The Occupational Health and Safety Administration’s Hazard Communication Standard, 29 C.F.R. § 1910.1200, and many state and local Right-to-Know regulations require the marking of hazardous materials storage vessels, piping, and process units within industry. Although the format may vary, the markings should clearly spell out the hazard class or specific contents of the container.

Fire codes established by state and local jurisdictions often mandate the use of the NFPA 704 marking system, which also includes tank and storage areas.

Industry uses several hazard communication marking systems: an example is the Hazardous Materials Information System. This system provides a standardized hazard rating scale from 0 (i.e., minimal hazard) to 4 (i.e., extreme hazard) for health, flammability, and reactivity similar to NFPA 704.