The Hazard Communication Standard (HCS) (29 CFR 1910.1200(g)), revised in 2012, requires that the chemical manufacturer, distributor, or importer provide Safety Data Sheets (SDSs) (formerly MSDSs or Material Safety Data Sheets) for each hazardous chemical to downstream users to communicate information on these hazards. The information contained in the SDS is largely the same as the MSDS, except now the SDSs are required to be presented in a consistent user-friendly, 16-section format. This brief provides guidance to help workers who handle hazardous chemicals to become familiar with the format and understand the contents of the SDSs. It is an important component of product stewardship and occupational safety and health. It is intended to provide workers and emergency personnel with procedures for handling or working with substances in a sage manner and should include information such as physical data (melting point, boiling point, flash point, etc), toxicity, health effects, first aid, reactivity, storage, disposal, protective equipment and spill handling procedures. SDS formats can vary from source to source within a country depending on national requirements. SDSs typically contain a section for product ingredients; however, this information is often incomplete.