A Summary of

Employer Responsibilities Under

The Hazard Communication Standard




Compiled By:

Tony Rieck

T.R. Consulting, Inc.


March 2002





The HCS requires employers to establish hazard communication programs to transmit information on the hazards of chemicals to their employees by means of labels on containers, material safety data sheets, and training programs. Implementation of these hazard communication programs will ensure all employees have the "right-to-know" the hazards and identities of the chemicals they work with, and will reduce the incidence of occupational illnesses and injuries related to chemical exposures.


In March of 1994, clarification of several aspects of the rule that had proved confusing was provided, including a number of minor changes and technical amendments.   In particular, the rule added and clarified certain exemptions from labeling and other requirements; modified and clarified aspects of the written hazard communication program and labeling requirements; clarified and slightly modified the duties of distributors, manufacturers, and importers to provide material safety data sheets (MSDSs) to employees; and clarified certain provisions regarding MSDSs.





The purpose of the HCS is to provide workers with the right to know the hazards and identities of the chemicals they are exposed to while working, as well as the measures they can take to protect themselves. It was estimated at the time of rule making that there were over 32 million workers exposed to hazardous chemicals in over 3.5 million workplaces.  According to the National Institute for Occupational Safety and Health (NIOSH), there were as many as 575,000 hazardous chemical products in these workplaces at the time that the HCS was proposed for amendment. Based on the growth rate of the chemical industry with regard to new products, this number was estimated to grow to as many as 650,000 chemical products by the implementation date for these regulations in March of 1994. Chemical exposures occur in every type of industry. In fact, workers typically experience multiple exposures to numerous industrial chemicals at one point of time or over a long period of employment.


Besides having what OSHA considered an inherent right to know about hazardous chemicals in their workplaces, exposed employees have a need to know this information as they are at significant risk of experiencing adverse health or physical effects in the absence of such knowledge. Chemicals pose a myriad of hazards to exposed workers, from mild health effects, such as irritation, to death. Some chemicals cause or contribute to chronic diseases, such as heart disease, kidney disease, sterility, or cancer. Many chemicals cause acute injuries or illnesses such as rashes, burns, and poisoning. Numerous chemicals pose physical hazards to workers by contributing to accidents like fires and explosions.


The HCS achieves its purpose by an integrated three - pronged system. First, chemical manufacturers and importers must review available scientific evidence concerning the physical and health hazards of the chemicals they produce or import to determine if they are hazardous. Second, for every chemical found to be hazardous, the chemical manufacturer or importer must develop comprehensive material safety data sheets (MSDSs) and warning labels for containers and send both downstream along with the chemicals. Third, all employers must develop a written hazard communication program and provide information and training to employees about the hazardous chemicals in their workplace.


The three information components in this system - labels, material safety data sheets, and worker training - are all essential to the effective functioning of the program. The MSDSs provide comprehensive technical information, and serve as a reference document for exposed workers as well as health professionals providing services to those workers. The labels provide a brief synopsis of the hazards of the chemicals at the site where the chemical is used in the work area. Training ensures that workers understand the information on both MSDSs and labels, know how to access this information when needed, and are aware of the proper protective procedures to follow.


The original rule, which was promulgated on November 25, 1983, covered employees in the manufacturing sector of industry. That rule was modified on August 24, 1987 to expand the coverage to all industries where employees are exposed to hazardous chemicals. Complete implementation of the standard's requirements in the non-manufacturing sector was subsequently delayed by various court and administrative actions. However, the August 24, 1987, rule is now fully effective and has been so since January 24, 1989, and is being enforced in all industries.





Under the HCS, the manufacturer, importer, or distributor is required to label each container of hazardous chemicals. If the hazardous chemicals are transferred into unmarked containers, these containers must be labeled with the required information, unless the container into which the chemical is transferred is intended for the immediate use of the employee who performed the transfer.


Hazard information must be transmitted on Material Safety Data Sheets (MSDSs) that must be distributed to the customer at the time of first shipment of the product. The Hazard Communication Standard also requires that MSDSs be updated by the chemical manufacturer or importer within three months of learning of "new or significant information" regarding the chemical's hazard potential.


