Course 601 - Essentials of Occupational Safety and Health

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Hazard Communication

More than 30 million workers in the United States are potentially exposed to one or more chemical hazards. There are an estimated 650,000 existing hazardous chemical products, and hundreds of new ones are being introduced annually. This poses a serious problem for exposed workers and their employers.

The OSHA Hazard Communication Standard (HCS) - 29 CFR 1910.1200 provides workers exposed to hazardous chemicals with the identities and hazards of those materials, as well as appropriate protective measures. When workers have such information, they are able to take steps to protect themselves from experiencing adverse effects from exposure.

Employees need to be familiar with OSHA's hazard communication standards to help save lives and avoid OSHA citations.

Look at OSHA’s Top 10 most frequently cited violations for 2018 by clicking on the image to the right.

Protection under the Hazard Communication Standard (HCS) includes all workers exposed to hazardous chemicals in all industrial sectors. This standard is based on a simple concept - that employees have both a need and a right to know the hazards and the identities of the chemicals they are exposed to when working. They also need to know what protective measures are available to prevent adverse effects from occurring.


The HCS established uniform requirements to make sure the hazards of all chemicals imported into, produced, or used in U.S. workplaces are evaluated and that this hazard information is transmitted to affected employers and exposed employees.

The standard provides necessary hazard information to employees so they can participate in, and support, the protective measures in place at their workplaces.

All workplaces where employees are exposed to hazardous chemicals must have a written plan which describes how the standard will be implemented in that facility. The only work operations which do not have to comply with the written plan requirements are laboratories and work operations where employees only handle chemicals in sealed containers.

The written program must reflect what employees are doing in a particular workplace. For example, the written plan must list the chemicals present at the site, indicate who is responsible for the various aspects of the program in that facility and where written materials will be made available to employees.

The written program must describe how the requirements for labels and other forms of warning, material safety data sheets, and employee information and training are going to be met in the facility.

Click here to review a sample of a Hazard Communication program

Purpose of the standard

The purpose of the HCS 2012 is to make sure that:

  1. the hazards of all chemicals produced or imported are classified, and
  2. information about the classified hazards is transmitted to employers and employees.

Classifying the potential hazards of chemicals, and communicating information concerning hazards and appropriate protective measures to employees, may include:

Hazard communication sign
  • developing and maintaining a written hazard communication program
  • listing hazardous chemicals present
  • labeling containers of chemicals in the workplace
  • labeling containers of chemicals being shipped to other workplaces
  • preparing and distributing SDSs to employees and downstream employers
  • developing and implementing employee training programs

The HCS 2012 applies to any chemical which is known to be present in the workplace in such a manner that employees may be exposed under normal conditions of use or in a foreseeable emergency.

cleaning chemicals in bottles

Foreseeable Emergency

"Foreseeable emergency" means any potential occurrence such as, but not limited to, equipment failure, rupture of containers, or failure of control equipment which could result in an uncontrolled release of a hazardous chemical into the workplace.

The phrase "known to be present" is important. If a hazardous chemical is known to be present by the chemical manufacturer or the employer, it is covered by the standard.

Hazardous Chemical

Worker spraying chemicals on grass

"Hazardous chemical" means any chemical which is classified as a physical hazard or a health hazard, a simple asphyxiant, combustible dust, pyrophoric gas, or hazard not otherwise classified.

This includes chemicals to which employees may be exposed during normal operations or in a foreseeable emergency. This means that even though an employer was not responsible for the manufacture of the hazardous chemical, the employer has the responsibility for transmitting information about the hazardous chemical to his or her employees.

Employees, such as office workers or bank tellers who encounter hazardous chemicals only in non-routine, isolated instances are not covered. For example, an office worker who occasionally changes the toner in a copying machine would not be covered by the standard. However, an employee who operates a copying machine as part of her/his work duties would be covered by the provisions of the HCS.

Forms of Hazardous Chemicals

Worker cutting concrete

You might think the chemicals which apply to the rule are those in liquid, gas or particulate form. However, the standard's definition of "chemical" is much broader than that commonly used. According to the HCS, chemicals that apply may exist in one of many forms:

Dusts: Finely divided particles (Example - wood dust)

Fumes: Even smaller particles usually formed when solid metal is heated and vaporized, and then condenses as tiny particles

Fibers: Similar to dusts but are of an elongated shape (Examples - asbestos and fiberglass)

Mists: Liquid droplets that have been sprayed into the atmosphere

Vapors: Gases formed when liquid evaporates

Gases: Substances which are normally airborne at room temperature. A vapor is the gaseous phase of a substance which is a normally a liquid or solid at room temperature

Solids: Such as metal, treated wood, plastic

Liquids: The most common form in the workplace

The "Prime Directive"

Employers must provide employees with effective information and training on hazardous chemicals in their work area at the time of their initial assignment, and whenever a new chemical hazard the employees have not previously been trained about is introduced into their work area. Information and training may be designed to cover categories of hazards (e.g., flammability, carcinogenicity) or specific chemicals. Chemical-specific information must always be available through labels and SDSs.



Before beginning this quiz, we highly recommend you review the module material. This quiz is designed to allow you to self-check your comprehension of the module content, but only focuses on key concepts and ideas.

Read each question carefully. Select the best answer, even if more than one answer seems possible. When done, click on the "Get Quiz Answers" button. If you do not answer all the questions, you will receive an error message.

Good luck!

1. What was the first most cited OSHA violation in FY 2018?

2. According to the text, if a hazardous chemical is known to be present by the chemical manufacturer or the employer, it is covered by the Hazard Communication standard.

3. Which of the following is the definition of "Hazardous Chemical"?

4. How many workers in the United States are potentially exposed to one or more chemical hazards?

5. Employers must provide employees with effective information and training on hazardous chemicals in their work area.

Have a great day!

Important! You will receive an "error" message unless all questions are answered.