Chemical substances glossary

1. A
2. B
3. C
4. D
5. E
6. F
7. G
8. H
9. I
10. J
11. K
12. L
13. M
14. N
15. O
16. P
17. Q
18. R
19. S
20. T
21. U
22. V
23. W
24. Y
25. X
26. Z

A

Accession number

A unique designation assigned to a micro-organism when it is submitted to an internationally recognized culture collection (for example, American Type Culture Collection). The accession number can also be an experimental or proprietary designation.

Adverse effect

An undesirable or harmful change in the morphology, physiology, growth, development, reproduction or lifespan of an organism or population of organisms.

Adverse outcome pathway (AOP)

An AOP is a toxicity pathway composed of a sequence of causally-linked events that lead to a specific adverse health effect in humans or other organisms. An AOP begins with a chemical interacting with a biological target (this step is called a molecular initiating event), leading to a series of key events occurring at different levels of biological organization along the toxicity pathway, and resulting in an adverse outcome. AOPs can provide mechanistic information for chemical risk assessment.

Analogue substances

Substances that are similar to the assessed substance based on chemical structure, physico-chemical and biological properties, and/or function.

Animate substance

Substance that is living.

Anthropogenic

Caused by human activity.

Assessment

A scientific evaluation of a substance under the Canadian Environmental Protection Act, 1999 (CEPA) to determine the potential harm or danger it can cause to human health and the environment, and the ways in which it can happen. This allows the federal government to identify the control measures needed to reduce or prevent the potential harm.

B

Bioaccumulation, or B

The process of gradual accumulation of substances in living tissues.

Bioaccumulative and inherently toxic (BiT)

A designation for certain substances that met the regulatory criteria for bioaccumulation and a threshold for inherent toxicity during categorization of the Domestic Substances List.

Biomagnification

The process of increasing concentrations of a substance in the tissue of organisms at successively higher levels in the food chain.

Biotechnology

The application of science and engineering in the direct or indirect use of living organisms or parts or products of living organisms in their natural or modified forms. As defined in the Canadian Environmental Protection Act, 1999 (CEPA), biotechnology is not limited to activities involving genetic engineering. Living organisms subject to Part 6 of CEPA must be animate products of biotechnology and can be either naturally occurring or genetically modified.

By-product

A secondary product derived from a production process, manufacturing process or chemical reaction; it is not the primary product being produced.

C

Canadian Environmental Protection Act, 1988 and 1999 (CEPA, CEPA 1988 and CEPA 1999)

CEPA is "an Act respecting pollution prevention and the protection of the environment and human health in order to contribute to sustainable development". CEPA was first passed in 1988. A review in 1999 and amendments made in 2023 further strengthened human health and environmental protection components.

Carcinogen

A substance that has the capacity to cause cancer (for example, cancerous cells or cancerous tumors).

Categorization

A process, completed in 2006, used to identify substances on the original Domestic Substances List (DSL) that may be of concern and warrant further examination. The original DSL is a list of substances that were in commerce in Canada between 1984 and 1986.

Chemical Abstracts Service Registry Number (CAS RN)

The CAS RN is a unique identifier that provides an unambiguous means to distinguish substances or molecular structures. It is the property of the American Chemical Society and any use or redistribution, except as required in supporting regulatory requirements and/or for reports to the Government of Canada when the information and the reports are required by law or administrative policy, is not permitted without the prior written permission of the American Chemical Society.

Chemical Substance

Elements or compounds that are deliberately created, produced as a by-product of other processes or occurring naturally in the environment.

Circular economy

A way of doing business that extracts as much value as possible from resources by recycling, repairing, reusing, repurposing, or refurbishing products and materials—eliminating waste and greenhouse gas emissions at the design stage. Businesses can use circular designs to save money or open up new market opportunities, from turning waste into renewable bioproducts, to launching product buy-back programs that enhance customer interaction and recover usable materials.

Class of substances and a "class-based" approach

As defined in the Canadian Environmental Protection Act, 1999, a class of substances means any two or more substances that:

1. contain the same portion of chemical structure;
2. have similar physico-chemical and/or toxicological properties; or
3. for the purposes of sections 68, 70 and 71, have similar types of use.

A class-based approach is an approach used to assess or manage multiple chemicals that have similar or shared chemical structures or physico-chemical properties.

