| Title: | Hexavalent chromium and isocyanate exposures during military aircraft painting under crossflow ventilation |
| Author(s): | Bennett JS; Marlow DA; Nourian F; Breay J; Hammond D; |
| Address: | "a National Institute for Occupational Health, Division of Applied Research Technology , Cincinnati Ohio. b U.S. Navy Medical Center San Diego , Industrial Hygiene Department , San Diego California" |
| DOI: | 10.1080/15459624.2015.1117617 |
| ISSN/ISBN: | 1545-9632 (Electronic) 1545-9624 (Print) 1545-9624 (Linking) |
| Abstract: | "Exposure control systems performance was investigated in an aircraft painting hangar. The ability of the ventilation system and respiratory protection program to limit worker exposures was examined through air sampling during painting of F/A-18C/D strike fighter aircraft, in four field surveys. Air velocities were measured across the supply filter, exhaust filter, and hangar midplane under crossflow ventilation. Air sampling conducted during painting process phases (wipe-down, primer spraying, and topcoat spraying) encompassed volatile organic compounds, total particulate matter, Cr[VI], metals, nitroethane, and hexamethylene diisocyanate, for two worker groups: sprayers and sprayer helpers ('hosemen'). One of six methyl ethyl ketone and two of six methyl isobutyl ketone samples exceeded the short term exposure limits of 300 and 75 ppm, with means 57 ppm and 63 ppm, respectively. All 12 Cr[VI] 8-hr time-weighted averages exceeded the recommended exposure limit of 1 microg/m3, 11 out of 12 exceeded the permissible exposure limit of 5 microg/m3, and 7 out of 12 exceeded the threshold limit value of 10 microg/m3, with means 38 microg/m3 for sprayers and 8.3 microg/m3 for hosemen. Hexamethylene diisocyanate means were 5.95 microg/m3 for sprayers and 0.645 microg/m3 for hosemen. Total reactive isocyanate group--the total of monomer and oligomer as NCO group mass--showed 6 of 15 personal samples exceeded the United Kingdom Health and Safety Executive workplace exposure limit of 20 microg/m3, with means 50.9 microg/m3 for sprayers and 7.29 microg/m3 for hosemen. Several exposure limits were exceeded, reinforcing continued use of personal protective equipment. The supply rate, 94.4 m3/s (200,000 cfm), produced a velocity of 8.58 m/s (157 fpm) at the supply filter, while the exhaust rate, 68.7 m3/s (146,000 cfm), drew 1.34 m/s (264 fpm) at the exhaust filter. Midway between supply and exhaust locations, the velocity was 0.528 m/s (104 fpm). Supply rate exceeding exhaust rate created re-circulations, turbulence, and fugitive emissions, while wasting energy. Smoke releases showing more effective ventilation here than in other aircraft painting facilities carries technical feasibility relevance" |
| Keywords: | "Air Pollutants, Occupational/*analysis *Aircraft Butanones/analysis California Chromium/*analysis Ethane/analogs & derivatives/analysis Isocyanates/*analysis Metals/analysis Methyl n-Butyl Ketone/analysis Military Personnel Nitroparaffins/analysis Occupat;" |
| Notes: | "MedlineBennett, James S Marlow, David A Nourian, Fariba Breay, James Hammond, Duane eng CC999999/Intramural CDC HHS/ England 2015/12/25 J Occup Environ Hyg. 2016; 13(5):356-71. doi: 10.1080/15459624.2015.1117617" |
