Asbestos. Dion Torhjelm, PEng Evan Alvernaz, CIH, ROH, CSP

Transcription

1 Asbestos Dion Torhjelm, PEng Evan Alvernaz, CIH, ROH, CSP

2 The Road Map History and Uses Health Effects Regulations Fire Prevention and Inspection Issues WorkSafeBC Initiatives

3 History and Uses

4 What is Asbestos? Fibrous rock found naturally in the Earth s crust Fibrils are very small and not visible to the human eye Used in thousands of building products

5 What is Asbestos? The hazardous effects of asbestos may have been recognized as early as the 1st Century AD. slaves wearing and weaving asbestos cloth Asbestosis - identified in 1920/1930. Link to lung cancer reported in the UK in 1934 firmly established in 1955 Link to mesothelioma - established in 1960

6 What is Asbestos? Found in the veins in host rock. The class of asbestos depends on the type of rock that form the asbestos

7 Common Types of Asbestos Serpentine Chrysotile Amphibole Amosite Crocidolite Tremolite Anthophyllite Actinolite

8 Serpentine Asbestos Chrysotile White Asbestos hydrated, magnesium silicate long, wavy and flexible fibres Accounts for about 90% of the current world consumption.

9 Asbestos Production Asbestos is extracted by open pit mining

10 Asbestos Production Areas of production: Canada (Chrysotile) The former Soviet Union USA China South Africa (Amosite) Australia (Crocidolite

11 Asbestos in Canada The majority of the world s chrysotile was mined in Thetford, Quebec.

12 In the News

13 In the News The Federal Government of Canada will no longer support the export of chrysotile asbestos or oppose the registration of chrysotile as a hazardous substance under the Rotterdam Convention. The PQ in Quebec will rescind the $58 M loan guarantee approved by the Quebec Liberals to ramp up the asbestos industry in Quebec (Jeffrey and Thetford Mines). The leader of the Liberal party in Quebec, Jean Charest, is from Sherbrooke, in the heart of the asbestos belt. He lost his seat during the last Provincial election.

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15 Useful Properties Resists burning. High tensile strength. Dampens noise. Resists corrosion. Resists biological growth. Insulates against the conduction of electricity.

16 Asbestos Containing Building Materials Exteriors asbestos cement materials felts and mastics stucco brick and mortar insulation

17 Asbestos Containing Building Materials Ceilings t-bar ceiling tile cement ceiling tile acoustic and stippled finishes plaster or drywall joints

18 Asbestos Containing Building Materials Walls plaster drywall joints stippled finishes thermal spray cement panels

19 Asbestos Containing Building Materials Flooring vinyl asbestos tile (VAT) sheet vinyl flooring floor leveling compounds

20 Miscellaneous ACM Incandescent light fixture backing Wire insulation Fume hoods Lab counters Elevator brake shoes Heating cabinet panels Fire dampers and flanges Diffuser back-plaster Emergency generators Fire-stopping Theatre curtains Welding blankets and screens Incinerators Cooling towers Duct tape Duct isolation joints

21 Industrial Uses Pipe insulation Insulating blocks Sprayed insulation Condensation control Roof shingles Asbestos cement board and pipe (Transite) Caulking compounds Floor tiles Joint cements Welding rods

22 Pipe or Boiler Insulation Asbestos-containing material (ACM) was often used as thermal mechanical insulation. Can be pre-formed insulation sections, blocks or mudding compounds. Often used with fiberglass insulation.

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24 Health Effects

25 Fatal Injuries and Diseases ( ) Motor Vehicle Accidents 313 Other Injuries 620 Asbestos Diseases 465 Other Occupational Diseases 155 Total 1,553

26 Accepted Fatal Claims for Asbestos and Silica ( )

27 What is an Asbestos Fibre By definition, an asbestos fibre is longer than 5 μm and has a length to width ration greater than 3:1

28 Fibre Breakage Man-made fibres such as fiberglass cannot be split along their length, but instead become shorter when broken down. When disturbed, an asbestos fibre can be split into thinner and thinner fibres.

29 Fibre Diameter Fibre Type Average Diameter (Microns) human hair 40 mineral wool 7 fibreglass 1-25 chrysotile amosite 0.4 crocidolite 0.2 ceramic refractory fibre 2-3

30 Health Hazards Asbestos fibres are hazardous when inhaled. Asbestos fibres can remain airborne for several hours. The smaller the fibre, the longer it takes to settle. Fibre-related disease can result.

31 Natural Defenses Mucociliary elevator: mucus and hair-like cilia lining the upper respiratory tract. Macrophages: cells surrounding the deep lung spaces.

32 Mucociliary Elevator Particles become trapped in the mucous lining and are swept upwards by the tiny hair-like cilia. Once the mucous with trapped particles reaches the back of the throat it is coughed out.

33 Macrophages Macrophages surround and break down foreign particles and keep the air sacs of the lungs clear. Macrophages will try to get rid of asbestos fibres by spilling enzymes, but since asbestos is virtually indestructible, the fibers cannot be destroyed. The fibres will remain in the lungs.

