A Canadian Perspective on Asbestos Precautions for the Removal
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A Canadian Perspective on Asbestos Precautions for the Removal of Drywall with Asbestos-Containing Drywall Joint Compound (ACDJC) Presented By Dr. Don Pinchin Pinchin Environmental May 28, 2011 1.855.PINCHIN pinchin.com Engineering Environmental and Health & Safety Solutions Pinchin Group of Companies Environment, Health and Safety consultants Founded in 1981 Four firms across Canada Major service areas: Hazardous materials in buildings Indoor air quality/mould Environmental management Building envelope consulting Occupational health and safety Air emissions control Green House Gas 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. Presentation Topics 1.855.PINCHIN Background on asbestos-containing DJC Regulatory Standards and enforcement What are the economic consequences? What are the real risks of ACDJC? What can renovation contractors do? pinchin.com © Pinchin Environmental Ltd. Background to the use of Gypsum Board (Drywall) in Construction Sackett board (felt facing on Plaster of Paris core) developed in the 1880s. Modern gypsum board (“drywall” as opposed to plaster or “wet wall” construction) developed as a ready to finish board by 1916 by US Gypsum. Joint treatments to provide a smooth finish were developed in the 1920s however most of the early drywall was used unfinished as backing board or lathe. Finished drywall partitions became commonplace after 1945 with the increase in mass produced housing. 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. Asbestos-Containing Drywall Joint Compound (DJC) Joint treatments (mud, joint compound or mastic) normally contained chrysotile asbestos along with gypsum, quartz, mica, clay, ground limestone and polymer additives. These were used with paper tape. Asbestos content is most commonly 3% to 6% but was higher in some earlier formulations. Overall asbestos content of the composite wall system is about 0.25% (including the weight of board). Although the phase out of asbestos in DJC started in the 1970s, it was not banned in Canada until 1980 and was used until at least 1982 in Canada. 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. Current Canadian Regulations related to Drywall Removal. Classification of drywall removal is not consistent. Most provinces (NS, NB, PEI, QC, MB, SK) class removal as Low Risk or Type 1 (normal dust control). NFLD, ON, AB, BC class large scale removal as Type 2 (Moderate Risk). In BC drywall removal overhead also requires a shower to be installed (Modified Moderate Risk). Ontario changed the classification from Type 1 to Type 2 as of November 2005. 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. Current Canadian Enforcement of the Drywall Removal as ACM. Enforcement is very inconsistent across Canada BC provides consistent enforcement of asbestos regulation including single family residential – a dedicated WorkSafe BC residential inspection group. The regulation in Ontario, Alberta, and NFLD is enforced in commercial/industrial/institutional by consultants, contractors and the regulator Residential work is beginning to be enforced in NFLD (bylaw in St. John’s pre-demolition) but as far as the author is aware is not enforced residentially in Ontario or Alberta unless the regulator is notified. 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. Changes to the Ontario Regulation Affecting Drywall Removal Formerly (O. Reg 838/90) classed removal of all drywall with ACDJC as a Type 1 Operation. New Ontario Reg. 278/05 states (Section 12 (2) 4) “The following are Type 2 operations: Removing one square metre or more of drywall in which joint filling compounds that are asbestoscontaining material have been used.” Note the area (one square metre) refers to the drywall not just the ACDJC 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. What does a Type 2 Operation mean in your building with respect to drywall (gypsum board) removal? 1.855.PINCHIN pinchin.com Engineering Environmental and Health & Safety Solutions Preparation of Work Area Drop sheet mandatory for Type 2 projects. Dust enclosure is required to control the spread of dust during Type 2 removal. Likely necessary for all Type 2 work. 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. Drywall Removal -Signage Asbestos warning signs are mandatory for more than 1 square metre (Type 2). 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. Dust Suppression and Personal Protection Wetting agent (amended water) mandatory for removal of drywall with ACM. Suit and respirator are mandatory for all Type 2 work (including drywall removal). 