Important Information
Canada has aligned the Workplace Hazardous Materials Information System (WHMIS) with the Globally Harmonized System of Classification and Labelling of Chemicals (GHS).
This document discusses the WHMIS supplier requirements as regulated by the federal legislation – the Hazardous Products Act and the Hazardous Products Regulations (HPR). This document reflects the Hazardous Products Regulations requirements as of December 15, 2022. The changes introduced in December 2022 are in force. Suppliers are granted a 3-year transition period (to December 15, 2025) to bring product classifications, safety data sheets and labels into compliance with the amendments.
For most workplaces, the most notable impact will be seen in the changes to the flammable gases class, and the new class of chemicals under pressure.
Health Canada is the government body responsible for the overall WHMIS supplier-related laws. Note that WHMIS is also regulated in the workplace by the provinces, territories and federal (for federally regulated workplaces) governments under their occupational health and safety legislation. While these jurisdictions based their WHMIS regulations on a common model, small variations between jurisdictions may exist.
Suppliers and employers must use and follow the WHMIS requirements for labels and safety data sheets (SDSs) for hazardous products sold, distributed, or imported into Canada.
Please refer to the following OSH Answers documents for information about WHMIS:
- WHMIS – General
- WHMIS – Pictograms
- WHMIS – Labels
- WHMIS – Safety Data Sheets (SDSs)
- WHMIS – Education and Training
- WHMIS – WHMIS Program
- WHMIS – Glossary
- WHMIS – Confidential Business Information (CBI)
- WHMIS – Variances
- WHMIS – Laboratories
What is a hazard group?
Back to topWHMIS applies to two major groups of hazards: physical, and health. Each hazard group includes hazard classes that have specific hazardous properties.
- Physical hazards group: based on the physical or chemical properties of the product – such as flammability, reactivity, or corrosivity to metals.
- Health hazards group: based on the ability of the product to cause a health effect – such as eye irritation, respiratory sensitization (may cause allergy or asthma symptoms or breathing difficulties if inhaled), or carcinogenicity (may cause cancer).
GHS also defines an Environmental hazards group. This group (and its classes) was not adopted in WHMIS. However, you may see the environmental classes listed on labels and Safety Data Sheets (SDSs). Including information about environmental hazards is allowed by WHMIS.
What is a hazard class?
Back to topHazard classes are a way of grouping together products that have similar properties. Most of the hazard classes are common to GHS and will be used worldwide by all countries that have adopted GHS. Some hazard classes are specific to WHMIS
List of Hazard Classes
Physical Hazard Classes
- Flammable gases (includes pyrophoric gases and chemically unstable gases)
- Aerosols
- Oxidizing gases
- Gases under pressure
- Flammable liquids
- Flammable solids
- Self-reactive substances and mixtures
- Pyrophoric liquids
- Pyrophoric solids
- Self-heating substances and mixtures
- Substances and mixtures which, in contact with water, emit flammable gases
- Oxidizing liquids
- Oxidizing solids
- Organic peroxides
- Corrosive to metals
- Combustible dusts
- Simple asphyxiants
- Physical hazards not otherwise classified
- Chemicals under pressure
Health Hazard Classes
- Acute toxicity
- Skin corrosion/irritation
- Serious eye damage/eye irritation
- Respiratory or skin sensitization
- Germ cell mutagenicity
- Carcinogenicity
- Reproductive toxicity
- Specific target organ toxicity – single exposure
- Specific target organ toxicity – repeated exposure
- Aspiration hazard
- Biohazardous infectious materials
- Health hazards not otherwise classified
Note: GHS also defines an Explosive class and the Environmental Hazards group (not mandatory). The WHMIS regulations do not currently include the Explosives hazard class. Explosives are covered by other legislation in Canada.
What is a hazard category?
Back to topEach hazard class contains at least one category. The hazard categories are assigned a number (e.g., 1, 2, etc.). Categories may also be called "types". Types are assigned an alphabetical letter (e.g., A, B, etc.). In a few cases, sub-categories are also specified. Subcategories are identified with a number and a letter (e.g., 1A and 1B).
