OSHA issues draft guidance for ‘weight of evidence’ approach

Washington – A new draft OSHA document outlines how employers can use an approach known as “weight of evidence” to assist in classifying hazardous chemicals.

The process is intended to help employers evaluate scientific studies on chemical hazards, which can in turn be used to determine what information needs to be included on chemical labels and Safety Data Sheets, as required under the Hazard Communication Standard.

The draft provides guidance on how employers can use the weight-of-evidence approach in a way that is consistent with criteria in the United Nations’ Globally Harmonized System of Classification and Labeling of Chemicals, which served as the basis for OSHA’s recent update to its hazcom rule. The document outlines for employers what information needs to be considered when classifying health hazards, how to evaluate the evidence in classification, the scope of weight of evidence, and considerations when using weight of evidence.

“This guidance will help educate chemical manufacturers and importers about OSHA’s expectations on how to prepare accurate Safety Data Sheets and labels required to protect worker safety and health,” OSHA administrator David Michaels said in a press release.

Comments on the draft are due March 31.