Asbestos exposure during an abatement project

Our plain-English summary of Asbestos exposure during an abatement project, by D.E. Welsh (Journal of Occupational and Environmental Hygiene, 2007).

The study

• Author: D.E. Welsh
• Journal: Journal of Occupational and Environmental Hygiene
• Published: 2007;4(2):D7-9
• Cited by: 2 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

In plain English

This article reports one workplace inspection by the U.S. Occupational Safety and Health Administration (OSHA). An OSHA compliance officer wrote it, and it is not a research study. After a referral from the Rhode Island State Department of Health, OSHA inspected the removal of sprayed-on insulation from a former military test facility. The insulation was reported to be about 80% asbestos (40% chrysotile and 40% amosite). Nine workers were scraping it off walls and ceilings. It was only partly wetted, no surfactant was used, and the employer had done no personal air monitoring. OSHA sampled two workers. Their 8-hour time-weighted average exposures were 3.2 and 5.6 fibers per cubic centimeter of air (f/cc), which is 32 and 56 times OSHA's 0.1 f/cc permissible exposure limit. Unsampled time in the shift was counted as zero exposure. OSHA found the ventilation, decontamination area, respirators and fall protection inadequate, and it issued citations and assessed penalties. The author concluded that thorough wetting with surfactant, immediate HEPA vacuuming, removing ceiling material onto staging, and enough negative-air ventilation could have significantly reduced the exposures.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Report of a single OSHA compliance inspection (workplace case report with personal air sampling), published in an OSHA Compliance Issues column; not a research study
• Who was studied: Nine employees removing sprayed-on asbestos insulation inside the containment area at a large former military test facility, referred to OSHA by the Rhode Island State Department of Health. Two of the employees had personal air monitoring. The inspection date is not given.
• Exposure: Removal by hand scraping of sprayed-on asbestos-containing plaster/insulation, reported in poor condition and 2 to 3 inches thick, covering about 48,000 square feet of walls and ceiling. State health department bulk samples reported approximately 80% asbestos: 40% chrysotile and 40% amosite.
• Main results:
  • The first sampled employee had an 8-hour time-weighted average asbestos exposure of 3.2 f/cc. The article states this was 32 times the PEL.
  • The second sampled employee had an 8-hour time-weighted average exposure of 5.6 f/cc.
  • Both employees' 8-hour averages exceeded the OSHA permissible exposure limit of 0.1 f/cc. The second employee's exposure was 56 times the PEL.
  • In calculating the 8-hour averages, exposure during unsampled periods of the shift was assumed to be zero.
  • Individual samples ranged from 2.6 to 5.3 f/cc for the first employee (three samples) and from 6.0 to 10 f/cc for the second employee (three samples). The highest single sample was 10 f/cc, collected over 141 minutes.
  • Before OSHA's sampling, the employer had conducted no personal air monitoring.
  • The insulation was only partially wetted with a pressure washer, without surfactant. The wetting did not appear to fully penetrate the material, which the author said created a greater potential for airborne asbestos.
  • Four air changes per hour required 5,689 cubic feet per minute of exhaust. The single negative pressure unit was rated at about 2,000 cubic feet per minute, so at least three more machines were needed.
  • The decontamination area was a single room, not the required three-stage equipment room, shower and clean room.
  • Employees wore N-99 half-mask elastomeric respirators. OSHA found that supplied-air respiratory protection should have been used.
  • The employer was in compliance with asbestos hazard training, respirator training and fit testing, and medical surveillance requirements.
  • The compliance officer noted that on the sampling day the workers appeared more diligent in applying water than on the previous day.
  • The employer was issued citations and assessed penalties. It later provided documentation that the violations had been corrected.
• The authors' conclusion: The author stated that four procedures the employer did not use could have significantly reduced the observed exposures: enough surfactant applied long enough to fully wet the insulation; immediate HEPA vacuuming of waste; removing ceiling asbestos onto staging rather than letting it fall 18 feet to the concrete floor; and sufficient negative air ventilation.

Topics

Medical terms in this study, explained in our Lexicon: Asbestos Exposure, Abatement.

Related studies

• Personal and static sample measurements of asbestos fibres during two abatement projects — A. Dufresne, C. Dion, et al. (2009)
• Exposure to airborne asbestos during abatement of ceiling material, window caulking, floor tile and roofing material — J.H. Lange, S.L. Sites, et al. (2008)
• Exposure to airborne asbestos during abatement of ceiling material, window caulking, floor tile, and roofing material — J.H. Lange, S.L. Sites, et al. (2006)
• Asbestos abatement in a location previously improperly abated — J.H. Lange, S.L. Sites, et al. (2006)
• Personal airborne asbestos exposure levels associated with various types of abatement — J.H. Lange, K.W. Thomulka, et al. (2006)
• Safety and health of heavy equipment operators at Ground Zero — B.E. Lippy (2002)

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