Occupational safety standards and warning labels on methylene chloride haven't entirely eliminated fatalities from exposure to this widely used halogenated organic solvent, a new study suggests. Researchers examined data from a wide variety of sources including PubMed and government databases to identify unintentional fatalities associated with methylene chloride from 1980 to 2018. They identified a total of 85 such fatalities, with 74 (87%) occurring in workplaces. "OSHA's methylene chloride regulations can and do protect workers in industrial settings when employers provide the mandated ventilation and protective equipment," said study co-author Dr. Kathleen Fagan, who is retired from the Occupational Safety and Health Administration (OSHA) Office of Occupational Medicine and Nursing in Washington, D.C. "We found that the majority of recent methylene chloride-related deaths in the U.S. occurred in small, unventilated spaces, such as bathrooms," Dr. Fagan said by email. "No regulations can protect people from the extremely high methylene chloride levels in these settings." The most common products involved in occupational fatalities tied to methylene chloride were paint strippers (n=60), researchers report in JAMA Internal Medicine. The proportion of these deaths involving paint strippers increased from 22 (55%) before 2000 to 30 (88%) after 2000. Work in bathrooms also played a larger role in methylene chloride-related fatalities over time, the study found. The proportion of fatalities tied to bathtub or paint stripping in a bathroom climbed from 2 (5%) before 2000 to 21 (62%) after 2000. Nearly all the fatalities in the study involved men (94%) and the median age at death was 31 years for the subset of 70 fatalities with this data available. OSHA investigated 55 (74%) of the fatalities in the study that were identified as occupational deaths. Out of 67 occupational cases with information on the circumstances surrounding exposure to methylene chloride, researchers found that 20 (30%) deaths happened while using equipment such as tanks or pits found uniquely in the workplace. For the 40 (47%) of fatalities with information available on personal protective equipment (PPE), researchers found that a respirator wasn't used in 20 of the 36 occupational cases, and that a supplied respirator approved by NIOSH wasn't used in 16 cases. For 2 of 4 cases outside the workplace with information available on PPE, respirators weren't used in two cases and were inadequate in the other two cases, the study found. One limitation of the study is that fatalities associated with methylene chloride are most likely underestimated due to the fragmented and incomplete system for tracking these deaths, researchers note. Occupational fatalities may also be undercounted because not all workplaces must report to OSHA. While the EPA barred consumer sales of methylene chloride paint strippers in 2019, this rule didn't cover occupational exposure, the study team notes. Prevention of these fatalities, therefore, should focus on replacing products containing methylene chloride with safer alternatives, the study team concludes. "There are multiple alternative products," said Dr. Kenneth Rosenman, chief of the Division of Occupational and Environmental Medicine at Michigan State University in East Lansing who wrote a commentary accompanying the study. In particular, alternative stripper compounds should be used on bathtubs, Dr. Rosenman said by email. "If methylene chloride is used on bathtubs then air supplied respirators - e.g. air hoses - and special gloves should be used - i.e. butyl vinyl or poly vinyl alcohol," Dr. Rosenman added. —Lisa Rapaport Source