Confidential Accession Number

A number assigned by Environment and Climate Change Canada to identify confidential substances on the Domestic Substances List.

Consumer product

As defined in the Canada Consumer Product Safety Act, consumer product means a product, including its components, parts or accessories, that may reasonably be expected to be obtained by an individual to be used for non-commercial purposes, including for domestic, recreational and sports purposes, and includes its packaging.

Cosmetic

As defined in the Food and Drugs Act, cosmetic includes any substance or mixture of substances manufactured, sold or represented for use in cleansing, improving or altering the complexion, skin, hair or teeth, and includes deodorants and perfumes.

D

Domestic Substances List (DSL)

An inventory of substances manufactured in, or imported into Canada on a commercial scale. It was originally published in the Canada Gazette Part II on May 4, 1994 and included approximately 23,000 substances deemed to have been in Canadian commerce between January 1984 and December 1986. The DSL is amended, on average, 12 times per year to add, update or delete substances. See also the Domestic Substances List.

E

Ecological risk classification of organic substances (ERC) Approach

Approach used by Environment and Climate Change Canada to characterize organic substances for their potential to cause ecological harm. It is a risk-based approach that employs multiple metrics for both hazard and exposure, with weighted consideration of multiple lines of evidence for determining risk classification and to identify substances of higher priority for future regulatory activities such as further data gathering and risk assessment. There are 2 versions of the approach published. In 2016, ERC1 ranked 640 organic substances into 3 levels of concern. In 2021, ERC2, increased the sophistication of the ERC Approach and classified the level of concern for approximately 12,200 organic substances. The ERC Approaches and the results of their application are available on the science approach documents web page.

Endocrine-disrupting substance

A chemical substance that has the ability to disrupt the synthesis, secretion, transport, binding, action or elimination of natural hormones in an organism, or its progeny, that are responsible for the maintenance of homeostasis, reproduction, development or behaviour of the organism.

Environmental performance agreement

A type of voluntary agreement developed among one or more orders of government and a company or an industry sector. It sets out the specific actions to manage risks from a chemical substance or group of chemical substances.

Existing substances

Substances listed on the Domestic Substances List (DSL). Since 1994, Health Canada and Environment and Climate Change Canada have been assessing and managing the health and environmental risks of all new substances not listed on the DSL, before allowing their import into or manufacture in Canada. However, many substances were introduced into Canada prior to 1994. Many of these older, or "existing" substances had not been examined for their potential risks by environmental and health scientists in government. Approximately 23 000 existing substances were registered on the original Domestic Substances List (DSL). As part of the Chemicals Management Plan, Health Canada and Environment and Climate Change Canada assess these substances and take action on the substances found to be harmful to human health and/or the environment.

Exposure

The degree to which the environment or living things, including people, come into direct or indirect contact with a substance. Health Canada assesses potential exposure of the general population to substances from all routes (inhalation, ingestion and contact with the skin) and all possible sources (ambient and indoor air, water, food, breast milk, soil, and household and consumer products). Environment and Climate Change Canada assesses exposure in environmental media (that is, water, air, sediment, soil), wastewater, and wildlife.

G

Greatest potential for exposure (GPE)

Criterion used in categorization of the Domestic Substances List (DSL) to help determine if a substance needed further assessment. GPE was developed to indicate the extent to which humans could come into contact with a given substance, based on information reported by industry during the compilation of the DSL.

H

Hazard

Hazard is the potential harm that a substance can cause, whether this harm could be to human health or to the environment.

Health Canada automated workflow for prioritization (HAWPr)

A computational tool used by Health Canada that integrates inputs across various information sources and scripting languages, as well as conducts analytics on large data sets. It is a risk-based approach that employs multiple metrics for both hazard and exposure to identify substances of higher priority for future regulatory activities such as further data gathering and risk assessment. The HAWPr Approach and results are available on the science approach documents web page.

High production volume (HPV)

A category that defines chemicals manufactured in, or imported into, the U.S. in amounts equal to or greater than one million pounds per year. The U.S. Environmental Protection Agency HPV Challenge Program was a collaborative partnership to provide the public with access to information allowing it to actively participate in environmental decision-making.