Some hazard classes have only one category (e.g., corrosive to metals), others may have two categories (e.g., carcinogenicity (cancer)) or three categories (e.g., oxidizing liquids). There are a few hazard classes with five or more categories (e.g., organic peroxides).
The category tells you about how hazardous the product is (that is, the severity of hazard).
- Category 1 is always the greatest level of hazard (that is, it is the most hazardous within that class). If Category 1 is further divided, Category 1A within the same hazard class is a greater hazard than category 1B.
- Category 2 within the same hazard class is more hazardous than category 3, and so on.
There are a few exceptions to this rule. For example, for the Gases under pressure hazard class, the hazard categories are "Compressed gas", "Liquefied gas", "Refrigerated liquefied gas" and "Dissolved gas". These classes relate to the physical state of the gas when packaged and do not describe the degree of hazard.
In addition, the Reproductive Toxicity hazard class has a separate category called "Effects on or via lactation". "Effects on or via lactation" was not assigned a specific numbered category. Reproductive toxicity also has Categories 1 and 2 which relate to effects on fertility or on the unborn child. Effects on or via lactation is considered a different, but related hazard within the Reproductive toxicity class.
What are the main concerns for each physical hazard class?
Back to top| Hazard Class | General Description |
|---|---|
| Flammable gases Aerosols Flammable liquids Flammable solids | These four classes cover products that can ignite (catch fire) easily. The main hazards are fire or explosion. Note that the class Aerosols also includes a category for non-flamm |
| Oxidizing gases Oxidizing liquids Oxidizing solids | These three classes cover oxidizers, which may cause or intensify a fire or cause a fire or explosion. |
| Gases under pressure | This class includes compressed gases, liquefied gases, dissolved gases and refrigerated liquefied gases. Compressed gases, liquefied gases and dissolved gases are hazardous because of the high pressure inside the cylinder or container. The cylinder or container may explode if heated. Refrigerated liquefied gases are very cold and can cause severe cold (cryogenic) burns or injury. |
| Self-reactive substances and mixtures | These products may react on their own to cause a fire or explosion, or may cause a fire or explosion if heated. |
| Pyrophoric liquids Pyrophoric solids | These products can catch fire very quickly (spontaneously) if exposed to air. |
| Self-heating substances and mixtures | These products may catch fire if exposed to air. These products differ from pyrophoric liquids or solids in that they will ignite only after a longer period of time or when in large amounts. |
| Substances and mixtures which, in contact with water, emit flammable gases | These products react with water to release flammable gases. In some cases, the flammable gases may ignite very quickly (spontaneously). |
| Organic peroxides | These products may cause a fire or explosion if heated. |
| Corrosive to metals | These products may be corrosive (chemically damage or destroy) to metals. |
| Combustible dust | This class is used to warn of products that are finely divided solid particles. If dispersed in air, the particles may catch fire or explode if ignited. |
| Simple asphyxiants | These products are gases that may displace oxygen in the air and cause rapid suffocation. |
| Physical hazards not otherwise classified | This class is meant to cover any physical hazards that are not covered in any other physical hazard class. These hazards must have the characteristic of occurring by chemical reaction and result in the serious injury or death of a person at the time the reaction occurs. If a product is classified in this class, the hazard statement on the label and SDS will describe the nature of the hazard. |
| Chemicals under pressure | This class includes liquids or solids that are packaged in a receptacle - other than an aerosol dispenser - and that are pressurized with a gas at a gauge pressure of 200 kPa or more at 20°C but excludes any gas under pressure. |
What are the main concerns for each health hazard class?