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. Removal Work Practices Removal of drywall following Type 2 work practices will require the practices seen here : disposable suit, respirator, signs, drop sheet, amended water, isolation of the HVAC system and an enclosure. 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. Drywall Waste Handling Drywall / ACM must be disposed of in asbestos waste containers as defined in the regulation. Note that this conflicts with Ontario Ministry of the Environment policy and eliminates the potential for recycling which has been common in the industry. 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. Clean-up of Work Area HEPA vacuum clean or wet clean fallen material on drop sheets and in the remaining floor channel. Drop sheets must be cleaned, wetted and disposed of as asbestos waste. Barriers must be treated similarly (unless rigid and cleanable). 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. Worker Clean-up Worker cleans and removes suit first for disposal (can be cleaned and re-used but this is not common), keeping respirator on face. Worker then washes hands and face and maintains respirator. 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. What Are the Economic Consequences? ACDJC was universally used on drywall from the earliest days until 1977. From 1977 to the early 1980’s ACDJC was phased out; starting in the U.S. ACDJC was formally banned in Canada (by the Hazardous Products Act) in 1980 but continued in use until at least 1982 (based on our testing). Pinchin performed the following analysis for Ontario building owners in 2007. 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. How Much Drywall with ACDJC was installed in Ontario? Pinchin obtained data from 1968 to 1980 from the Gypsum Association and the Canadian Manufacturing Yearbook. Approximately 7 Billion square feet of drywall was manufactured in Ontario in this period (data has not been collected from other provinces). No data exists on the quantity manufactured prior to 1968 or on the amount of drywall already removed as part of prior renovations. We have assumed these quantities are equal (a major assumption!). 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. What are the Cost Consequences? Data was collected from contractors and consultants to obtain the cost premium per square foot of drywall (not just floor area of the building) to remove and dispose of drywall following Type 2 procedures versus Type 1 procedures. The numbers are extremely variable particularly for residential. Residential Pre-Demolition Residential Renovation Office/Commercial 1.855.PINCHIN pinchin.com $2-$4/ft² >$4/ft² $1-$2/ft² © Pinchin Environmental Ltd. What are the Cost Consequences? (continued) Construction Cost impact therefore is likely to be over $15 Billion in Ontario alone if it is enforced. For residential demolition this adds about $12,000 to $15,000 for a typical home demolition in Ontario but this cost is as low as $7,000 in NFLD recently. This does not include any costs for testing, design, tenant relocation due to asbestos concerns, schedule impacts or long term management costs until the drywall is removed. 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. Why Pinchin thought that Type 2 procedures may be unnecessary 1. There is a very low asbestos content overall in drywall with ACDJC. On average it is around 0.2% to a maximum of 0.3% (based on 5% asbestos in the DJC and 3% DJC on the drywall). (non-asbestos for disposal purposes) 2. The ACDJC is very hard, quite dense, adhered to drywall one side and usually painted on the other side. It is not very friable (does not crumble or release fibres to the air during removal) due to the use of latex in the original formulation. 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. Why We Believe it is Unnecessary (continued) 3. Historical data from the Occupational Disease Information and Surveillance System 19962005 shows 253 allowed fatality claims from asbestos in construction. Of these 253 allowed claims only 3 painters who actively sanded this material to a smooth finish were included. 4. Recent testing (some of which follows) confirms little or no asbestos fibres are released from the drywall during normal interior demolition. 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. Testing to Determine Airborne Asbestos Exposure in Drywall Removal The Pinchin Group has performed testing in Newfoundland and Ontario which (in our opinion) conclusively indicates Type 2 precautions are unnecessary. Data was originally collected from June 2005 and submitted to the Ontario MOL December 2005. Since the Ontario Regulation was amended we have continued to obtain test results from various building types. There has been little or no response from regulators. 