'Safer' Solvent May Not Be Safe
A "safer" substitute used in place of ozone-depleting chlorofluorocarbons and other regulated compounds may not be safe after all, two CDC publications suggest. The first is a case study published Dec. 5 in Morbidity and Mortality Weekly Report; the second is a Dec. 8 post on the NIOSH Science blog by G. Scott Dotson, Ph.D., an industrial hygienist in the NIOSH Education and Information Division, and Charles L. Geraci, Ph.D., CIH, a supervisory physical scientist and chief of the Document Development Branch in the same division.
Dotson and Geraci note use of 1-BP in manufacturing has been rising, and it is used in some states as an alternative solvent in the dry cleaning industry in response to restrictions on perchloroethylene, which is considered "probably carcinogenic to humans" by the International Agency for Research on Cancer.
"The toxic nature of 1-BP is not fully understood. Case reports demonstrating neurotoxic, reproductive, development and other health effects in workers who use or make 1-BP indicate that the brominated solvent may represent an unrecognized occupational health risk," the two men wrote.
The MMWR case study explores two independent cases of 1-BP-exposed electronics and dry cleaning workers diagnosed with the clinical manifestations of neurotoxicity. The cases were reported to regional poison control centers in Pennsylvania (2007) and New Jersey (2008) by attending physicians who treated the affected workers. Both cases were investigated by federal and state health agencies; the New Jersey case is now being investigated further by the New Jersey Department of Health and Senior Services and CDC, according to MMWR.
"These cases . . . when coupled with previously reported studies of workers exposed to 1-BP in the foam cushion manufacturing industry, illustrate the potential health risk of 1-BP exposures," Dotson and Geraci write. They report that the National Toxicology Program has concluded 1-BP causes developmental and reproductive toxicity among animals exposed to it, and NIOSH is in the process of evaluating exposures and potential health effects among workers potentially exposed to it. "Additionally, NIOSH is working with a major manufacturer of 1-BP products to better understand their extent of use, proper methods for handling the material, and practices that will minimize worker exposure," they write. NIOSH and OSHA do not have recommended or mandatory exposure limits set for 1-BP, but the American Conference of Governmental Industrial Hygienists recommends an 8-hour time weighted average of 10 parts per million, and other professional organizations and manufacturers have recommended exposure limits ranging from 20 to 100 ppm, according to the post.