Exposure to fluoropolymers and VOCs during spray sealant product use.

Fluoropolymer based tile and fabric spray sealants were evaluated for the release of airborne fluoropolymer constituents and volatile organic compounds (VOCs) during typical product use scenarios in a simulated bathroom and a simulated recreational vehicle. Fluoride was quantified after oxygen bomb digestion of airborne spray collected from personal, area, and surface samples. VOCs were quantified by gas chromatography/mass spectrometry (GC/MS) and gas chromatography/flame ionization spectrometry (GC/FID). Tile grout sealant contained approximately 1% acrylic fluoropolymer resin and 90% VOCs not including propellants. VOCs were short- and medium- chain methylated isoparaffinic hydrocarbons. When horizontally spraying a bathroom shower floor, grout spray sealant released a non-detectable amount of fluoride (<0.8 µg/m3) and 400-1400 mg/m3 total VOCs. When vertically spraying a shower wall, up to 2.0 µg/m3 of fluoride and from 1000 to 2300 mg/m3 total VOCs were detected. Fabric spray sealant contained 1% acrylic fluoropolymer resin and approximately 90% VOCs including perchloroethylene (PERC). Fabric spray released from 0.5 to 2.3 µg/m3 fluoride inside a recreational vehicle in the absence of crosswinds and less than 0.5 µg/m3 fluoride in the presence of a 10 mph crosswind. VOC release measured 240-938 mg/m3 without crosswinds and 161-522 mg/m3 with crosswinds. These studies show that fluoropolymer constituents from fluorinated spray sealants were near non-detectable levels in the breathing zone in nearly all samples while VOCs were measured at elevated levels (>400 mg/m3). The toxicological consequences of elevated VOCs during sealant spraying and the effects of certain fluoropolymer constituents are discussed.

Emission of diacetyl (2,3 butanedione) from natural butter, microwave popcorn butter flavor powder, paste, and liquid products.

Diacetyl (2,3 butanedione), a butter-flavored diketone, has been linked to a severe lung disease, bronchiolitis obliterans. We tested a total of three natural butters and artificial microwave popcorn butter flavorings (three powders, two pastes, and one liquid) for bulk diacetyl concentration and diacetyl emissions when heated. Pastes and liquid butter flavors contained the highest amount (6% to 10.6%) while natural butter possessed up to 7500 times less diacetyl. All artificial butter flavors studied emitted diacetyl. Dry powders emitted up to 1.62 ppm diacetyl; wetted powders up to 54.7 ppm diacetyl; and pastes emitted up to 34.9 ppm diacetyl. The liquid butter flavor emitted up to 17.2 ppm diacetyl. Microwave popcorn flavoring mixtures emitted up to 11.4 ppm diacetyl. At least 93% of the dry powder particles were inhalable. These studies show that microwave butter flavoring products generate concentrations of diacetyl in the air great enough to endanger those exposed.

Zonolite attic insulation exposure studies.

Several studies were designed and conducted to evaluate amphibole asbestos exposures in homes containing Zonolite (expanded vermiculite) attic insulation (ZAI). A range of tasks selected for evaluation included cleaning, working around, moving, and removal of ZAI in attics and living spaces. The fieldwork for these studies was conducted at two homes in Spokane, WA and one home in Silver Spring, MD. Personal and area air samples were collected and analyzed as part of the exposure studies. Surface dust samples and bulk samples were also collected and analyzed. The results demonstrated that airborne concentrations of amphibole asbestos were not elevated if the material is undisturbed. The results also demonstrated that cleaning, remodeling, and other activities did produce significant concentrations of airborne amphibole asbestos when the ZAI was disturbed.

Fiber release during the removal of asbestos-containing gaskets: a work practice simulation.

Work practice studies were conducted involving the removal of asbestos-containing sheet gaskets from steam flanges. These studies were performed to determine potential exposure levels to individuals who have worked with these types of materials in the past and may still work with these products today. The work practices were conducted inside an exposure characterization laboratory (ECL) and were performed by scraping and wire brushing, chrysotile-containing (65% to 85%) sheet gaskets from a number of used steam flanges. Airborne asbestos levels were measured by phase contrast microscopy (PCM) and transmission electron microscopy (TEM) for the personnel and area air samples collected during the study. These workplace simulations showed substantial asbestos fiber release using scraping, hand wire brushing, and power wire brushing techniques during the gasket removal process. The range of concentration was 2.1 to 31.0 fibers/cc greater than 5 micrometers when measured by PCM. These results contrasted with the few reported results in the published literature where lower airborne asbestos levels were reported. In these studies the airborne asbestos fiber levels measured in many of the samples exceeded all current and historical Occupational Safety and Health Administration (OSHA) excursion limits (15-30 minutes) and some previous permissible exposure limits (PEL) based on eight-hour time-weighted average (TWA) standards. Also, individuals who performed this type of work in the past may have had exposures higher than previously suspected. The results demonstrated that employees who remove dry asbestos-containing gaskets with no localized ventilation should wear a full face supplied air respirator with a HEPA escape canister and the work area should be designated a regulated area.