Transcript MWFs Study An Evaluation of Analytical Methods, Sampling

Occupational Exposure to Metalworking
Fluids
Presented at the Occupational
Hygiene Association of Ontario
Spring Symposium
March 28, 2007
By Lorraine Shaw, B.Sc., CIH, ROH
Occupational and Environmental
Health Laboratory,
McMaster University
Outline

Overview

Types of MWF, Health Effects, Standards,
Exposure Assessment

Objectives of the Study
 Methodology


Results


Selection of Plants, Laboratory Investigation,
Field Investigation, QC and Statistics
Laboratory and Field Results
Conclusions
Overview (I)
Types of MWFs:
 Oil-based:
Health Effects:
 Cancer
– Insoluble (neat)
 Hypersensitivity
– Soluble (30% - 85% oil)
Pneumonitis (HP)
 Water-based:
 Respiratory Effects
– Semi-synthetic (5%-30%  Dermatitis
oil)
– Synthetic (no oil)
Overview (II)
Regulations and Exposure Standards:
Ontario Ministry of Labour:
Oil, mineral, mist 5 mg/m3 TWAEV, 10 mg/m3 STEV
ACGIH TLV-TWA (Mineral Oil) in 2006 notice of intended changes :
Mineral Oil Used in metal working
Poorly and mildly refined 0.2 mg/m3 (Inhalable)
A2
Highly and severely refined 0.2 mg/m3 (Inhalable)
A4
Proposed NIOSH REL for all types of MWF (1998):
0.5 mg/m3(Total)
0.4mg/m3 (Thoracic)
Exposure Assessment:
–
–
Sampling Devices:
ie. Total, Thoracic (BGI), IOM, Direct Reading Instrument
(DustTrak)
Particle size selective sampling
The Three Size Fractions
Objectives

Assess and Validate Analytical Methods
 Assess Air Sampling Methods
 Collect Current Representative Occupational
Exposure Data
 Assess Exposure Exceedance
 Compare Ontario Exposure with Published Data
(Mainly Water-Based MWF’s)
Methodology

Selection of 4 Plants in Ontario
 Laboratory Investigation
 Field Investigation
 Quality Control and Statistical Analysis
Laboratory Investigation
NIOSH Method (0500) – Total Aerosol
 NIOSH 5524 – Extractable MWFs
 HSE Method (MDHS 95) – Marker Element


Sample Recovery
 Detection Limits
 Sample Stability During Storage
Field Investigation

Collection of Air Samples
– Personal
– Area

Size Selective Samples
–
–
–
–
–
Total
Thoracic
(MMAD = 10 µm)
Respirable (MMAD = 4 µm)
Inhalable
(MMAD = 100 µm)
Direct Reading Instrument (DustTrak)
Air Sampling Devices
Total Sampler
DustTrak Aerosol Monitor
Direct Reading Instrument
BGI 2.69 Cyclone
Thoracic Sampler
IOM Inhalable Sampler
Respicon Size-Selective
Particle Sampler
Occupational Exposure
Examples of Machining Fluids
Examples of Finished Products
QC and Stats

QUALITY CONTROL
– Laboratory
– Field

STATISTICAL ANALYSIS
– Excel and Minitab 13
Results: Laboratory Investigation

Sample Recovery
– Our Study
– NIOSH Study

83.5%
95 %
Detection Limit
– Our Study
– NIOSH Study
35µg
28 µg
 Storage Study (Sample Stability)
– Room Temp – NOT Stable
– Refrigerator – 2 days
– Freezer – 7 days
Results:Airborne Concentrations (mg/m )
3
N
GM
Min
Max
Standard
Observed
Exceedance
Total Aerosol
5
0.59
0.25
3.28
0.5
40%
Total Extractable Aerosol
5
0.33
0.17
1.05
0.5
20%
Thoracic Aerosol
50
0.33
0.06
1.09
0.4
38%
Thoracic Extractable
Aerosol
50
0.22
0.06
0.88
0.4
26%
Total Aerosol
168
0.39
0.04
3.84
0.5
37%
Total Extractable Aerosol
168
0.27
0.04
3.47
0.5
21%
Thoracic Aerosol
151
0.32
0.04
1.79
0.4
39%
Thoracic Extractable
Aerosol
151
0.22
0.04
1.43
0.4
24%
Sampler Description
Personal Samples
Area Samples
• % Exceedance is based on log normal distribution
ze = -log(GM/STD) / log(GSD)
Relationship of Total vs Thoracic
2.0
Thoracic Aerosol (mg/m3)
Thoracic Aerosol = 0.72 * Total Aerosol
n = 122
1.5
1.0
0.5
0.0
0.0
0.5
1.0
1.5
Total Aerosol (mg/m3)
2.0
2.5
Conclusions (I)

HSE method proved problematic
 Both NIOSH method 0500 or 5524 can be used
 preferred method is the 5524
 Detection limits, sample recovery etc. were
similar to NIOSH study
 Samples should NOT be stored at Room Temp
 Samples should be analyzed within 2 or 7 days
depending on storage temperature
Conclusions (II)

Ratio of Thoracic to Total aerosol is about 0.7
 Range of exposures in Ontario (0.04 to 3.84
mg/m3) is similar to others (NIOSH & OSHA)
 Percent exceedance based on data set and
assumption of log normality is 38% with
respect to NIOSH REL
 Respiratory effects reported at levels below 0.5
mg/m3
 Total Protection requires AIR, DERMAL and
FLUID management
Thank you
This research study was
funded by a grant from
the WSIB