4th Quarter 2021 – Hazard Communication



Recent changes in OHSA’s Hazard Communication Standard have brought the regulation more in line with international standards with the implementation of the Global Harmonizing System. Implementing the Global Harmonizing System, or GHS, helps ensure improved quality and consistency in the classification and labeling of all chemicals, which in turn improves an employee’s ability to quickly understand critical safety information. This program is designed to help employees understand the three key elements of the GHS: Hazard Classification, container labeling and Safety Data Sheets.



  • Hazardous chemicals—they are found in more than 7 million workplaces and over 55 million employees handle, use or work around these potentially harmful substances throughout North America.
  • While these substances are essential to many work processes in a variety of industries, they can also be very dangerous.
  • Effects from worker exposure to hazardous chemicals can range from mild skin irritation to severe burns to the eyes or skin to death from various types of exposure.
  • Hazardous chemicals can also be highly toxic, flammable or even explosive.
  • Because of the dangers presented by hazardous chemicals, The Occupational Safety and Health Administration, OSHA, developed the Hazard Communication Standard, CFR 1910.1200.
  • OSHA’s regulation requires companies to develop a Hazard Communication Program which communicates the hazards of workplace chemicals to all employees.


  • OSHA’s Hazard Communication Standard was first enacted in 1983; however, recent changes have brought the regulation more in line with international standards with the implementation of the Global Harmonizing System, or GHS for short.
  • Implementing the Global Harmonizing System helps ensure improved quality and consistency in the classification and labeling of all chemicals. This in turn improves an employee’s ability to quickly understand critical safety information.
  • Created by the international community and adopted by the United Nations, the Global Harmonizing System provides a single set of harmonized criteria for classifying chemicals and mixtures according to their health, physical and environmental hazards.
  • The Global Harmonizing System improves hazard communication by specifying communication elements, such as signal words, pictograms and precautionary statements, which are used on container labels or Safety Data Sheets.


  • Hazard Classification is the process of assigning a chemical or mixture to a hazard or danger category based on its health and physical hazards.
  • Physical hazards are the properties of a gas, liquid or solid that could adversely affect you or the workplace in a physical way, such as a fire or explosion.
  • Health hazards are determined by the properties of a substance or mixture that can cause illness or injury to the skin, eyes, lungs or other organs and body parts.
  • Because there are such a large variety of hazardous chemicals, there are also a large variety of physical and health hazards presented by these chemicals.
  • To better communicate the specific information needed by chemical workers, the Global Harmonizing System has created multiple classes of hazards. There are 16 classes of physical hazards and 10 classes of health hazards.
  • The 16 classes of physical hazards include explosives, flammable gases, aerosols, oxidizing gases, gases under pressure, flammable liquids, flammable solids and self-reactive substances and mixtures.
  • Other physical hazard classes include pyrophoric liquids, pyrophoric solids, self-heating substances and mixtures, substances and mixtures emitting flammable gases when contacting water, oxidizing liquids, oxidizing solids, organic peroxides and substances corrosive to metal.
  • The 10 classes of health hazards include acute toxicity, skin corrosion and irritation, serious eye damage or eye irritation, respiratory or skin sensitization and germ cell mutagenicity.
  • Other health hazard classes include carcinogenicity, reproductive toxicology, specific target organ toxicity from a single exposure, specific target organ toxicity from repeated exposures and aspiration hazard.
  • Of course, you may not be familiar with many of these terms and you may never work with or handle chemicals in many of these hazard classes; however, it’s important for you to understand that the existence of the various GHS hazard classes makes it easier for you to receive the specific training and important information you need to work safely with the chemicals which are located in your workplace.


  • Container labels will provide information on the relevant hazard classifications of the chemical. The labels which conform to the Global Harmonizing System may be quite different from the traditional labels you may be accustomed to seeing, so it is important to become familiar with them and the important information they deliver.
  • As part of the Global Harmonizing System, chemical manufacturers and importers are required to provide a label that includes a pictogram, harmonized signal word, hazard statements and precautionary statements for each hazard class and category.
  • Remember, the GHS standardizes all of this information based on hazard category and class to ensure that all workers, worldwide, receive consistent chemical safety information.


