If a chemical is a physical hazard, then there is scientifically valid evidence that it is a combustible liquid, a compressed gas, explosive, flammable, an organic peroxide, an oxidizer, pyrophoric, unstable (reactive), or water-reactive. These chemicals are capable of physically damaging tissues through heat, pressure, or chemical reaction.

Chemicals that pose health hazards may cause either acute or chronic effects on the health of exposed employees. These chemicals include carcinogens, toxic or highly toxic agents, reproductive toxins (mutagens and teratogens), irritants, corrosives, sensitizers, hepatotoxins, nephrotoxins, neurotoxins, agents which act on the hematopoietic system, and agents which damage the lungs, skin, eyes, or mucous membranes. A single study conducted in accordance with established scientific principals which provides statistically significant evidence for health effects is enough to warrant classifying a chemical as a health hazard.

It is the responsibility of the chemical manufacturer (or importer) to conduct the required scientific testing to determine if a chemical poses a physical or health hazard. The end user is not required to make this determination.

OSHA has also established criteria for hazardous chemicals in mixtures. Products which contain a hazardous chemical at a concentration greater than one percent (by weight or volume) are regulated as hazardous chemicals, unless testing of the mixture as a whole has shown that it is not a physical or health hazard. If a constituent chemical is classified as a carcinogen, and is present at a concentration greater than 0.1%, then the mixture is assumed to present a carcinogenic hazard.

There are a number of important exemptions from the hazard communication standards promulgated by OSHA. These exemptions are listed in 29 CFR 1910.1200(a)(6), and include: hazardous wastes, tobacco products, wood products, most foods and drinks, medicines and cosmetics, consumer products used in a duration and frequency of exposure not greater than what consumers experience when using the product. Additionally, articles, manufactured items (not fluid or particle) formed to a specific shape or design during manufacture (where the shape or design is integral to their use), and which do not release more than trace amounts of hazardous chemicals during normal use are exempt from 29 CFR 1910.1200 requirements. If installation personnel are uncertain about the applicability of the standard to a particular product, they should contact Bioenvironmental Engineering.

The OSHA Hazard Communication Standard
Installations are required by 29 CFR 1910.1200 (e) to develop, implement and maintain a written hazard communication program. The program requires the installation to maintain a list of hazardous chemicals present in the workplace. In addition, it describes how labels and other forms of warning are maintained, how and where material safety data sheets (MSDSs) are kept, and how employee training and information requirements will be met. The written hazard communication program also must describe methods used to inform employees about the hazards of non-routine tasks and the hazards associated with unlabeled pipes in their work areas. Specific labeling, MSDS, and training requirements are discussed below.

Labeling Requirements
Chemical manufacturers are required by 29 CFR 1910.1200 (f) to ensure each container of hazardous chemicals shipped is labeled, tagged, or marked with critical hazard information. This information includes the identity of the hazardous chemical(s) in the product, the appropriate hazard warnings (e.g., irritant, flammable, etc.), and the name and address of the chemical manufacturer. This labeling provides the installation with the information needed to comply with the workplace labeling requirements in 29 CFR 1910.1200 (f) (5-9). Installations must ensure that each container is labeled, tagged, or marked with the identity of the hazardous chemical(s) in the product and appropriate hazard warnings in words, pictures, symbols or some combination that gives at least general information on the chemical's hazards. Alternatively, the installation importer or other responsible party may use signs, placards, process sheets, batch tickets, written operating procedures, or other written materials to inform employees of chemical hazards, so long as the containers to which the warnings apply are clearly identified. The labels or other written materials must be clearly legible, in English (translations into other languages may be added to the English text), and prominently displayed or readily accessible to employees throughout the work shift. Portable containers used to transfer hazardous chemicals that will immediately be used by the employees performing the transfer need not be labeled.

Material Safety Data Sheet (MSDS) Requirements
The purpose of a MSDS is to inform employees of the hazards and routes of exposure associated with the chemicals they work with, to describe precautions for safe handling, to provide information on measures that should be taken in an emergency (such as a spill or fire) and to provide medical personnel with information needed to treat employees who suffer from overexposures to the chemicals. MSDSs are frequently organized into specific sections that include the information required by 29 CFR 1910.1200 (g).

The preparation of MSDSs is the responsibility of the chemical manufacturer or importer. According to 29 CFR 1910.1200 (g) (6), chemical manufacturers must provide the MSDS with the first shipment of the hazardous chemical, and with the first shipment made after the MSDS is revised. The chemical manufacturer must also provide the MSDS upon request. It is the responsibility of the installation to request a MSDS if one is not provided with the initial shipment. If the installation has lost an MSDS, or has illegible copies, a new MSDS must be requested from the manufacturer or distributor.

Installations must maintain copies of MSDSs for each hazardous chemical in the workplace, and must ensure that they are readily accessible to employees when they are in their work areas. It is not sufficient to have a central collection of MSDSs where employees must leave their work area to view them. Paper copies of the MSDS are not required if electronic access, microfiche or another alternative format exists and does not create any barriers to employee access in each work area. If employees must travel between work areas during a shift, MSDSs need only be kept in the primary work area, provided that there is immediate access to them in an emergency. It is permissible to change the form of a MSDS to include them in operating procedures or manuals, and they may be designed to cover groups of hazardous chemicals where it may be more appropriate to address the hazards of a process. Again, the information must be complete and readily accessible. MSDSs must be provided upon request to OSHA inspectors.

Employee Information and Training Requirements
Employees must be given effective information and training at the time of their initial assignment to a work area where hazardous chemicals are used, and whenever a new hazard is introduced for which they have not received prior training. The information and training may be designed to cover types of physical and health hazards; however, chemical-specific information must always be available through labels and MSDSs.

Installations must inform each employee of the training requirements of 29 CFR 1910.1200 (h); any operations in their work area involving hazardous chemicals; and the location and availability of the written hazard communication program, the list of hazardous chemicals, and the required MSDSs.