Bennett James S, Marlow David A, Nourian Fariba, Breay James, Hammond Duane
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.
J Occup Environ Hyg. 2016;13(5):356-71. doi: 10.1080/15459624.2015.1117617.
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 µg/m3, 11 out of 12 exceeded the permissible exposure limit of 5 µg/m3, and 7 out of 12 exceeded the threshold limit value of 10 µg/m3, with means 38 µg/m3 for sprayers and 8.3 µg/m3 for hosemen. Hexamethylene diisocyanate means were 5.95 µg/m3 for sprayers and 0.645 µg/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 µg/m3, with means 50.9 µg/m3 for sprayers and 7.29 µg/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.
在一个飞机喷漆机库中对暴露控制系统的性能进行了调查。通过在F/A - 18C/D攻击战斗机喷漆期间进行的四次现场空气采样,检查了通风系统和呼吸保护计划限制工人接触的能力。在错流通风条件下,测量了送风过滤器、排风过滤器和机库中平面的风速。在喷漆过程阶段(擦拭、底漆喷涂和面漆喷涂)进行的空气采样涵盖了挥发性有机化合物、总颗粒物、六价铬、金属、硝基乙烷和六亚甲基二异氰酸酯,涉及两个工人群体:喷漆工和喷漆助手(“送管工”)。六个甲乙酮样本中的一个和六个甲基异丁基酮样本中的两个超过了300 ppm和75 ppm的短期接触限值,平均值分别为57 ppm和63 ppm。所有12个六价铬8小时时间加权平均值均超过了1 μg/m³的推荐接触限值,12个中有11个超过了5 μg/m³的允许接触限值,12个中有7个超过了10 μg/m³的阈限值,喷漆工的平均值为38 μg/m³,送管工的平均值为8.3 μg/m³。六亚甲基二异氰酸酯的平均值喷漆工为5.95 μg/m³,送管工为0.645 μg/m³。总反应性异氰酸酯基团——单体和低聚物作为NCO基团质量的总和——显示15个个人样本中有6个超过了英国健康与安全执行局20 μg/m³的工作场所接触限值,喷漆工的平均值为50.9 μg/m³,送管工的平均值为7.29 μg/m³。超过了几个接触限值,这进一步证明了继续使用个人防护设备的必要性。送风速率为94.4 m³/s(200,000立方英尺每分钟),在送风过滤器处产生的风速为8.58 m/s(157英尺每分钟),而排风速率为68.7 m³/s(146,000立方英尺每分钟),在排风过滤器处吸入的风速为1.34 m/s(264英尺每分钟)。在送风和排风位置之间的中途,风速为0.528 m/s(104英尺每分钟)。送风速率超过排风速率会产生再循环、湍流和逸散排放,同时还会浪费能源。烟雾释放表明此处的通风比其他飞机喷漆设施更有效,具有技术可行性意义。