34 Macrophages Macrophages will continue to die trying to dissolve asbestos fibres, resulting in continuous scar tissue buildup. The more fibres trapped, the longer the time, the greater amount of scar tissue. Different people develop scar tissue at different rates

35 Asbestos-Related Diseases Asbestosis Lung cancer Mesothelioma Pleural thickening

36 Asbestosis Asbestosis is a serious scarring condition of the lung that normally occurs after heavy exposure. The disease is progressive. As the amount of scar tissue increases, the lungs become more rigid, making it difficult to breathe. Air transfer in the lungs is decreased due to the scar tissue. In severe cases can be fatal.

37 Lung Cancer Typically, cancer from asbestos exposure does not develop until 20 or more years after first exposure. Lung cancer represents 5-15% of asbestos related lung problems.

38 Lung Cancer Asbestos exposure, combined with smoking, increases the risk of lung cancer as much as 70 times. Asbestos Only Smoking Only Asbestos & Smoking Increased Chance of Lung Cancer

39 Mesothelioma Mesothelioma is a cancer which affects the lining of the lungs (pleura) and the lining surrounding the lower digestive tract (peritoneum). It is almost exclusively related to asbestos exposure. It is extremely rare and always fatal, usually within months of diagnosis. A dose response relationship has not been identified.

40 Mesothelioma Length of exposure to asbestos in mesothelioma patients ranges from two months to 50 years. The period between exposure and disease onset ranges from 15 to 55 years, with an average of 40 years before disease development.

41 Pleural Thickening Pleural thickening is generally a problem that happens after heavy asbestos exposure. The lining of the lung (pleura) thickens and swells. If this gets worse, the lung itself can be squeezed, and can cause shortness of breath and discomfort in the chest.

42 Regulations

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44 Asbestos Inventory An employer must ensure that a qualified person has prepared an inventory of asbestos containing materials in the workplace. The inventory must be kept current and must be available.

45 Definition of Asbestos Containing Material The Occupational Health and Safety Regulation defines asbestos-containing material as: Containing 0.5% or more asbestos as determined by polarized light microscopy, electron microscopy, and/or gravimetric analysis Vermiculite-containing insulation materials which contain any asbestos even less than 0.5%

46 Sample Analysis Methods currently accepted by WorkSafeBC for bulk sample analysis include: NIOSH Method 9000 (Chrysotile by XRD) NIOSH Method 9002 (PLM) EPA Method 600/R-93/116 (PLM, point counting and TEM) EPA Method 600/R-03/004 (for vermiculite)

47 Sample Analysis To quantify asbestos percentages below 0.5%, the following procedures should be used (refer to EPA/600/R-93/116): 400 point count plus gravimetric reduction 1000 point count Analytical TEM plus gravimetric reduction

48 Control of Asbestos Fibre An employer must ensure that all friable asbestos-containing materials in the workplace are controlled by removal, enclosure or encapsulation The employer must not allow any work that would disturb asbestos-containing material unless necessary precautions have been taken to protect workers.

49 Risk Assessment and Work Procedures An employer must ensure that procedures for handling or using asbestos-containing material prevent or minimize the release of airborne asbestos fibres. The employer must ensure that the procedures for the control, handling or use of asbestos are in accordance with procedures acceptable to the Board.

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51 Risk Activity Definitions Low risk work activity A work activity that involves working with or in proximity to asbestos-containing material, if the material is not being cut, sanded, drilled, broken, ground down or otherwise fragmented, or otherwise disturbed. High risk work activity A work activity that involves working with or in proximity to asbestos-containing material if a high level of control (e.g. air-tight enclosure) is necessary

52 Risk Activity Definitions Moderate risk work activity A work activity, other than a high risk work activity, that involves working with or in proximity to asbestos-containing material that is being disturbed

53 The Qualified Person The following must be performed by a qualified person : Risk Assessment Inventory Work procedure development Inspect sites for hazardous materials prior to demolition or renovation (section )

54 Who is Qualified CIH, ROH ROHT, CSP, CRSP, P.Eng + experience and training Or, other acceptable combination of education, training and experience.

55 Exposure Control Plan a. Purpose & Responsibilities b. Risk Assessment & Control c. Education and Training d. Written Work Procedures e. Hygiene Facilities f. Health Monitoring g. Documentation

56 Hazardous Materials Section of the OHS Regulation states: Before work begins on the demolition or salvage of machinery, equipment, buildings or structures, the employer or owner must a) inspect the site to identify any asbestos, lead, or other heavy metal or toxic, flammable or explosive materials that may be handled, disturbed or removed, b) have the inspection results available at the worksite, including any drawings, plans or specifications, as appropriate, to show the locations of any hazardous substances, c) ensure that any hazardous materials found are safely contained or removed, and d) if hazardous materials are discovered during demolition work that were not identified in the inspection required by paragraph (a), ensure that all work ceases until such materials are contained or removed.

57 Fire Prevention and Inspection Issues

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60 Fire Fighting and Investigations Some municipalities have implemented asbestos exposure control plans for fire fighters and investigators

61 Fire Prevention and Inspections Asbestos can reasonable be expected in buildings constructed prior to 1990 If damaged suspect materials are identified, a cautious approach should be taken The Board has received calls from individuals concerned about the potential presence of asbestos containing materials

62 WorkSafeBC Initiatives

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68 Questions?