john raper consultant forensic scientist understanding your client’s evidence asbestos products v...

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John RaperConsultant Forensic Scientist

Understanding Your Client’s Evidence

asbestos products v asbestos-free substitute products

SARAG – South Yorkshire Asbestos Victim Support GroupWORKING FOR ASBESTOS VICTIMS ACROSS SOUTH YORKSHIRE AND NORTH NOTTS

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Understanding Your Client’s Evidence:asbestos products v asbestos-free substitute products

Aims

• Understanding your client’s evidence• Principal uses of asbestos-containing materials• Evidence relating to exposure to asbestos• Exposure dose calculations

• Asbestos v asbestos-free products• Approach• Regulatory controls• Some examples

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Principal uses of asbestos-containing materials include:

• Thermal insulation (lagging)• Sprayed Coatings (e.g. limpet)• Asbestos insulation board (AIB)• Asbestos cement (AC)• Friction materials (e.g. brakes and clutches)

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Thermal insulation (lagging)

• 15 – 100% asbestos• Used up to the late 1960s /

early 1970s• All types of asbestos used• Mixed on site / pre-formed• Also includes rope, string,

yarn, mattresses and blankets

Image source – HSE

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Sprayed Coatings

• Up to 85% asbestos• Usually crocidolite (up to

1970)• Amosite and chrysotile up to

the cessation of use in 1974


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Asbestos Insulation Board (AIB)

• 16 – 40% asbestos (mainly amosite)

• Used from 1950s to circa 1980• Numerous construction uses

• Fire protection• Heat resistance• Partitions• Some ceiling tiles• General building board

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Asbestos Cement (AC)

• 10 - 15% asbestos (chrysotile)• Early 20th Century to 1990s• Numerous construction uses

• Corrugated and flat sheets• Moulded products

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Friction products

• Up to 50% asbestos (chrysotile) (as supplied)

• Majority converted to fosterite• Use up to the mid-1980s• Brake and clutch linings


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Other products include (but not limited to):

• Millboard• Fire blankets, gloves, protective clothing• Flooring materials• Textured coatings

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Evidence:

“I keep six honest serving-men(They taught me all I knew);Their names are What and Why and WhenAnd How and Where and Who.”

Rudyard Kipling – The Elephant’s Child (Just So Stories)

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Evidence:

• Industry• Nature of the exposure• Application of control measures

• Elimination• Engineering controls• Segregation• Clearing up – vacuums, wet methods• Ventilation control measures• Respiratory Protective Equipment• Information / Instruction / Training / Supervision

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Dose Calculation

• Nature of the exposure• Duration – hours per day• Calculated estimate of the 8-hour Time Weighted Average

(TWA) exposure• Extent of exposure – years• Asbestos dose – fibres / ml years

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Why consider if exposure was to an asbestos-free alternative?

• Regulatory controls• Industry / voluntary bans• Industries / situations where asbestos was not commonly used• Considering the actions the Defendant should have taken

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• The Asbestos Industry Regulations 1931

• The Asbestos Regulations 1969

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• Asbestos (Prohibitions) Regulations 1985 • ban on importation, use in manufacture and marketing of crocidolite

(blue) and amosite (brown) asbestos

• Asbestos (Prohibitions) Regulations 1992• ban on importation , supply and use of all amphibole asbestos• prohibit supply and use of certain products containing chrysotile

(white) asbestos

• Asbestos (Prohibitions) (Amendment) Regulations 1999• ban on importation , supply and use of all chrysotile asbestos• ban on trade in second hand products• some minor exemptions

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Alternatives - Some References• Engineering Equipment Users Association (Handbook No.33)

(1969) – Appendix III• Some industry, trade and independent research reports (1970s)• Selected written evidence submitted to the Advisory

Committee on Asbestos 1976-1977• Alternatives to asbestos products: A review (HSE) (1986)

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Engineering Equipment Users Association (Handbook No.33) (1969) – Appendix III• Lists commonly available alternatives• Notes alternatives not equivalent in all respects• No alternative? Consider treated asbestos products• Alternatives often more expensive• Notes poor heat + steam resistance of glass and rock wool

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Industry-specific documentation (1960s and 70s)• Industry never advocated wholesale removal of installed

asbestos• Alternatives evaluated and specified for new work

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Trade publications (1970s)• Tended to focus on the uses and attributes of asbestos

(maintain the status quo)• Alternatives to most asbestos-containing materials• Costs• Lack of adaptability inherent with the alternatives

• very high stock inventories• safety critical failings

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Independent Research (1970s)• Many (not all) applications can utilise alternatives• “substitution on health grounds often involves a penalty in cost

and performance”• Caution on possible unidentified health hazards from the

alternatives• Recognises that some residual use of asbestos will be necessary• Even if banned, legacy of existing installation will necessitate

education and strict enforcement

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Selected written evidence submitted to the Advisory Committee on Asbestos 1976-1977• Submissions from many manufacturers of asbestos products• Some manufacturers identified research into alternatives• Alternatives identified due to a perceived “shortage of supply”

of raw materials

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Alternatives to asbestos products: A review (HSE, 1986)• Independent review • Performance data only – health risks of alternatives not

considered• Technical feasibility of replacing asbestos

• Thermal insulation and dry packings• Textiles for heat and flame protection• Millboard• Electrical insulation• Friction materials• Bearings• Reinforced plastic composites• Building materials• Others

• List of suppliers

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Claimant’s description of asbestos exposure is unlikely when describing the use of asbestos after:

• 1970 use of crocidolite• 1974 sprayed asbestos dispersions • early 1980s use of AIB in construction• 1988 decorative textured coatings in construction

Some suppliers already voluntarily removed asbestos content

• 1999 use of asbestos products in the UK

Of course this doesn’t exclude exposure from disturbance of existing asbestos-containing materials

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General points on substitutes • Commonly available from 1960s • Early to mid-1970s – trade associations still promoting ACMs• Keen to point out costs of substitutes were higher than ACM• Independent assessment was rare• Focus upon the performance of the substitute – not the health

risks from that substitute• No universal replacement – would likely have the same health

hazard• Majority of substitutes suggested were glass or ceramic fibre

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John RaperConsultant Forensic ScientistPragma Asbestos Ltd2 Beacon WalkGringley on the HillDoncasterDN10 4TD

[email protected]

www.pragmaconsulting.net

(01777) 816506


john raper consultant forensic scientist understanding your client’s evidence asbestos products v...

Documents

asbestos chrysotile

asbestos victims

types of asbestos

friction products

materials evidence

flat sheets moulded

s early

s numerous construction