Health Hazard

Carcinogen means a chemical substance or a mixture of chemical substances which induce cancer or increase its incidence. Substances and mixtures in this hazard class are assigned to one of two hazard categories. Category 1 has two subcategories.

Respiratory sensitizer means a substance that induces hypersensitivity of the airways following inhalation of the substance. Substances and mixtures in this hazard class are assigned to one hazard category.
Reproductive toxicity includes adverse effects on sexual function and fertility in adult males and females, as well as developmental toxicity in offspring. Substances and mixtures with reproductive and/or developmental effects are assigned to one of two hazard categories: Known or Presumed” and Suspected. Category 1 has two subcategories for reproductive and developmental effects. Materials which cause concern for the health of breastfed children have a separate category: Effects on or Via Lactation.


The GHS distinguishes between single and repeat exposure for Toxic Organ Effects. Some existing systems distinguish between single and repeat exposure for these effects and some do not. All significant health effects, not otherwise specifically included in the GHS that can impair function, reversible and irreversible, immediate and/or delayed, are included in the nonlethal target organ/systemic toxicity class 9TOST). Narcotic effects and respiratory tract irritation are considered to be target organ systemic effects following a single exposure.

Substances and mixtures of the single exposure target organ toxicity hazard class are assigned to one of three hazard categories.

Substances and mixtures of the repeated exposure target organ toxicity hazard class are assigned to one of two hazard categories.

In order to help reach a decision about whether a substance should be classified or not, and to what degree it should be classified (Category 1 vs. Category 2), dose/concentration “guidance values” are provided in the GHS. The guidance values and ranges for single and repeated doses are intended only for guidance purposes. This means they are to be used as part of the weight of evidence approach and to assist with decisions about classification. They are not intended as strict demarcation values. The guidance value for repeated dose effects refers to effects seen in a standard 90-day toxicity study conducted in rats. They can be used as a basis to extrapolate equivalent guidance values for toxicity studies of greater or lesser duration.

Mutagen means an agent giving rise to an increased occurrence of mutations in populations of cells and/or organisms. Substances and mixtures in this hazard class are assigned to one of two hazard categories: Known or Presumed and Suspected or Possible. Category 1 has two subcategories.

Aspiration toxicity includes severe acute effects such as chemical pneumonia, varying degrees of pulmonary injury, or death following aspiration. Aspiration is the entry of a liquid or solid directly through the oral or nasal cavity, or indirectly from vomiting, into the trachea and lower respiratory system. Some hydrocarbons (petroleum distillates) and certain chlorinated hydrocarbons have been shown to pose an aspiration hazard in humans. Primary alcohols and ketones have been shown to pose an aspiration hazard only in animal studies.

Substances and mixtures of this hazard class are assigned to one of two hazard categories in this hazard class on the basis of viscosity.

Serious eye damage means production of tissue damage in the eye, or serious physical decay of vision, following application of a test substance to the front surface of the eye, which is not fully reversible within 21 days of application.

Eye irritation means changes in the eye following the application of a test substance to the front surface of the eye, which are fully reversible within 21 days of application.

Skin irritation means the production of reversible damage to the skin following the application of a test substance for up to four hours. Substances and mixtures in this hazard class are assigned to a single irritant category.

Skin sensitizer means a substance that will induce an allergic response following skin contact. The definition for “skin sensitizer” is equivalent to “contact sensitizer.” Substances and mixtures in this hazard class are assigned to one hazard category. Consideration should be given to classifying substances which cause immunological contact urticaria (an allergic disorder) as contact sensitizers.
Five GHS categories have been included in the GHS Acute Toxicity scheme from which the appropriate elements relevant to transport, consumer, worker, and environment protection can be selected. Substances are assigned to one of the five toxicity categories on the basis of LD50 (oral, dermal) or LC50 (inhalation).

Narcotic effects and respiratory tract irritation are considered to be target organ systemic effects following a single exposure. The GHS distinguishes between single and repeat exposure for Toxic Organ Effects. Some existing systems distinguish between single and repeat exposure for these effects and some do not. All significant health effects, not otherwise specifically included in the GHS that can impair function, reversible and irreversible, immediate and/or delayed, are included in the nonlethal target organ/systemic toxicity class 9TOST).

