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Surface contamination and skin exposure to aliphatic isocyanates in auto body shops: a quantitative assessment.

Liu Y; Stowe M; Walsh F; Sparer J; Cullen M; Holm C; Redlich C; Youngs F; Bello D; Woskie S; Boeniger M
American Industrial Hygiene Conference and Exposition, June 2-7, 2001, New Orleans, Louisiana. Fairfax, VA: American Industrial Hygiene Association, 2001 Jun; :39
Little has been done to quantify surface contamination and skin exposure to aliphatic isocyanates in auto body shops and to evaluate the effectiveness of personal protective equipment (PPE). The purpose of this study was to quantitatively evaluate such contamination and exposure in 20 shops that participated in a large epidemiological study on isocyanate asthma. Surfaces from mixing and painting tools and PPE (gloves and respirators) were wiped with a 16 cm2 polypropylene glycol moistened pad. The size of areas wiped was recorded. The pad was immediately placed in a vial containing 1-(9-anthracenylmethyl) piperazine in methylene chloride for derivatization. The unprotected skin of hands, face and neck was similarly evaluated for both painting and nonpainting tasks. PPE protected skin areas were also assessed. Samples were extracted in the lab and analyzed on high-pressure liquid chromatography. Hexamethylene diisocyanate (HDI) monomer (ug/inch2) and oligomer (ug/inch2) in monomer equivalent amount were quantified and used for assessment. Results showed that surface levels of HDI (monomer and oligomers; gm+/-gsd) were significantly higher (p<0.001) when HDI-containing hardeners were used (4.28+/-4.22 and 0.16+/-5.99) than when no hardeners were used (0.93+/-1.64 and 0.01+/-1.66). Surfaces with higher contamination were hardener containers (108.06 and 2.90), mixing benches (25.89 and 0.80), rulers (6.33 and 0.50), and gloves (4.67 and 0.11). Average skin exposure was 0.30+/-2.85 (monomer) and 0.006+/-3.13 (oligomer). Levels were significantly higher (p<0.05) for painting tasks (0.51+/-3.98 and 0.01+/-3.97) than non-painting tasks (0.20+/-1.45 and 0.003+/-1.81). Skin exposure under PPE was measured as 0.51+/-2.27 and 0.013+/-2.30 with hardener use, indicating HDI breakthrough. These results suggest surface contamination and skin exposure to isocyanates are common in auto body shops and are affected mainly by painting activities. Skin exposure may significantly contribute to the total isocyanate exposure. In addition, current PPE is inadequate in protecting workers from dermal exposures.
Isocyanates; Exposure-levels; Skin; Skin-exposure; Automotive-industry; Automobile-repair-shops; Personal-protective-equipment; Air-contamination; Airborne-particles; Airborne-dusts; Epidemiology; Statistical-analysis; Painting; Tools; Gloves; Respirators; Monomers; Statistical-analysis; Workers; Work-environment
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American Industrial Hygiene Conference and Exposition, June 2-7, 2001, New Orleans, Louisiana
Page last reviewed: March 25, 2022
Content source: National Institute for Occupational Safety and Health Education and Information Division