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An approach for estimating workplace exposure to o-toluidine, aniline, and nitrobenzene.

Pendergrass SM
Am Ind Hyg Assoc J 1994 Aug; 55(8):733-737
A method was developed for estimating workplace exposure to o- toluidine (95534), aniline (62533), and nitrobenzene (98953). In order that the method be comprehensive, a combination of new and established sample collection and analytical techniques was used. Surface wipes and passive dermal badges were used as indicators of dermal exposure. In the case of airborne exposures, sulfuric-acid impregnated filters in various sizes of silica-gel tubes, as well as the latter alone were employed as quantitative indicators. Sample desorption efficiency studies were determined at levels about one half the NIOSH recommended exposure limit in various desorption solvents. Recovery of all three analytes indicated that ethanol was the best desorption solvent. Surface wipes provided acceptable quantitative estimates of potential o-toluidine and aniline exposures, with mean recoveries averaging 92%. Only 14% of the nitrobenzene was recovered after an 8 hour (hr) exposure. The best recovery of o-toluidine and aniline were with the dermal badge samplers (more than 95% and 88%, respectively). Nitrobenzene was recovered at very acceptable levels after 24hr (more than 92%). Air monitoring with silica-gel tubes showed that o-toluidine and aniline were most effectively collected on loadings of 150/75 milligrams per tube (mg/t) at relative humidities of about 53%. Nitrobenzene was more effectively collected when silica-gel loadings were 520/260mg/t. A storage stability test indicated that nitrobenzene was more than 87% stable after 21 days, whereas recoveries of o- toluidine and aniline after only 8 days were 76% and 64%, respectively. These were reduced to 59% and 50%, respectively, after 14 days. Both these chemicals were successfully collected on Gelman acid treated filters. Nitrobenzene passed through Gelman tubes unaffected, and was successfully recovered at low humidity, but collection efficiency was reduced at high humidity. It was effectively recovered from the large silica-gel tubes after storage for 60 days (95% recovery). The authors conclude that the combined method provides a comprehensive means for monitoring dermal and airborne exposures to the three chemicals.
NIOSH-Author; Air-monitoring; Air-samplers; Carcinogens; Comparative-toxicology; Environmental-pollution; Filter-membranes; Occupational-exposure; Pollutants
95-53-4; 62-53-3; 98-95-3
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Journal Article
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NIOSH Division
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American Industrial Hygiene Association Journal
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division