Abstract  Occupational exposure to trichloroethylene (TRIC) and perchloroethylene (PERC) in metal degreasing is analyzed by calculating airborne concentrations for a large set of possible exposure scenarios (Scenario-Based Risk Assessment, SceBRA). Different types of degreasing machines ranging from open-top machines used until the 1980s to closed-loop nonvented machines used since the 1990s are investigated; the scope of the study is Germany. Concentrations are calculated for different kinds of releases (emissions from open baths, leakage, release of contaminated air during loading and unloading) with a dynamic two-box model for the near-field and the far-field. The concentration estimates are in good agreement with measured data. The airborne concentrations are compared to maximum workplace concentrations (MAK values). The full set of scenarios shows for which situations MAK values were exceeded and how the transition to newer degreasing machines reduced the occupational exposure by more than one order of magnitude. In addition, numbers of exposed workers are estimated for different years. While more than 25,000 workers in the near-field were exposed to TRIC and PERC in 1985, the number is below 3000 since 1996, which is mainly due to technology changes, rationalization, automatization, and replacement of TRIC and PERC by nonchlorinated solvents.

Abstract  Vehicle garages often contain high concentrations of volatile organic compounds (VOCs) that may migrate into adjoining residences. This study characterizes VOC concentrations, exposures, airflows, and source apportionments in 15 single-family houses with attached garages in southeast Michigan. Fieldwork included inspections to determine possible VOC sources, deployment of perfluorocarbon tracer (PFT) sources in garages and occupied spaces, and measurements of PFT, VOC, and CO(2) concentrations over a 4-day period. Air exchange rates (AERs) averaged 0.43+/-0.37 h(-1) in the houses and 0.77+/-0.51 h(-1) in the garages, and air flows from garages to houses averaged 6.5+/-5.3% of the houses' overall air exchange. A total of 39 VOC species were detected indoors, 36 in the garage, and 20 in ambient air. Garages showed high levels of gasoline-related VOCs, e.g., benzene averaged 37+/-39 microg m(-3). Garage/indoor ratios and multizone IAQ models show that nearly all of the benzene and most of the fuel-related aromatics in the houses resulted from garage sources, confirming earlier reports that suggested the importance of attached garages. Moreover, doses of VOCs such as benzene experienced by non-smoking individuals living in houses with attached garages are dominated by emissions in garages, a result of exposures occurring in both garage and house microenvironments. All of this strongly suggests the need to better control VOC emissions in garages and contaminant migration through the garage-house interface.

Abstract  1-Bromopropane (1-BP) is a solvent that is used in degreasing, dry cleaning, spray adhesives, and aerosol solvents. Occupational exposure to 1-BP has been linked to neurological illnesses. Animal studies show that 1-BP may also cause cancer and reproductive disorders. Controls and personal protective equipment are available to protect workers from 1-BP exposure. Exposure to 1-BP can cause irritation (for example, of the eyes, mucous membranes, upper airways and skin) and can damage the nervous system. Neurologic effects can appear as headaches, dizziness, loss of consciousness, slurred speech, confusion, difficulty walking, muscle twitching, and/or loss of feeling in arms and legs (Ichihara et al. 2012). These effects may continue among affected persons even after exposure to 1-BP has ended (Majersik et al. 2007). As with many other solvents, workers can be exposed to 1-BP by breathing in vapor or mists of spray. Workers might also be exposed if the chemical touches their skin because it can be absorbed (Hanley et al. 2006; Frasch et al. 2011). Additionally, the risk of health effects to workers increases the longer they work with or near 1-BP. Impacts on health have been seen in workers after exposures for as little as two days, although symptoms are more commonly associated with longer exposure (Ichihara et al. 2012). Federal OSHA does not currently have a specific exposure standard for 1-BP; however, employers are required by law to keep their workers safe from this recognized hazard. Degreasing, spray adhesive, aerosol solvent and dry cleaning operations expose workers to air concentrations of 1-BP greater than the limits set by the California Occupational Safety and Health Administration (Cal-OSHA) and the American Conference of Governmental Industrial Hygienists (ACGIH). California has adopted a 5 ppm (parts per million) time-weighted average PEL (permissible exposure limit) along with a skin notation which means that a worker's skin, eyes and mouth should be protected from any contact with 1-BP; this limit was based on reproductive and developmental toxicity (observed in animal studies) and technological feasibility assessments from industry (CA DIR 2009). ACGIH currently recommends a 10 ppm time-weighted average threshold limit value but has proposed lowering the value to 0.1 ppm (ACGIH 2013).

Abstract  On April 7, 2000, the National Institute for Occupational Safety and Health (NIOSH) received a confidential employee request for a health hazard evaluation (HHE) at Trilithic, Inc., in Indianapolis, Indiana. The request centered on health effects possibly associated with the introduction of a new solvent called NPB in the cold vapor degreaser. The solvent contained 1-bromopropane (1-BP, also called n-propyl bromide), which is commonly contaminated with 2-bromopropane (2-BP, isopropyl bromide). The NIOSH investigators conducted site visits on July 18, and November 8, 2000. During the latter site visit, 1-BP and 2-BP personal breathing zone and area air concentrations were measured to determine employees' exposures to these compounds when cleaning small parts in the cold vapor degreaser.