Back to top| Hazard Class | General Description |
|---|---|
| Acute toxicity | Products classified in this hazard class are fatal, toxic or harmful if inhaled, following skin contact, or if swallowed. Acute toxicity refers to effects occurring following skin contact or ingestion exposure to a single dose, or multiple doses given within 24 hours, or an inhalation exposure of 4 hours. Acute toxicity could result from exposure to the product itself, or to a product that, upon contact with water, releases a gaseous substance that is able to cause acute toxicity. |
| Skin corrosion/irritation | This class covers products that cause severe skin burns (i.e., corrosion, ulcers, bleeding, bloody scabs, etc.) or products that cause skin irritation (reversible damage). |
| Serious eye damage/eye irritation | This class covers products that cause serious eye damage (i.e., tissue damage in the eye or serious physical decay of vision) or products that cause eye irritation (reversible damage). |
| Respiratory or skin sensitization | A respiratory sensitizer is a product that may cause allergy or asthma symptoms or breathing difficulties if inhaled (hypersensitivity). Skin sensitizer is a product that may cause an allergic response after skin contact. |
| Germ cell mutagenicity | This hazard class includes products that may cause or are suspected of causing heritable gene mutations (permanent changes (mutations) to body cells that can be passed on to future generations). |
| Carcinogenicity | This hazard class includes products that may lead to cancer or may increase the incidence of cancer. |
| Reproductive toxicity | This hazard class includes products that may damage or are suspected of damaging sexual function and fertility, have adverse effects on the unborn child (embryo, fetus, or offspring), or may have an effect on or through lactation (such as cause harm to breast-fed children). |
| Specific target organ toxicity – single exposure | This hazard class covers products that cause or may cause damage to organs (e.g., liver, kidneys, or blood) following a single exposure. This class also includes a category for products that cause respiratory irritation or drowsiness or dizziness. |
| Specific target organ toxicity – repeated exposure | This hazard class covers products that cause or may cause damage to organs (e.g., liver, kidneys, or blood) following prolonged or repeated exposure. |
| Aspiration hazard | Aspiration is defined as the entry of a liquid or solid into the trachea or lower respiratory system directly though the oral or nasal cavity, or indirectly by vomiting. In other words, aspiration occurs when instead of something going from your mouth or nose to your stomach (other than air), it enters the lungs. Serious health effects can occur such as chemical pneumonia, injury to the lungs, and death. |
| Biohazardous infectious materials | These materials are microorganisms, nucleic acids or proteins that cause or are a probable cause of infection, with or without toxicity, in humans or animals. |
| Health hazards not otherwise classified | This class covers hazards that are not included in any other health hazard class. These hazards occur following acute or repeated exposure and have an adverse effect on the health of a person exposed to them. The adverse effects include injuries or death of that person. If a product is classified in this class, the hazard statement will describe the nature of the hazard. |
How will I know what hazard class or category is assigned to a hazardous product?
Back to topSuppliers must evaluate products that are covered by the Hazardous Products Act against specific criteria as required by the Hazardous Products Regulations. If the product meets any of the criteria for a hazard class, it is known as a hazardous product. All hazardous products must be labelled according to the regulations, and must have a corresponding Safety Data Sheet (SDS). The hazard class and category will be provided in Section 2 (Hazard Identification) of the SDS. Each hazard class or category must use specific pictograms and other label elements to indicate the hazard that is present, and what precautionary measures must be taken. Use the information provided by the label and SDS to be informed and to know how to safely use, handle, store and dispose of the hazardous product.
- Fact sheet last revised: 2023-03-15
FAQs
What are the 6 WHMIS hazard classes? ›
- Compressed Gas.
- Flammable and Combustible Material.
- Poisonous and Infectious Material.
- Corrosive Material.
- Dangerously Reactive Material.
- Acute toxicity.
- Aspiration hazard.
- Biohazardous infectious materials.
- Carcinogenicity.
- Germ cell mutagenicity.
- Reproductive toxicity.
- Respiratory or skin sensitization.
- Serious eye damage/eye irritation.
There are a few hazard classes with five or more categories (e.g., organic peroxides) 23 Page 24 24 Hazard Categories • The Hazard Category tells you about how hazardous the product is (that is, the severity of hazard). Category 1 is always the greatest level of hazard within its class.
