Asbestos Sampling

Presenter:

Gabriel Mizan (NIOH)

DoEL Asbestos Abatement Regulations Launch 27 November 2020

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)

• 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)

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

• 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

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)

Sampling Asbestos Enclosure

Enclosure size Number of samples

Area (m2) Volume (m3)

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)

Sampling Equipment

• Spray bottle and detergent

• Core sampler

• Knife, scraper, pliers

• Hand drill

• Camera

• Plastic bags, bottles, sealable containers

• Data capturing form

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

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