2-MeO-4-NA, (a dye component), was nominated in 2006 by the National Cancer Institute for toxicology and carcinogenesis studies under the National Toxicology Program (NTP). The nomination was based on the high and increasing national aggregated annual production volume (500K ? 1 million pounds based on the U.S. EPA's 2006 Inventory Update Rule), the potential for worker exposures, the lack of adequate toxicology and carcinogenicity data, positive mutagenicity data, and the determination that a closely related chemical, 2-methoxy-5-nitroaniline, was a multisite carcinogen when tested by the NTP. There are limited environmental and occupational exposure data available in the scientific literature to assess the acute exposure/response relationship, and potential chronic long-term adverse effects of 2-MeO-4-NA exposure. Also, there are no formally documented sampling and analytical methods to quantitatively measure airborne and surface exposures. There are no Occupational Safety and Health Administration (OSHA) regulations specific to limiting occupational exposures to 2-MeO-4-NA. NIOSH has not established a time-weighted average Recommended Exposure Level (REL), and the American Conference of Governmental Industrial Hygienists (ACGIH) has not established a time-weighted average Threshold Limit Value (TLV(R)) for 2-MeO-4-NA. Therefore, NIOSH has evaluated workplace inhalation and surface exposures to 2-MeO-4-NA in a commercial manufacturing setting. These studies include worker exposure surveys at facilities that produce raw 2-MeO-4-NA, and facilities that use 2-MeO-4-NA for the manufacture of end use products. An analytical method for 2-MeO-4-NA has been completed. The manufacturing/ industrial usage profile of 2-MeO-4-NA to characterize industry wide occupational exposures including total number of workers and evaluate patterns of exposure has also been completed. Industrial hygiene sampling surveys (that collect air and wipe samples) are planned at two 2-MeO-4-NA users with completion expected by the end of FY10. A complete industrial hygiene survey report that details range of exposures and suggested countermeasures for the above sites will be prepared once data collection has ended.
