An exposure assessment of a laboratory assistant to hazardous chemical substances

Abstract

A survey was conducted to measure exposure to hazardous chemical substances of a laboratory assistant working in a university laboratory, who complained of symptoms that could be indicative of chemical absorption. This case study describes the survey to quantify the exposure in order to determine whether it exceeded safety limits and recommend preventative measures if indicated. Exposure was sampled using a direct reading photo-ionization detector and coconut charcoal sorbent tubes. An additive effect between the different hazardous chemicals was identifi ed. The 8-hour TWA exposure to acetone and dichloromethane was well below the occupational exposure limits, but was more than double the OEL-RL for chloroform. It was also likely that the OEL-STEL for dichloromethane (methylene chloride) was exceeded. Immediate removal for medical assessment and improved preventative measures were recommended.