The Hazard Communication Standard (HCS) requires employers to disclose toxic and hazardous substances in workplaces. This is related to the Worker Protection Standard.

Specifically, this requires unrestricted employee access to the Material Safety Data Sheet (MSDS), Globally Harmonized System of Classification and Labeling of Chemicals (GHS) or equivalent, and appropriate training to understand health and safety risks. This requirement was made necessary to ensure that the employees/workers understand the possibility of risk of chemicals and the measure/method to treat each hazard while staying safe. In addition, the chemical and any mixture's classification are also needed.  

Before the GHS, the MSDS was primarily used in the United States, and it was often translated differently in other countries. Increased international trade created conflict and confusion between different methods of classifications and labeling of the same chemical from one country to the next. Therefore, the GHS was created to aid in a universal process of classifying and labeling all substances. Given that no sheet is ever completely perfect, the GHS is updated about every two years. The ninth revision is the most current, released in December 2021. 

European Union (EU) began to adopt the GHS into their standards in 2009, having the EU Classification, Labelling and Packaging (CLP) reflect the same as the GHS before putting it into full force. Following was the United States, which finally adopted the GHS in 2012, and it is now known as OSHA's HCS 2012 when referenced for enforcement. Canada adopted the GHS in 2015, changing the federal Hazardous Product Act (HPA) and making a new regulation. The Hazardous Products Regulations (HPR) were created under the HPA to embody the GHS as the new standard. 

As the world continues to trade and understand more of the effects of chemicals, the HCS will change—however, currently the GHS has made communication regarding hazards much more straightforward and is well adopted. Therefore, GHS is expected be part of the HCS in the future as a common standard used to provide the same chemical information to the end user.

History

Workplace safety in the USA began long before Dr. Alice Hamilton in Chicago, who began working for the state of Illinois in 1910 to deal with workplace safety.

The Occupational Safety and Health Administration was established in 1970 to standardize safety for nearly all workers in the United States, and hazard communication for toxic substance exposure was included during the 1980s.

The Globally Harmonized System of Classification and Labeling of Chemicals (GHS) is currently being pursued to standardize workplace hazard protection internationally. As GHS has been adopted as the Hazard Communication Standard in the following Countries with the year of adoption. 

* The countries covered by the EU/ European Economic Area (EEA): Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Netherlands and the United Kingdom.

OSHA's Hazard Communication Standard (HAZCOM) was first adopted in 1983 in the United States with limited scope (48 FR 53280; November 25, 1983). In 1987, scope was expanded to cover all industries where employees are potentially exposed to hazardous chemicals (52 FR 31852; August 24, 1987). This is managed by the Occupational Safety and Health Administration. This is managed by states that have an approved plan.

The standard is identified in 29 C.F.R. 1910.1200. The summary is as follows.

"This occupational safety and health standard is intended to address comprehensively the issue of classifying the potential hazards of chemicals, and communicating information concerning hazards and appropriate protective measures to employees, and to preempt any legislative or regulatory enactments of a state, or political subdivision of a state, pertaining to this subject. Classifying the potential hazards of chemicals and communicating information concerning hazards and appropriate protective measures to employees, may include, for example, but is not limited to, provisions for: developing and maintaining a written hazard communication program for the workplace, including lists of hazardous chemicals present; labeling of containers of chemicals in the workplace, as well as of containers of chemicals being shipped to other workplaces; preparation and distribution of safety data sheets to employees and downstream employers; and development and implementation of employee training programs regarding hazards of chemicals and protective measures. Under section 18 of the Act, no state or political subdivision of a state may adopt or enforce any requirement relating to the issue addressed by this Federal standard, except pursuant to a Federally-approved state plan."

The United States Department of Defense does not manage hazards in accordance with public law.
 DoD and the right to know

Purpose

The Purpose is identified in 29 C.F.R. 1910 1200, and is defined as follows: 

"The purpose of this section is to ensure that the hazards of all chemicals produced or imported are classified, and that information concerning the classified hazards is transmitted to employers and employees. The requirements of this section are intended to be consistent with the provisions of the United Nations Globally Harmonized System of Classification and Labelling of Chemicals (GHS), Revision 3. The transmittal of information is to be accomplished by means of comprehensive hazard communication programs, which are to include container labeling and other forms of warning, safety data sheets and employee training."

Employees access to hazard information is one of the prerequisites required for access to competent medical diagnosis and treatment.

Environmental illness share characteristics with common diseases. Cyanide exposure symptoms include weakness, headache, nausea, confusion, dizziness, seizures, cardiac arrest, and unconsciousness. Influenza and heart disease include the same symptoms. Failure to obtain proper disclosure is likely to lead to improper or ineffective medical diagnosis and treatment.

The Hazard Communication Standard requires the Safety Data Sheet to be made readily available for workplace exposure in the United States, because this information is required by physicians so they can do their job.

Physicians also require epidemiological data maintained by local government agencies responsible for maintaining pesticide application data for use outside buildings (environmental exposure). This is part of the Right to know.

References

Industrial hygiene
Safety engineering
Environmental law in the United States