I

Identification of risk assessment priorities (IRAP)

An approach for identification of chemicals and polymers as risk assessment priorities under Part 5 of the Canadian Environmental Protection Act, 1999. This approach is a cyclical and systematic compilation and review of information from a large number of information sources in order to identify substances of concern that warrant further review. It enables the Government of Canada to communicate how emerging issues are tracked, and to identify and prioritize substances requiring further consideration.

Informed substitution

The considered transition from use of a substance of concern to safer substances or non-chemical alternatives. It is an internationally recognized strategy for reducing health and environmental risks posed by substances.

Inherently toxic (iT)

Substances that are, by their very nature, known or suspected, through laboratory and other studies, to have a harmful effect on human life or wildlife and the natural environment on which they depend. It is also a designation that indicates that a substance met the toxicity threshold for inherent toxicity as part of categorization of the Domestic Substances List.

Intermediate

In a chemical reaction or mechanism, a molecule that is formed and then reacts further to produce other substances. It is a chemical substance used to make other substances or products, and which is consumed in part or completely during the process.

L

List of toxic substances

See Schedule 1.

Living organisms

Living organism is defined in section 104 of the Canadian Environmental Protection Act, 1999 as a substance that is an animate product of biotechnology. Organisms are classified either as micro-organisms (bacteria, virus, etc.) or organisms other than micro-organisms (fish, mammal, etc.).

M

Margin of exposure (MOE)

A measure of potential risk to human health from a substance in a specific exposure scenario. The MOE is a ratio calculated by dividing a level at which harm to human health is not expected (such as a no-observed-adverse-effect-level) by the estimated level of human exposure.

Micro-organism

The New Substances Notification Regulations (Organisms) defines a micro-organism as a microscopic organism that is

1. classified in the Bacteria, the Archaea, the Protista, which includes protozoa and algae, or the Fungi, which includes yeasts;
2. a virus, virus-like particle or sub-viral particle;
3. a cultured cell of an organism not referred to in paragraph (a) or (b), other than a cell used to propagate the organism; or
4. any culture other than a pure culture.

Monomer

A substance that is a building block for polymers.

Mutagenic

Property of a substance that can cause changes to the DNA of cells.

N

Nanomaterials

Any manufactured substance or product and any component material, ingredient, device, or structure is considered to be a nanomaterial if:

1. it is at or within the nanoscale in at least one external dimension, or has internal or surface structure at the nanoscale; or
2. it is smaller or larger than the nanoscale in all dimensions and exhibits one or more nanoscale properties/phenomena.

For more information, refer to part 4.1 of Health Canada's working definition. The risk assessment of a nanomaterial under the Canadian Environmental Protection Act, 1999 is conducted separately from its bulk form.

New approach methods (NAMs)

NAMs are broadly defined to include any technology, methodology, approach or combination thereof that can be used to replace, reduce or refine animal toxicity testing and allow for more rapid or effective prioritization and/or assessment of chemicals. These methods may include the use of computer-based (computational) models, modernized whole-organism assays, or assays with biological molecules, cells, tissues or organs, as well as exposure prediction approaches. While some of these methods are quite new, others have been available for some time, but are now being put to new uses. NAMs can be used to improve understanding of the mechanisms underpinning adverse effects and to identify doses below which effects are not expected to occur from a human or ecological toxicity perspective. Data generated by NAMs are increasingly being used to provide hazard, exposure and risk information for prioritizing chemicals for further action and can contribute to the weight of evidence in chemical risk assessments. Additionally, NAM data can highlight where further testing may be needed in an integrated or tiered testing strategy.

New substances

Substances that are not presently on the Domestic Substances List are considered to be new to Canada. The New Substances Notification Regulations (Chemicals and Polymers) and the New Substances Notification Regulations (Organisms)were created to ensure that new substances (chemicals, polymers and living organisms) are assessed for potential risks to human health and the environment and, if required, control measures are put in place before they are introduced into the Canadian marketplace. See also New Substances program.

Non-Domestic Substances List

Environment and Climate Change Canada has published and continues to maintain a Non-Domestic Substances List (NDSL). This list is based on the US Environmental Protection Agency's Toxic Substances Control Act chemical substances inventory for 1985, and contains more than 58 000 entries. Substances that are not on the Domestic Substances List (DSL) but are listed on the NDSL are subject to lesser information requirements under the New Substances Notification Regulations (Chemicals and Polymers).

