Comprehensibility of material safety data sheets.

The Hazard Communications Standard, commonly known as the Worker Right to Know law, requires that a chemical information sheet, known as a material safety data sheet (MSDS), be produced for all hazardous chemicals. This study examines the comprehensibility of a sample of MSDSs to a group of about 100 unionized workers in manufacturing industries located in the state of Maryland. Workers were given several MSDSs and performed the equivalent of an open-book test answering questions regarding health and safety information that was provided on the MSDS. On average, the information on the MSDSs was found to be about one-third incomprehensible. This result raises concerns regarding policies and practices for hazard communication. There is a clear indication that MSDSs need to be improved if workers must rely on them for health and safety information.