A Practice Note describing the authority and rulemaking process of the Occupational Safety and Health Administration (OSHA) for implementing workplace health and safety regulations, including permanent standards and emergency temporary standards (ETS). It addresses employer notice, compliance, and participation in the rulemaking process, including submitting comments, requesting variances, and seeking judicial review of a standard. This Note also describes how states with OSHA-approved plans adopt standards that are at least as effective as new federal standards, as well as independent state-initiated rules.