What is hazard classification class A? ›What is a Class A - Compressed Gas? Any material that is normally a gas which is placed under pressure or chilled, and contained by a cylinder is considered to be a compressed gas. These materials are dangerous because they are under pressure.
What are the 9 hazard classes? ›- Class 1: explosives.
- Class 2: gases.
- Class 3: flammable liquids.
- Class 4: flammable solids.
- Class 5: organic peroxides and oxidizing substances.
- Class 6: infectious or toxic substances.
- Class 7: radioactive material.
- Class 8: corrosives.
There are many types of hazards - chemical, ergonomic, physical, and psychosocial, to name a few - which can cause harm or adverse effects in the workplace. Get resources on specific hazards and their control, including identification, risk assessment and inspections, to keep your workplace healthy and safe.
What is a Category 3 health hazard? ›Risk level 3: Materials extremely hazardous to health, but areas may be entered with extreme care. Full protective clothing including self-contained breathing apparatus, coat, pants, gloves, and boots, with bands around the legs, arms, and waist should be provided. No skin surface should be exposed.
What is hazard Category 4? ›Hazard Class 4: Flammable Solids.
What does hazard class 5 mean? ›5.1 Oxidizers means a material that may, generally by yielding oxygen, cause or enhance the combustion of other materials.
What is the difference between hazard groups and categories? ›Class – Class is the term used to describe the different types of hazards. For example, Gases under Pressure is an example of a class in the physical hazards group. Category – Category is the name used to describe the sub-sections of classes. For example, Self-Reactive Chemicals have 7 categories.
What are Class A and Class B hazards? ›
Class A: Ordinary solid combustibles such as paper, wood, cloth and some plastics. Class B: Flammable liquids such as alcohol, ether, oil, gasoline and grease, which are best extinguished by smothering.
Are there 7 named classes of hazardous materials? ›A visor card guide for state and local law enforcement officials illustrating vehicle placarding and signage for the following nine classes of hazardous materials: 1) Explosives, 2) Gases, 3) Flammable Liquid and Combustible Liquid, 4) Flammable Solid, Spontanaeously Combustible and Dangerous When Wet 5) Oxidizer and ...
What is the correct order of elements in WHMIS classification system? ›The main components of WHMIS are hazard identification and product classification, labelling, safety data sheets, and worker education and training.
What is hazard class C? ›Class C Hazard: 2. A condition or practice likely to cause serious injury or illness, resulting in temporary disability or property damage that is disruptive but not extensive. For example, spilled oil on the main aisle.
Is Category 1 or 4 worse? ›Category 1 is always the greatest level of hazard (that is, it is the most hazardous within that class).
What are Class 1 hazardous materials? ›Hazmat Class 1 are explosive materials which are any substance or article, including a device, which is designed to function by explosion or which, by chemical reaction within itself is able to function in a similar manner even if not designed to function by explosion.
How do you remember hazard classes? ›An easy way to remember the 6 sub divisions of class one is the Acronym Many, People, Find, Me, Very, Exciting. Now that we have a better foundational understanding of what we may be shipping or transporting, we can certainly answer the “WHO” portion of hazardous materials.
What is a Class 6 hazard? ›Hazard Class 6: Class 6 hazards are poisonous materials. These substances are divided into two classes: poisonous substances and biohazardous substances, and are designated by 6.1 and 6.2, respectively.
How many physical hazard categories are there? ›There are five main classes of physical hazard namely Explosive, Flammable, Oxidising, Gases under Pressure and Corrosive to metals.
What are the key elements of WHMIS? ›WHMIS is a comprehensive plan for providing information on the safe use of hazardous materials used in Canadian workplaces. The (three) 3 principal elements of WHMIS that are used to provide information to employers and workers are Labels, Material Safety Data Sheet (MSDS), and Worker Education programs.