  • Pictograms are standardized graphics, sometimes called harmonized hazard symbols, which are assigned to a specific hazard class or category. Pictograms on a GHS label may convey health, physical or environmental hazard information.
  • Each pictogram is assigned to only one class of hazard. A pictogram will represent either a physical hazard, health hazard or environmental hazard.
  • Keep in mind that there is not a unique pictogram for each individual hazard within each class. In other words, one pictogram may be used to represent several hazards within a class.


  • There are five pictograms displayed on GHS labels to represent physical hazards of a chemical.
  • The exploding bomb pictogram is used to signify a material as an explosive, unstable explosive organic peroxide or a self-reactive substance or mixture.
  • The flame pictogram is used for flammable gases, liquids, solids and aerosols as well as self-reactive substances. It may also indicate a material is an organic peroxide, pyrophoric liquid or solid, a self-heating substance or mixture or emits flammable gases when it makes contact with water.
  • The flame over circle, or oxidizer pictogram, appears on a label when a chemical is an oxidizing gas, liquid or solid.
  • The gas cylinder pictogram is exhibited when a substance is a compressed, liquefied, refrigerated liquefied or dissolved gas.
  • The corrosion pictogram indicates a material is corrosive to metal.


  • The corrosion pictogram is also used to denote the health hazards of skin corrosion and serious eye damage.
  • Besides corrosion, there are three other health hazard pictograms. The skull and crossbones are used when a chemical is acutely toxic to the skin, lungs or digestive system.
  • The health hazard pictogram, sometimes called the chronic health hazard pictogram, denotes respiratory sensitization, germ cell mutagenicity, carcinogenicity, reproductive toxicity or an aspiration hazard. It is also used when a substance can cause specific target organ toxicity following single or repeated exposures.
  • The exclamation point pictogram is used for the health hazards of acute toxicity, skin irritation, eye irritation, skin sensitization and specific target organ toxicity following a single exposure in the form of narcotic effects or a respiratory tract infection.
  • The exclamation point is not to be used in conjunction with the skull and crossbones pictogram. It also is not used for skin or eye irritation if the corrosion pictogram also appears or if the health hazard pictogram is used to indicate respiratory sensitization.
  • A third type of pictogram is used to indicate environmental hazards. This single pictogram is used when a substance poses acute or chronic hazards to the aquatic environment.


  • Pictograms are also used when chemicals are being transported; however, the pictograms used during transport are different from those found on labels.
  • Transportation pictograms still feature the harmonized hazard symbols; however, the background, border and colors used on the transport pictogram come from in the United Nations Recommendations on the Transport of Dangerous Goods.


  • There are two signal words that appear on GHS container labels. The words “Danger” or “Warning” are used to emphasize hazards and indicate the relative level of severity of the hazard.
  • The signal word “Danger” represents a more severe hazard than the signal word “Warning”. Only one signal word, corresponding to the class of the most severe hazard, should be used on a chemical label.
  • Keep in mind that some hazard classes have not been assigned a signal word; therefore not all labels will have a signal word.


  • Other standardized communication elements found on GHS container labels are Hazard Statements and Precautionary Statements.
  • Hazard Statements are standard phrases assigned to a hazard class and category that concisely describe the nature of the hazard. For example, the Hazard Statement for an eye irritant may be “Causes eye irritation” while the Hazard Statement for a substance with acute inhalation toxicity may be “Toxic if inhaled.”
  • For products which pose more than one risk, an appropriate hazard statement for each GHS hazard will be included on the chemical label.
  • Chemical labels will also contain Precautionary Statements. Precautionary Statements are standardized explanations of the measures to be taken to minimize or prevent adverse effects.
  • There are four types of precautionary statements for each hazard class: prevention, response, storage and disposal.
  • Some examples of “Prevention” precautionary statements include “Do not allow contact with water” and “Wear protective gloves.”
  • Some examples of “Response” precautionary statements include “If on skin wash with plenty of water” and “If inhaled remove person to fresh air.”
  • Some examples of “Storage” precautionary statements include “Store in well ventilated place” and “Protect from sunlight.”
  • “Disposal” precautionary statements typically state to “Dispose in accordance to local regulations.” Disposal precautions are an area the United Nations plans to further develop in the future.