Substances and mixtures of the single exposure target organ toxicity hazard class are assigned to one of three hazard categories.

Substances and mixtures of the repeated exposure target organ toxicity hazard class are assigned to one of two hazard categories.

Five GHS categories have been included in the GHS Acute Toxicity scheme from which the appropriate elements relevant to transport, consumer, worker, and environment protection can be selected. Substances are assigned to one of the five toxicity categories on the basis of LD50 (oral, dermal) or LC50 (inhalation).

Skin corrosion means the production of irreversible damage to the skin following the application of a test substance for up to four hours.

Physical Hazard

Aerosols are any gas compressed, liquefied, or dissolved under pressure within a non-refillable container made of metal, glass, or plastic, with or without a liquid, paste, or powder. The container is fitted with a release device allowing the contents to be ejected as solid or liquid particles in suspension in a gas, as a foam, paste or powder, or in a liquid or gaseous state.

Aerosols should be considered for classification as either Category 1 or Category 2 Flammable Aerosol if they contain any component classified as flammable according to the GHS criteria for flammable liquids, flammable gases, or flammable solids.

Aerosols are considered:

Nonflammable: if the concentration of the flammable components < 1% and the heat of combustion is < 20 kJ/g. Extremely flammable: if the concentration of the flammable components > 85% and the heat of combustion is > 30 kJ/g to avoid excessive testing.

Flammable Gases

Flammable gas means a gas having a flammable range in air at 20 oC and a standard pressure of 101.3 kPa. Substances and mixtures of this hazard class are assigned to one of two hazard categories on the basis of the outcome of the test or calculation method (ISO 10156:1996).
Flammable Liquids

Flammable liquid means a liquid having a flash point of not more than 93 oC. Substances and mixtures of this hazard class are assigned to one of four hazard categories on the basis of the flash point and boiling point. Flash point is determined by closed cup methods as provided in the GHS document, Chapter 2.5, paragraph 11.

Flammable Solids

Flammable solids are solids that are readily combustible or may cause or contribute to fire through friction. Readily combustible solids are powdered, granular, or pasty substances which are dangerous if they can be easily ignited by brief contact with an ignition source, such as a burning match, and if the flame spreads rapidly.

Substances and mixtures of this hazard class are assigned to one of two hazard categories.

Self reactive substances are thermally unstable liquids or solids liable to undergo a strongly exothermic thermal decomposition even without participation of oxygen (air). This definition excludes materials classified under the GHS as explosive, organic peroxides, or as oxidizing. These materials may have similar properties, but such hazards are addressed in their specific endpoints.

Substances and mixtures of this hazard class are assigned to one of seven ‘Types,’ A to G.

A pyrophoric liquid is a liquid which, even in small quantities, is liable to ignite within five minutes after coming into contact with air. Substances and mixtures of this hazard class are assigned to a single hazard category.
Pyrophoric Solids

A pyrophoric solid is a solid which, even in small quantities, is liable to ignite within five minutes after coming into contact with air. Substances and mixtures of this hazard class are assigned to a single hazard category.

Self-Heating Substances

A self-heating substance is a solid or liquid, other than a pyrophoric substance, which, by reaction with air and without energy supply, is liable to self-heat. This endpoint differs from a pyrophoric substance in that it will ignite only when in large amounts (kilograms) and after long periods of time (hours or days). Substances and mixtures of this hazard class are assigned to one of two hazard categories.

Substances which, in contact with water, emit flammable gases are solids or liquids which, by interaction with water, are liable to become spontaneously flammable or to give off flammable gases in dangerous quantities. Substances in this category are assigned to one of three hazard categories.

An organic peroxide is an organic liquid or solid which contains the bivalent –O-O- structure and may be considered a derivative of hydrogen peroxide, where one or both of the hydrogen atoms have been replaced by organic radicals. The term also includes organic peroxide formulations (mixtures). Such substances and mixtures may:

be liable to explosive decomposition;
burn rapidly;
be sensitive to impact or friction;
react dangerously with other substances.