O

Occupational exposure

Exposure to substances in the workplace. This may include direct exposures to those handling substances in the workplace or those who may be exposed indirectly.

P

Pathogen

Any disease-producing micro-organism.

Persistent

Refers to a substance that remains in the environment for a long time. A substance is considered persistent if it meets the criteria listed in the Persistence and Bioaccumulation Regulations.

Persistent, bioaccumulative and inherently toxic (PBiT)

A designation for certain substances that met the regulatory criteria for persistence and bioaccumulation and a threshold for inherent toxicity during categorization of the Domestic Substances List.

Persistent and inherently toxic (PiT)

A designation for certain substances that met the regulatory criteria for persistence and a threshold for inherent toxicity during categorization of the Domestic Substances List.

Point of departure (PoD)

A dosage or concentration of a single substance used to estimate tolerable exposures to humans. The point of departure is typically based on a lowest observed adverse effect level or concentration, no observed adverse effect level or concentration, or benchmark dose.

Pollution prevention (P2)

Pollution prevention is a fundamental principle of the Canadian Environmental Protection Act, 1999. It refers to the use of processes, practices, materials, products, substances or energy that avoid or minimize the creation of pollutants and waste and reduce the overall risk to the environment or to human health.

Pollution prevention plans (P2 plans)

A systematic, comprehensive method of identifying options to minimize or avoid the creation of pollutants or waste. The goal of pollution prevention planning is to have a company or facility select the measures that are most appropriate for its specific circumstances to reduce the use, generation and release of specific substances.

Polymer

A substance that has a molecular structure consisting partially or entirely of a large number of similar units, or building blocks, bonded together.

The New Substances Notification Regulations (Chemicals and Polymers) defines a "polymer" as a substance that consists of

1. molecules characterized by the sequence of one or more types of monomer units;
2. greater than 50% by weight of molecules having three or more monomer units that are covalently bound to one or more other monomer units or reactants;
3. less than 50% by weight of molecules of the same molecular weight; and
4. molecules distributed over a range of molecular weights whose differences in molecular weights are primarily attributable to differences in the number of monomer units.

Precautionary principle

The precautionary principle is one of the foundations on which the Canadian Environmental Protection Act, 1999 is based. It refers to Principle 15 of the 1992 Rio Declaration on Environment and Development, which states that lack of full scientific certainty shall not be used as a reason to postpone cost-effective measures that prevent environmental degradation if there are threats of serious or irreversible damage.

Priority Substances List (PSL)

Prior to the June 2023 amendments, the Canadian Environmental Protection Act, 1999 (CEPA) contained provisions for a PSL that required substances to be investigated on a priority and in-depth basis to determine if they were toxic under CEPA. Substances could be added to the PSL following a screening assessment decision or review of another government's assessment, or at the request of any person (under certain conditions).

Problem formulation

A problem formulation summarizes key information for a substance, or group of substances, of potential concern in order to scope and define the issues and propose future actions. It can also provide an opportunity for early engagement with stakeholders in the context of identifying priorities for future action.

R

Read-across

Read-across is a technique that involves using experimental or model data from structurally or functionally similar substances (analogue substances) to predict the behaviour of a substance being assessed (the target substance).

Registration, Evaluation and Authorisation of Chemicals (REACH)

REACH is a regulation of the European Union, adopted to improve the protection of human health and the environment from the risks that can be posed by chemicals, while enhancing the competitiveness of the EU chemicals industry. It came into force in June 2007.

Regulatory impact analysis statement (RIAS)

The RIAS provides information to people in Canada and decision-makers on regulatory decisions and their impacts in order to protect and advance the public interest in health, safety and security, the quality of the environment, and the social and economic well-being of people in Canada.

Risk

The risk posed by a substance is a function of its hazardous properties and the ways in which people and the environment are exposed to the substance.

Residual

The material remaining after a process of preparation, separation, or purification. It may also denote the undesired by-products of a chemical reaction.

Revised In Commerce List (R-ICL)

The R-ICL is comprised of substances which were in products that were regulated under the Food and Drugs Act and that were in Canadian commerce between January 1, 1987 and September 13, 2001. Since September 2001, substances in products regulated under the Food and Drugs Act have been subject to the New Substances Notification Regulations of the Canadian Environmental Protection Act, 1999.