  • The product identifier is the name or number used for a hazardous substance and the label should include the chemical identity of the substance. It should match the same identifier in the Safety Data Sheet for the product.
  • Also included on the label will be the supplier identification. The name, address and telephone number should be provided.


  • Required by OSHA’s original Hazard Communications Standard, Material Safety Data Sheets have been the comprehensive source of safety information about specific chemicals; unfortunately, these valuable documents came in a wide variety of styles and formats making them hard to read and understand quickly.
  • As part of the Globally Harmonized System, they are now called “Safety Data Sheets” and have a uniform format that allows employees to obtain concise, relevant and accurate information more easily.
  • All Safety Data Sheets will have the following 16 sections, in specific order, so workers will always know which section will provide which data no matter what chemical you are referencing.
  • Section 1: Product and Company Identification—This section provides the product name and use, the manufacturer and a number to call in case of an emergency.
  • Section 2: Hazards Identification—Health, environmental and physical hazards are listed in this section. Also shown are the GHS standard and transport pictograms as well as the hazard and precautionary statements found on the container label.
  • Section 3: Composition/Information on Ingredients—This section gives the components of the substance and their concentration as well as their Chemical Abstract Service numbers, European Commission numbers and European Chemical Agency numbers.
  • Section 4: First Aid Measures—Treating chemical exposures such as contact with the eyes and skin, inhalation and ingestion are covered in this section.
  • Section 5: Firefighting Measures—This section lists the appropriate and inappropriate fire extinguisher agents to be used in the event of a fire, the exposure hazards, the combustion products and the personal protection to be worn by firefighters.
  • Section 6: Accidental Release Measure—Personal precautions, environmental precautions and methods for clean up in the event of a spill are explained in this section.
  • Section 7: Handling and Storage—This section provides the procedures for safe handling and storage of the chemical.
  • Section 8: Precautions to Control Exposure/Personal Protection—Exposure limits and the controls and monitoring required to prevent exposure above these limits are listed in this section. Also, the necessary personal protection needed to prevent exposure is also included.
  • Section 9: Physical and Chemical Properties—This section contains the various properties of the substance, such as appearance, odor, flash point, specific gravity, flammability limits and vapor density.
  • Section 10: Stability and Reactivity—Such issues as stability, hazardous decomposition products, conditions to avoid and incompatible materials are discussed in this section.
  • Section 11: Toxicological Information—This section explains the routes of entry to the human body as well as the symptoms and effects of exposure to the chemical.
  • Section 12: Ecological Information—Provided in this section is information on the product’s effect on plants or animals and its ultimate environmental disposition.
  • Section 13: Waste Disposal Considerations—This section discusses how to safely dispose of the chemical.
  • Section 14: Transport Information—The proper shipping name, hazard class, UN Identification Number, Transport Label required and other information required for transporting the product are listed in this section.
  • Section 15: Regulatory Information—This section documents the chemical’s classification under federal regulations such as the Toxic Substances Control Act, the Clean Water Act and the Superfund Amendments and Re-authorization Act among others. It may also include applicable state and international regulations as well as European Union classification and EU risk and safety phrases.
  • Section 16: Other Information—The final section allows chemical manufacturers to provide information not found in the first 15 sections. This may include such things as the manufacturer’s email address, the intended use of product, what agency issued the data sheet, date of issue, a full explanation of risk and safety phrases, just to name a few.


  • Of course, always wear the proper protective equipment specified by the container label or Safety Data Sheet. This often includes wearing gloves, protective clothing and goggles with a face shield.
  • Respiratory protection may also be required to avoid breathing in hazardous fumes.
  • If you are unsure about the required PPE for any chemical, stop and ask your supervisor.