In 2010, researches cognitively tested 2,143 retired French utility workers. The researchers determined the workers’ lifetime exposure to chlorinated solvents, petroleum solvents, and benzene using a job exposure matrix. Thirty-three percent of the workers were exposed to chlorinated solvents, twenty-six percent to benzene, and twenty-five percent to petroleum solvents. The study found high exposure to solvents was significantly associated with reduced cognitive abilities. The greatest risk was associated with workers with high, recent exposure to solvent vapors, including groups of workers not normally associated with solvent exposure. The risk of cognitive impairments declined slightly over time, but still presented an elevated risk to the retirees. The researchers believe that workers with moderate exposure may have reduced risk of cognitive impairments over time, but this risk-reduction may not occur for workers with high exposure levels. Workers with high exposure levels still suffered from elevated cognitive risks even when their last exposure to solvents in the workplace occurred fifty years ago.
Employers that are able to reduce or replace their use of solvents may decide that it is beneficial to do so. Employers may also decide to use additional engineering controls and practices or personal protective equipment to further reduce employee exposure levels. Erika Sabbath, the lead author of the study, said that, in addition to protecting workers’ health, reduced exposure to solvents “could benefit organizations, payers, and society by reducing workers’ post-retirement health care costs and enabling them to work longer.”
The Occupational Safety and Health Administration (OSHA) sets exposure limits for many solvents, but these limits are often decades-old and do not reflect current research. OSHA recently released informational permissible exposure limit tables that reflect more recent research. These tables are not binding as they have not gone through the official rulemaking process. It is possible, however, that OSHA could use the informational tables as evidence of general industry standards and practices when it alleges a company violated the General Duty Clause of the Occupational Safety and Health Act. Studies, such as this one, may convince OSHA to modernize its permissible exposure limits.
Erika L. Sabbath, ScD, Laure-Anne Gutierrez, MS, Cassandra A. Okechukwu, ScD, Archana Singh-Manoux, PhD, Hélène Amieva, PhD, Marcel Goldberg, MD, PhD, Marie Zins, MD, Phd, and Claudine Berr, MD, PhdD, Time may not fully attenuate solvent-associated cognitive deficits in highly exposed workers, Neurology, May 13, 2014
Josh Cable, Study: Exposure to Solvent Vapors Can Impair Cognitive Ability Long After Retirement, EHS Today, May 13, 2014
OSHA, Permissible Exposure Limits – Annotated Tables, https://www.osha.gov/dsg/annotated-pels/
Jason Loh, Red-on-line EHS Legal Counsel