Ministère de l'Environnement
et de la Lutte contre les changements climatiques

About Pesticides

Updated: February 2021

What is a pesticide?

Grouping of pesticides

What is a pesticide?

Definition and composition of a pesticide

Usually, a pesticide is a product designed to destroy organisms deemed to be undesirable or noxious. End-use products contain one or several active ingredients and formulants.

Active ingredient: component of a product to which is linked the pesticide’s effect. The common name of the active ingredient appears on the label product under the heading “guarantee”.

Formulant: any component of a pesticide that is added intentionally and that is not an active ingredient. It improves the physical characteristics of a pesticide (e.g., sprayability, solubility, spreadability or stability). Contrary to active ingredients, formulants are not mentioned on the product label. Kerosene, ethanol, gelatin and soybean oil are formulants. To learn more about these, please consult the List of Formulants used in pesticides in Canada.

A pesticide is designated by its common name, chemical name or commercial name.

  • The common name refers to the active ingredient. For example, Roundup, a commercially available product, contains an active ingredient, known under the common name "glyphosate".
  • The chemical name designates the active ingredient chemical structure name. For example, the chemical name of glyphosate is "N-(phosphonomethyl)glycine".
  • The commercial name is the name given by the manufacturer. For example, glyphosate is sold under the name "Roundup".

Legal definitions

In addition to their usual definition, pesticides also have a legal definition. These products are designated by two terms: "pest control products" according to the legislation at federal level, and "pesticides" at the provincial level.

At the federal level

At the federal level, the Pest Control Products Act includes the definition of two terms, namely:

"control product" which means a product, an organism or a substance, including a product, an organism or a substance derived through biotechnology, that consists of its active ingredient, formulants and contaminants, and that is manufactured, represented, distributed or used as a means for directly or indirectly controlling, destroying, attracting or repelling a pest or for mitigating or preventing its injurious, noxious or troublesome effects.

"pest" an animal, a plant or other organism that is injurious, noxious or troublesome, whether directly or indirectly, and an injurious, noxious or troublesome condition or organic function of an animal, a plant or other organism.

Any pest control product imported, sold or used in Canada must be registered by the Pest Management Regulatory Agency (PMRA) of Health Canada. By the end of its registration process and before it is marketed, each product is given a sequential registration number, which must appear on its label. Registration process is summed up in the document The Regulation of Pesticides in Canada.

In Canada, 7900 commercial products are registered. You may consult their label contents by using the Search Product Label tool offered by the PMRA. Research work can be done in using the active ingredient name, trade name or product registration number.

It should also be noted that the PMRA combines biopesticides into three main categories: microbial agents, semiochemicals and non-conventional products.

At the provincial level

In Québec, under the Pesticides Act, the word "pesticide" means any substance, matter or microorganism intended to directly or indirectly control, destroy, mitigate, attract or repel any organism that is injurious to or noxious or troublesome for humans, animal life, vegetation, crops or any other object, or intended for use as a plant growth regulator, except a vaccine or a medication other than a topical medication for external use on animals.

Québec legislation applies to pesticides registered by the PMRA. Moreover, some pest control products are not subject to Québec legislation, namely:

  • algicides or bactericides for swimming pools and aquariums or for the treatment of drinking water
  • air cleaners
  • disinfectants
  • detergent additives
  • mechanical or physical mechanisms, such as apparatuses to attract and destroy flying insects, ionizers for algae control in swimming pools and spas, devices to repel pests by causing physical discomfort by means of sound, touch or electromagnetic radiation

Although 4,500 products and 600 active ingredients meet the Québec pesticide definition, only 1,200 products and 370 active ingredients are actually sold within the province’s territory (Account of pesticide sales in Québec).

Pesticide grouping

Usually, pesticides are named according to their grouping which takes into account the product’s target, its origin and chemical structure, how it is marketed as well as the target site and its mode of action.

A pesticide can be grouped according to the following criteria:

  • category of use
  • origin
  • chemical group
  • type of formulation
  • type of activity
  • site or mode of action

Category of use

Most of the pesticides can be grouped according to their target. Note that the suffix –cide means "to kill."