What is a Category 2 health hazard? ›
| Pictogram | Hazard Class | Category |
|---|---|---|
| Exclamation Mark | Eye irritation | Category 2A |
| Skin irritation | Category 2 | |
| Acute Toxicity, oral | Category 4 | |
| Sensitization, skin | Category 1 |
Class 1 - Extreme (death from any cause, permanent loss of consciousness, regular severe pneumonia, 80% burn injuries) Class 2 - Severe (cardio-respiratory disease, asthma, loss of a hand or foot, serious factures, severe burns)
What is hazard category 1 4? ›0-4 0-least hazardous 4-most hazardous 1-4 1-most severe hazard 4-least severe hazard • The Hazard category numbers are NOT required to be on labels but are required on SDSs in Section 2. Numbers are used to CLASSIFY hazards to determine what label information is required.
What are Class 2 hazardous materials? ›Class 2 hazards are compressed gases, which are divided into four categories: flammable/combustible gases, non-flammable/non-poisonous gases, toxic/poisonous gases, and oxygen.
What does GHS Category 1 mean? ›Respiratory sensitizers are classified into GHS Hazard Category 1 if: “(a) there is evidence in humans that the chemical can lead to specific hypersensitivity; and/or (b) if there are positive results from an appropriate animal test” (UNECE 2013).
What is Category 1 acute toxicity? ›Toxicity category I is highly toxic and severely irritating, Toxicity category II is moderately toxic and moderately irritating, Toxicity category III is slightly toxic and slightly irritating, Toxicity category IV is practically non-toxic and not an irritant.
What is 5.2 hazard class? ›Class 5.2 – Organic peroxides
Thus the fuel and the oxygen are together in the same molecule, making them even more liable to ignition than a separate combustible material. They are designed to be reactive for a number of industrial purposes, and may consequently be unstable, and sometimes explosive.
Class 6 Dangerous Goods - Toxic Substances; Infectious Substances. Toxic substances are those which are liable either to cause death or serious injury or to harm human health if swallowed, inhaled or by skin contact. Infectious substances are those which are known or can be reasonably expected to contain pathogens.
What are some examples of hazard class 1? ›Hazard Class 1: Class 1 hazards are explosives or any devices or chemicals that are designed to explode or combust.
What is the GHS code? ›GHS hazard statement means a standard phrase assigned to a hazard class and category to describe the nature and severity of a chemical hazard. Each hazard statement is designated a code, starting with the letter H and followed by 3 digits.
How many hazard classes are there in the WHMIS? ›
Hazardous products are divided into two hazard groups: physical hazards and health hazards.
What do the letters SDS stand for? ›A Safety Data Sheet (formerly called Material Safety Data Sheet) is a detailed informational document prepared by the manufacturer or importer of a hazardous chemical. It describes the physical and chemical properties of the product.
What are Class 1 Class 2 Class 3 hazardous locations? ›Class Definition
Class I locations are those in which flammable vapors and gases may be present. Class II locations are those in which combustible dust may be found. Class III locations are those which are hazardous because of the presence of easily ignitable fibers or flyings.
Class A: solid materials such as wood or paper, fabric, and some plastics. Class B: liquids or gas such as alcohol, ether, gasoline, or grease. Class C: electrical failure from appliances, electronic equipment, and wiring. Class D: metallic substances such as sodium, titanium, zirconium, or magnesium.
What is a Class 1 explosive hazard? ›Hazard Class 1: Class 1 hazards are explosives or any devices or chemicals that are designed to explode or combust. Class 1 explosives are illustrated by an orange placard with their designated hazard class, division number or compatibility letter displayed at the bottom. Some also feature an explosion graphic.
What does an orange placard mean? ›Orange represents explosive materials which can include products like dynamite, fireworks and ammunition. These signs typically have the words explosives or blasting agents on them and a graphic indicating something blowing up. They'll also have the number 1 to indicate the class.
What is a dot placard? ›DOT Placards are larger, more durable versions of hazard labels that are usually placed on bulk packages or transport vehicles to communicate the hazards of chemicals inside. This is why placards are used.
