OSHA addresses emergency response safety in 29 CFR 1910.120, the Hazardous Waste Operations and Emergency Response (HAZWOPER) Standard. Paragraph (q) of this standard specifically covers employees who are involved in emergency response or hazmat emergency operations. It requires that emergency operations be conducted through the use of the Incident Command System (ICS) and that the person in charge of the ICS - the incident commander - assigns an individual as safety official.
This assigned safety official has the authority to override the incident commander's decisions and either alter, suspend or terminate the operations if at any time conditions at the emergency response site are considered immediately dangerous to life and health (IDLH) or pose imminent danger to personnel. The safety official plays a vital role in overseeing everyone's safety and that all operations are carried out in a safe manner.