
Permissible Exposure Limits
Permissible Exposure Limits
The American Conference of Governmental Industrial Hygienists
has lowered the 8-hour time-weighted average threshold limit
value to 0.025 mg/m3 for quartz and cristobalite.
Sampling and Analytical Methods
Current sampling and analytical methods used to evaluate occupational exposure to respirable crystalline silica
do not meet the accuracy criterion needed to quantify exposures at
concentrations below 0.05 mg/m3.
There is need for new, more sensitive, and more accurate
methods to monitor occupational exposure to crystalline silica.
Cyclone is used to remove larger particles.
Respirable fraction is collected on PVC filter.
Sampling Crystalline Silica
www.osha.gov
Operates at a flow rate 2 to 3 times higher than currently available
respirable samplers
The objective of this study was to develop and test a personal respirable sampler that:
Follows respirable convention accurately
Performance of Six Respirable Cyclones
Aluminum
Dorr-Oliver GS-1 GS-3
BGI-4CP SIMPED
Aerodynamic Particle Diameter, da, m
0 2 4 6 8 10S
am
plin
g E
ffic
ien
cy
, E,
%
0
25
50
75
100
Respirable Convention
GS-3 Cyclone, QS=2.75 L/min
Test Aerosol:
DOP Glass Spheres Coal Mine Dust
Aerodynamic Particle Diameter, da, m
0 2 4 6 8 10
Sam
plin
g E
ffic
ien
cy, E
, %
0
25
50
75
100
Respirable Convention
Aluminum Cyclone, QS=2.5 L/min
Test Aerosol:
DOP Glass Spheres Coal Mine Dust
Aerodynamic Particle Diameter, da, m
0 2 4 6 8 10
Pen
etra
tio
n, P
, %
0
25
50
75
100
Respirable Convention
Single Impactor: d50=4.0 m
Two impactors: d50=5.6, and 2.9 m
Four impactors: d50=6.6, 4.6, 3.5, and 2.2 m
Six impactors: d50=7.1, 5.4, 4.4, 3.7, 3.0, and 1.8 m
Simulation of Respirable Curve Using Impactors
Aerodynamic Particle Diameter, da, m
0 2 4 6 8 10 12
Pen
etr
ati
on
, P, %
0
25
50
75
100
HD Cyclone, QS=2.2 L/min
Respirable Convention
PPI, QS=2.0 L/min
Performance of SKC Parallel Particle Impactor
Performance of Individual Impactors of High Flow PPI
Performance of High Flow Parallel Particle Impactor
Experimental Setup
%100)(
)()(
dC
dCdE
Up
Down
Clean Air(50 Lpm )
VirtualIm pactor
ChargeNeutralizer
TurbulenceGenerators
Honeycom bFlow Straightener
Clear PlexiglassCylinder
(D=12 , H=48 )” ”
AccessPort
Foam
Sam plingLines
BallValve
TestDevice
To Filter
M akeup Flow
AerosolGenerator
Aerodynam icParticle Sizer
(APS 3320)
Inlet
Exhaust
ImpactionPlate
SKC Parallel Particle Impactor
SKC High Flow PPI
Conclusions
o High flow personal respirable sampler was developed and shown to match the entire ACGIH/CEN/ISO respirable curve closely.
o The newly developed respirable sampler in conjunction with a high flow personal sample pump can be used to accurately measure occupational exposure to respirable crystalline silica when new lower exposure limits need to be met.
Thank You!
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