How many hazard classes are fully regulated? ›Each of the nine hazard classes for fully regulated items in the United States has specific handling, storage, and transportation requirements and special considerations or rules that apply to certain materials or situations.
How many classifications are WHMIS labels divided into? ›There are two main types of WHMIS labels: supplier labels, and workplace labels. Suppliers of hazardous products are required to apply a label that meets the requirements of the Hazardous Products Regulations.
What are the 3 main types of labels used in the WHMIS program? ›- SUPPLIER LABELS. Supplier labels come from the manufacturer of the controlled product and are usually located on the back of the container. ...
- WORKPLACE LABELS. ...
- LABORATORY LABELS.
How many hazard symbols are there in WHMIS? ›
It may have felt daunting to learn 9 distinct symbols related to chemicals you occasionally encounter, but the recognition and knowledge of these WHMIS symbols, continues to be a necessity for employers to ensure safety standards are met in the Canadian workplace.
What is a Class 6 hazard label? ›Labelmaster's Hazard Class 6 Labels have you covered. Available in Worded or International Wordless, Personalized with a Shipping Name or with Blank tabs, these labels are ideal when transporting toxic substances such as medical waste, dyes, acids and carbamate pesticides, which can contain disease-spreading pathogens.
What are the WHMIS hazard symbols? ›- Exploding Bomb (Explosion or reactivity hazards) ...
- Flame (Fire hazard) ...
- Flame Over Circle (Oxidizing hazards) ...
- Gas Cylinder (Gases under pressure) ...
- Corrosion (Corrosive damage to metals, skin, eyes) ...
- Skull & Crossbones (Can cause death or toxicity with short exposure to small amounts)
Supplier labels provide seven (7) pieces of information: Product Identification (brand name, code name or chemical name) WHMIS Hazard Symbols for each of product's hazard classes. Risk Phrases (words that describe the main hazards of the product)
What are Class 7 hazardous materials? ›Class 7 dangerous goods are radioactive materials. There is no sub-division. However, there are different labels for radioactive materials which depend on the content and activity of such materials.
What is 6.1 hazard classes? ›Hazard Class 6.1: Toxic (also Poison)
What is a 6.2 hazard class? ›A Division 6.2 infectious substance is a material known or reasonably expected to contain a pathogen. A pathogen is a micro-organism (including bacteria, viruses, rickettsia, parasites, fungi) or other agent, such as a proteinaceous infectious particle (prion), that can cause disease in humans or animals.
What are Class 5 hazardous materials? ›Class 5 Dangerous Goods Examples
Commonly transported class 5 dangerous goods include hydrogen peroxide, potassium permanganate, sodium nitrite, ammonium nitrate fertilizers and oxygen generators.
What are the main parts of WHMIS? The main components of WHMIS are hazard identification and product classification, labelling, safety data sheets, and worker education and training.
What is the correct order in the WHMIS classification system? ›- Flammable gases.
- Flammable aerosols.
- Oxidizing gases.
- Gases under pressure.
- Flammable liquids.
- Flammable solids.
- Self-reactive substances and mixtures.
- Pyrophoric liquids.
What is required on a WHMIS label? ›
Under WHMIS, supplier labels for hazardous workplace products must display the product identifier and supplier identifier, as well as hazard pictogram(s), signal word, hazard statement(s), and precautionary statement(s) assigned based on the hazard classification.
What are the 3 main elements of WHMIS? ›The (three) 3 principal elements of WHMIS that are used to provide information to employers and workers are Labels, Material Safety Data Sheet (MSDS), and Worker Education programs.
What are the two signal words for WHMIS? ›There are only two signal words used: "Danger" or "Warning". "Danger" is used for high-risk hazards, while "Warning" is used for less severe hazards.
What are the 3 types of WHMIS labels? ›- SUPPLIER LABELS. Supplier labels come from the manufacturer of the controlled product and are usually located on the back of the container. ...
- WORKPLACE LABELS. ...
- LABORATORY LABELS.