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. Test work performed to remove Drywall with ACDJC in totally sealed enclosure 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. Worst case scenarios simulated by saw cutting waste across joints to small pieces (totally dry) 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. Material bagged and area wet cleaned 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. Air Testing Methods and Results Average results of Personal samples (5) and Area sample in work area (1) analyzed by PCM (NIOSH 7400) and TEM (NIOSH 7402). PCM Result (f/cc) (NIOSH 7400) TEM Result (f/cc) (NIOSH 7402) PERSONAL 2.28 All below the limit of detection (<0.030) AREA 0.33 Below the limit of detection (<0.004) Sample type 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. Why the Different Results? The analysis by PCM detects all airborne fibres that meet a specific shape, length, width and aspect ratio. The PCM method does not identify what the fibres are and some gypsum crystals are counted as “asbestos” fibres. The TEM method counts only asbestos fibres of the same size and shape criteria. The conclusion is that virtually all the airborne fibres are not asbestos and that the removal of ACDJC does not produce any significant level of airborne asbestos. 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. Test Procedures (Construction site #1 – urban shopping centre) Work area – interior corridor, not accessible to employees, Ventilation turned off and isolated, no negative pressure, Workers used Type 2 (moderate risk) procedures, Hand tools to break and tear down drywall, Amended water used sparingly for dust suppression during breaking of drywall, Waste transported from the area in covered bins but disposed of as non-asbestos waste. 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. Air Testing Methods and Results Average results of Personal samples (5) and Area samples in work area (2) analyzed by PCM (NIOSH 7400) and TEM (NIOSH 7402 and ISO 10312). PCM Result (f/cc) (NIOSH 7400) TEM Result (f/cc) (NIOSH 7402) TEM Result (s/cc) Structures >0.5µm (ISO 13012) PERSONAL 0.41 All below the LOD (<0.03) 0.09 AREA 0.42 Both below the LOD (<0.01) 0.05 Sample type 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. Other test sites in Ontario and Newfoundland and Labrador Field testing of many sites (over 20) by Pinchin has NEVER shown any asbestos fibre levels in the work area above 0.01 f/cc even during the actual removal work using NIOSH Method 7402. This means that the work site is cleaner, even during the removal work, than the cleanliness required to clear or approve a Type 3 site for the entry the general public in every Canadian jurisdiction. We have never seen any results which indicate that ACDJC removal produces hazardous levels of asbestos 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. Confirmatory Results Using Joint Mastic used in the US. Published results (Perkins and Hargesheimer (2002)): None of their tests (laboratory, controlled demolition or normal uncontrolled demolition ) indicated significant amounts of airborne chrysotile fibres. None of their tests on DJC (including deliberate dustproducing work) caused any worker exposure near the Permissible Exposure Limit. The only testing that has any validity in determining the exposure of workers to airborne asbestos is the use of the TEM (they used NIOSH 7402). 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. Why is Drywall Removal still Type 2 – a personal opinion of Don Pinchin Historical concern over the testing of the 1970s which used the PCM and included non-asbestos “fibres” but indicated an asbestos disease risk in drywallers (was this possibly due to other exposure in construction of that era?). General risk avoidance orientation of health and safety professionals and workers towards asbestos. The inertia of regulators and the need to reverse a regulation which has cost many millions of dollars to building owners to date (but which will cost many billions more if not corrected). Drywall removal has become a major and profitable part of the asbestos removal industry. 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. What can Renovation/Drywall Contractors do? How good are your connections to the various Ministries of Labour? What pressure can you exert? The result will depend entirely on the province – likely no change will result in BC. Change in Ontario is possible in my opinion but not likely. On some sites in Ontario Pinchin have used test data to show Type 2 precautions are not necessary and relaxed precautions to produce significant savings (Section 23 – Equivalency). In the meantime you must obey the regulations or risk work shutdowns and fines. 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd. Questions? Dr. Don Pinchin dpinchin@pinchin.com For more information: www.pinchin.com 1.855.PINCHIN pinchin.com © Pinchin Environmental Ltd.
