Most industries use hazardous chemicals to some degree. Because hazardous chemicals are regulated by so many different entities for different aspects of their life-cycle (manufacturing, transportation, storage, handling, use, and disposal), it can be difficult for a site to capture all of the EHS-related requirements in a single program; and therefore difficult to effectively audit compliance with all of those requirements.
Transportation requirements are addressed almost entirely by DOT regulations. Disposal regulations are addressed by EPA regulations. But while most people look to OSHA regulations for the requirements for storage, handling, labeling and use, there are other regulations that come into play. Many of the things that we all have a general sense of - for instance, that incompatible chemicals should be stored so that they don't accidentally mix together in case the containers leak or that combustible materials shouldn't be stored on top of a flammables storage cabinet - are not found anywhere in OSHA regulations. But they can be found in Fire Code standards.
There are two major Fire Codes used in the US: the International Fire Code (IFC), published by the International Code Council; and NFPA 1 - Fire Code, published by the National Fire Protection Association. Both of these are consensus standards that are written and adopted by committees of fire safety experts and interested participants. Each standard is updated every three years. With a few exceptions, some version of these codes has been adopted throughout the US, and therefore has the force of law either on a statewide basis or on a local level. It is not uncommon for an older edition of a Code to continue to be enforced in a particular jurisdiction, even after updates have been published.