Substances and mixtures of this hazard class are assigned to one of seven ‘Types,’ A to G.

Oxidizing Gases

Oxidizing gases means any gas which may, generally by providing oxygen, cause or contribute to the combustion of other material more than air does. Substances and mixtures of this hazard class are assigned to a single hazard category on the basis that, generally by providing oxygen, they cause or contribute to the combustion of other material more than air does. Currently, several workplace hazard communication systems cover oxidizers (solids, liquids, gases) as a class of chemicals.
Oxidizing Liquids

An oxidizing liquid is a liquid which, while in itself not necessarily combustible, may, generally by yielding oxygen, cause or contribute to the combustion of other material. Substances and mixtures of this hazard class are assigned to one of three hazard categories on the basis of test results which measure ignition or pressure rise time compared to defined mixtures.
Oxidizing Solids

An oxidizing solid is a solid which, while in and of itself is not necessarily combustible, may, generally by yielding oxygen, cause or contribute to the combustion of other material. Substances and mixtures of this hazard class are assigned to one of three hazard categories on the basis of test results which measure mean burning time and are compared to defined mixtures. Currently, several workplace hazard communication systems cover oxidizers (solids, liquids, gases) as a class of chemicals.

Self reactive substances are thermally unstable liquids or solids liable to undergo a strongly exothermic thermal decomposition even without participation of oxygen (air). This definition excludes materials classified under the GHS as explosive, organic peroxides, or as oxidizing. These materials may have similar properties, but such hazards are addressed in their specific endpoints.

Substances and mixtures of this hazard class are assigned to one of seven ‘Types,’ A to G.

An organic peroxide is an organic liquid or solid which contains the bivalent –O-O- structure and may be considered a derivative of hydrogen peroxide, where one or both of the hydrogen atoms have been replaced by organic radicals. The term also includes organic peroxide formulations (mixtures). Such substances and mixtures may:

be liable to explosive decomposition;
burn rapidly;
be sensitive to impact or friction;
react dangerously with other substances.

Substances and mixtures of this hazard class are assigned to one of seven ‘Types,’ A to G.

An explosive substance (or mixture) is a solid or liquid which is in itself capable by chemical reaction of producing gas at such a temperature and pressure and at such a speed as to cause damage to the surroundings. Pyrotechnic substances are included even when they do not evolve gases. A pyrotechnic substance (or mixture) is designed to produce an effect by heat, light, sound, gas or smoke, or a combination of these as the result of non-detonative, self-sustaining, exothermic chemical reactions.

Substances, mixtures, and articles are assigned to one of six divisions, 1.1 to 1.6, depending on the type of hazard they present.

Gases under pressure are gases that are contained in a receptacle at a pressure not less than 280 Pa at 20 oC or as a refrigerated liquid. This endpoint covers four types of gases or gaseous mixtures to address the effects of sudden release of pressure or freezing which may lead to serious damage to people, property, or the environment independent of other hazards the gases may pose.

Gases are classified, according to their physical state when packaged, into one of four groups.

Skin corrosion means the production of irreversible damage to the skin following the application of a test substance for up to four hours.

Environmental Hazard

Acute Aquatic Toxicity

Acute aquatic toxicity means the intrinsic property of a material to cause injury to an aquatic organism in a short-term exposure. Substances and mixtures of this hazard class are assigned to one of three toxicity categories on the basis of acute toxicity data: LC50 (fish) or EC50 (crustacean) or ErC50 (for algae or other aquatic plants).

Chronic Aquatic Toxicity

Chronic aquatic toxicity means the potential or actual properties of a material to cause adverse effects to aquatic organisms during exposures that are determined in relation to the lifecycle of the organism. Substances and mixtures in this hazard class are assigned to one of four toxicity categories on the basis of acute data and environmental fate data: LC50 (fish) or EC50 (crustacean) or ErC50 (for algae or other aquatic plants AND degradation/bioaccumulation).