asbestos sampling · 2020. 11. 30. · hsg248 asbestos: the analysts’ guide for sampling,...
TRANSCRIPT
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Asbestos Sampling
Presenter:
Gabriel Mizan (NIOH)
DoEL Asbestos Abatement Regulations Launch 27 November 2020
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Regulatory Requirements
Air monitoring (personal and environmental sampling) for asbestos must be done:
• In case of type 2 and 3 asbestos work
• Performed by an AIA
• Carried out following HSG248*
• Representative of worker’s exposure
• Carried out at a frequency determined by the AIA and based on risk assessment
• Results compared to OEL (or STEL)
• Asbestos monitoring to be conducted after consultation with H&Sreps / committee
*HSG248 Asbestos: The analysts’ guide for sampling, analysis and clearance procedures (HSE, UK)
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• Determine compliance with OEL
• Verify effectiveness of control measures
• Assess suitability of RPE
• Leakage testing
• Background
• Clearance
Why Sample for Asbestos?
HSG248 Asbestos: The analysts’ guide for sampling, analysis and clearance procedures (HSE, UK)
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Types of Sampling and Regulated Limits
Type of Sampling Purpose Regulated Limit
Personal (exposure)
Determine compliance with OEL / STEL
0.1 f/ml (OEL)0.6 f/ml (STEL)
Environmental (Area / Static)
• Test controls • RPE suitability• Leakage• Background
Clearance Confirm that an area is suitable for reoccupation
0.01 f/ml
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• Filter: Mixed cellulose ester (MCE)
• D = 25mm, pore size: 0.8-1.2 µm
• Open-faced filter holder
• Electrically conducting cowl
• Constant flow sampling pump (±5%)
• Flexible tubing
Sampling Equipment
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Sampling Strategy
Type of sampling
Sampling flow rate
(litre/min)
Minimum volume (litres)
Minimum No. of Graticules
counted
Airborne concentration
at LoQ(fibre/ml)
Personal Exposure / Compliance
OEL (4-hr) 1 240 100 0.04
STEL (10 min) 4 40 100 0.24
Area / Static / Environmental sampling
Clearance 1 – 16 480 200 0.01
Background 1 – 16 480 200 0.01
Leak 1 – 16 480 200 0.01
HSG248 Asbestos: The analysts’ guide for sampling, analysis and clearance procedures (HSE, UK)
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Sampling Asbestos Enclosure
Enclosure size Number of samples
Area (m2) Volume (m3)
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Bulk Asbestos Sampling
Bulk asbestos sampling is carried out to:
• Determine whether a material contains asbestos
• Determine the type of fibre/s in an ACM
• Comply with the Regulations with regard to identifying, assessing labelling and recording ACMs (asbestos inventory)
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Sampling Equipment
• Spray bottle and detergent
• Core sampler
• Knife, scraper, pliers
• Hand drill
• Camera
• Plastic bags, bottles, sealable containers
• Data capturing form
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Collecting a Bulk Asbestos Sample
• Minimize fibre release (dust)• Representative samples• Use appropriate PPE• Cause least damage• Avoid cross-contamination• Place sample into suitable sealable
container• Sample points should be repaired /
sealed • Locations accurately recorded and
labelled • Samples uniquely identified
Core CutterSource: Gully Howard Technical Ltd
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Asbestos Analysis Methods
Method Characteristics Used for
Polarised light microscopy
(PLM)
• Qualitative
• Low cost
• Quick
Fibre identification in bulk material
Electron microscopy (EM)
• High sensitivity
• Very expensive
Environmental and research studies
Phase contrast microscopy (PCM)
• Less expensive
• Relatively quick
• Regulated
Asbestos exposure measurement