Risk assessment

See assessment.

Risk management

Under the Canadian Environmental Protection Act, 1999, risk management is the decision making process to identify, evaluate, select and implement actions to reduce risk to human health and the environment. Risk management includes pollution prevention, control, reduction or elimination of a toxic substance.

Risk management tool

Under the Canadian Environmental Protection Act, 1999, risk management tools include regulations, pollution prevention plans, environmental emergency plans, administrative agreements, codes of practice, environmental quality objectives or guidelines, release guidelines, deposit-refund systems and tradeable permits. Tools specific to new substances not listed on the Domestic Substances List include ministerial conditions, ministerial prohibitions, and ministerial requests for additional information.

S

Screening assessment

See assessment.

Schedule 1

This is a list of substances that are considered to be toxic as defined in section 64 of the Canadian Environmental Protection Act, 1999 (CEPA). Adding a substance to Schedule 1 enables the Government to take enforceable risk management actions under CEPA, using a two-track approach to manage risks:

Toxic substances that pose the highest risk are added to Part 1 of Schedule 1. These are prioritized for total, partial or conditional prohibition.

Other toxic substances are added to Part 2 of Schedule 1 and are prioritized for pollution prevention.

For the complete listing of these substances, see Schedule 1. To note: Schedule 1 may also be referred to as the "toxic substances list" on this website.

Section 64 of the Canadian Environmental Protection Act, 1999 (CEPA)

Section 64 of the CEPA defines a substance as toxic "if it is entering or may enter the environment in a quantity or concentration or under conditions that:

1. have or may have an immediate or long-term harmful effect on the environment or its biological diversity;
2. constitute or may constitute a danger to the environment on which life depends; or
3. constitute or may constitute a danger in Canada to human life or health."

Significant new activity (SNAc) provisions

The SNAc provisions of the Canadian Environmental Protection Act, 1999 trigger an obligation for a person to provide the Government of Canada with information about a substance when proposing to use, import or manufacture the substance for a significant new activity. The government then assesses the substance for potential risks to human health and/or the environment. If risks are identified, the government may impose management measures.

Species sensitivity distribution (SSD)

A statistical approach that uses the distribution of data from toxicity tests with various species to estimate the hazardous concentration of a substance that will affect no more than a certain percentage (typically 5%) of all species (referred to as the HCx, where x is the percentage of species affected).

Strain

A group of clonally-derived or otherwise indistinguishable micro-organisms within a species but that differ in characteristics (and are distinguishable) from other similar groups (strains) within the same species.

Substance

The Canadian Environmental Protection Act, 1999  defines a "substance" as any distinguishable kind of organic or inorganic matter, whether animate or inanimate, and includes:

1. any matter that is capable of being dispersed in the environment or of being transformed in the environment into matter that is capable of being so dispersed or that is capable of causing such transformations in the environment
2. any element or free radical
3. any combination of elements of a particular molecular identity that occurs in nature or as a result of a chemical reaction; and
4. complex combinations of different molecules that originate in nature or are the result of chemical reactions but that could not practicably be formed by simply combining individual constituents
   and, except for the purposes of sections 66 to 66.2, 80 to 89 and 104 to 115, includes:
5. any mixture that is a combination of substances but does not itself produce a substance that is different from the substances that were combined
6. any manufactured item that is formed into a specific physical shape or design during manufacture and has, for its final use, a function or functions dependent in whole or in part on its shape or design; and
7. any animate matter that is, or any complex mixtures of different molecules that are, contained in effluents, emissions or wastes that result from any work, undertaking or activity.

T

Toxic Substances List: Schedule 1

See: Schedule 1.

Toxic under the Canadian Environmental Protection Act, 1999 (CEPA 1999)

See section 64 of the Canadian Environmental Protection Act, 1999.

U

Unknown or variable composition, complex reaction products or biological materials (UVCB).

These substances cannot be identified sufficiently by their chemical composition because the number of constituents is relatively large; the composition is, to a significant degree, unknown; and/or the variability of composition is relatively large or poorly predictable.

V

Vulnerable populations

A group of individuals within the Canadian population who, due to greater biological susceptibility or greater exposure, may be at an increased risk of experiencing adverse health effects from exposure to substances.