Protecting service and maintenance workers during laboratory chemical hood repairs

Abstract

Laboratory chemical hoods may be the single most important engineering control for protecting laboratory workers from chemical exposures, but their maintenance and repair can present potential health and safety hazards to facilities staff. We performed a comprehensive survey of chemical hood systems in laboratory intensive buildings here at Yale University, including an assessment of air quality in Chemistry Department mechanical rooms where fan systems must be accessed by service and maintenance staff. Air monitoring in these mechanical rooms showed intermittently measurable concentrations of many laboratory chemicals, but their magnitudes when present were very low, ranging from about 10 to more than 6,000 times below their applicable permissible exposure limits. Despite the perception by many facilities staff that chemical exposures are their greatest hazard, we found that traditional physical safety issues are the most prevalent source of risk to those responsible for laboratory hood maintenance.