OSHA does not require that MSDSs be provided to purchasers of household consumer products when the products are used in the workplace in the same manner that a consumer would use them, i.e.; where the duration and frequency of use (and therefore exposure) is not greater than what the typical consumer would experience. This exemption in OSHA's regulation is based, however, not upon the chemical manufacturer's intended use of his product, but upon how it actually is used in the workplace.  (An employee whose job is to clean tile using a product intended for cleaning tile would most certainly be exposed for longer durations and more frequently than a person cleaning their personal shower tile once each week).  Employees who are required to work with hazardous chemicals in a manner that results in a duration and frequency of exposure greater than what a normal consumer would experience have a right to know about the properties of those hazardous chemicals.  Examples of household chemical applications that would require obtaining and maintaining MSDSs would include:  use of the chemical by employees in a confined area, exposure to greater amounts of a chemical than a household exposure (i.e. Acetone is purchased in small containers for use in removing fingernail polish and exposure would be limited to a few hours each week.  In the work place, purchased containers of acetone are typically of significantly greater size and employee exposure is more frequent or for longer periods of time than those typically experienced by individuals exposed removing fingernail polish in their homes) and purchases of chemicals in quantities exceeding those associated with consumer use.


MSDSs that represent non-hazardous chemicals are not covered by the HCS. The standard requires that "the employer shall maintain in the workplace copies of the required MSDSs for each hazardous chemical, and shall ensure that they are readily accessible during each work shift to employees when they are in their work area(s)." OSHA does not require nor encourage employers to maintain MSDSs for non-hazardous chemicals. Consequently, an employer is free to discard MSDSs for non-hazardous chemicals.




Employees are to be trained at the time they are assigned to work with a hazardous chemical. The intent of this provision is to have information presented to employees prior to exposure to prevent the occurrence of adverse health effects. This purpose cannot be met if training is delayed until a later date.

The training provisions of the HCS are not satisfied solely by giving an employee the data sheets to read. An employer's training program is to be a forum for explaining to employees not only the hazards of the chemicals in their work area, but also how to use the information generated in the hazard communication program. This can be accomplished in many ways (audiovisuals, classroom instruction, interactive video), and should include an opportunity for employees to ask questions to ensure that they understand the information presented to them.

Training need not be conducted on each specific chemical found in the workplace, but may be conducted by categories of hazard (e.g., carcinogens, sensitizers, acutely toxic agents) that are or may be encountered by an employee during the course of his duties.

Also, the training must be comprehensible. If the employees receive job instructions in a language other than English, then the training and information to be conveyed under the HCS will also need to be conducted in a foreign language.


Additional training is to be done whenever a new physical or health hazard is introduced into the work area, not a new chemical. For example, if a new solvent is brought into the workplace, and it has hazards similar to existing chemicals for which training has already been conducted, then no new training is required. As with initial training, and in keeping with the intent of the standard, the employer must make employees specifically aware which hazard category (i.e., corrosive, irritant, etc.) the solvent falls within. The substance-specific data sheet must still be available, and the product must be properly labeled. If the newly introduced solvent is a suspect carcinogen, and there has never been a carcinogenic hazard in the workplace before, then new training for carcinogenic hazards must be conducted for employees in those work areas where employees will be exposed.

It is not necessary that the employer retrain each new hire if that employee has received prior training by a past employer, an employee union, or any other entity. General information, such as the rudiments of the HCS could be expected to remain with an employee from one position to another. The employer, however, maintains the responsibility to ensure that their employees are adequately trained and are equipped with the knowledge and information necessary to conduct their jobs safely. It is likely that additional training will be needed since employees must know the specifics of their new employers' programs such as where the MSDSs are located, details of the employer's in-plant labeling system, and the hazards of new chemicals to which they will be exposed. For example, it is required that employees be trained on the measures they can take to protect themselves from hazards, including specific procedures the employer has implemented such as work practices, emergency procedures, and personal protective equipment to be used. An employer, therefore, has a responsibility to evaluate an employee's level of knowledge with regard to the hazards in the workplace, their familiarity with the requirements of the standard, and the employer's hazard communication program.


The HCS can be found at 29 CFR Part 1910.1200.