Category of use Targets Examples of targets
Avicide Birds
  • Pigeon
Fungicide Microscopic fungi causing plant diseases
  • Diplocarpon rosae causing rose black spot
  • Pucciniastrum epilobii causing fir needle rust
  • Venturia inaequalis causing apple scab
Herbicide Herbaceous plants
  • Lamb’s quarter
  • Quack grass
  • Poison ivy
  • Plantain
Insecticide Insects
  • Cockroach
  • Colorado potato beetle
  • Hairy chinch bug
  • Eastern spruce budworm
Miticide Mite
  • House dust mite
  • Maple bladdergall mite
  • Two-spotted spider mite
Molluscicide Terrestrial mollusks
  • Snail
  • Slug
Nematicide Nematodes causing plant diseases
  • Meloidogyne hapla causing carrot root knot
Phytocide Herbaceous and woody
plant species
  • Large-scale tree
Piscicide Fish
  • White sucker
Rodenticide Rodents
  • Rat
  • Mouse

Other pesticides, which name includes –cide as a suffix, such as "ovicide", "larvicide" or "adulticide", designate substances specifically intended for destroying insects at the egg, larvae or adult stage. Also, some pesticides’ names end with the suffix –fuge which means "to repel", as in the word "insectifuge", which means "insect repellent" or "avifuge", which means "bird repellent".

Other categories of use exist, which are:

  • animal repellent;
  • antifouling paint;
  • pheromone;
  • plant growth regulator;
  • pruning paint;
  • topical medication intended for animals;
  • wood preservative.


Usually pesticides are grouped in two categories: organic and inorganic pesticides. Organic pesticides contain carbon, while inorganic pesticides contain carbon which can be found only under the form of carbonate or cyanide. These pesticides are derivatives made from arsenic, mercury, fluorine, sulphur and copper, as well as derivatives made from cyanide.

Organic pesticides can be divided into three groups: synthetic pesticides (developed in laboratories and manufactured), natural pesticides (from animal, microbial or vegetal origin) and microorganisms. Inorganic pesticides are mostly derived from minerals.

Chemical group

A chemical group is formed with pesticides which have a similar chemical structure.

For example, the chemical structure of atrazine shown in the following diagrams allows putting this pesticide in the triazines and tetrazines group.

Atrazine - 2D

Atrazine - 3D

Chemical groups established by the Ministère are described in the Guide for classification of pesticides by chemical group.

Type of formulation

Pesticides are available in different formulations and can be obtained under solid, liquid or gaseous form.

Some pesticides are marketed as ready-to-use products, in other words they do not need any special preparation before application. On the other hand, others do need to be prepared. For example, some products may need to be mixed in exact proportions with water before application. This mixture is usually called a "spray mixture." In this case, preparation involves diluting a concentrated product.

Formulant examples Ready to use or to be mixed
Solid form
Bait Ready to use
Powder Ready to use
Wettable powder To be mixed
Liquid form
Spray Ready to use
Emulsifiable concentrate To be mixed
Solution To be mixed
Gaseous form
Fumigant Ready to use

Type of activity

Herbicides, fungicides and insecticides can be designated according to their action on undesirable organisms.


Contact Is active only on plant parts that are covered with it.
Systemic Absorbed by the plant, this herbicide moves inside it.
Selective Herbicide that destroys certain plants among those being under treatment.
Non-selective Controls all of the treated plants.
Residual Residual A product that breaks down slowly and controls plants over a long time.
Non-residual Action ceases quickly after application and controls plants over a short time.
Protective Protects the plant prior the disease infection by preventing the latter to develop.
Eradicant Fights a disease which has already developed.
Contact Acts when insect is in contact with the product.
Inhalation Acts when insect inhales the product.
Ingestion Acts when insect feeds on product.

Site or mode of action

Pesticides can be grouped according to the site or mode of action on the undesirable organism on which they act. Several sites or modes of action are known for herbicides, insecticides as well as fungicides. Here are some examples:

  • Insecticides control insects:
    • by interfering on their nervous system, or

    • by preventing moulting from the larval to the adult stage.
  • Herbicides control plants:
    • by inhibiting photosynthesis, or
    • by reproducing effects of plant growth regulators which they produce naturally.
  • Fungicides control fungi:
    • by inhibiting amino acid synthesis, or

    • by interfering with cell division.

The list of pesticides groups constituted according the site or mode of action is available in the federal registration directive Voluntary Pesticide Resistance-Management Labelling Based on Target Site/Mode of Action.


Pheromone: A semiochemical produced by an individual of a species that evokes a behavioural response in individuals of the same species.

Registration: An administrative act authorizing the sale, importation or use of pest control products in Canada.

Semiochemical: A message-bearing substance produced by a plant or animal, or a functionally identical synthetic analogue of that substance, which evokes a behavioural response in individuals of the same or other species.

Topical medication intended for animals: External use product which acts where it is applied on the animal. These medications relate mainly to two product ranges: those intended for house pets (for example, shampoo, lotion, powder, anti-flea collars and tags for dogs and cats) and those intended for livestock and cattle (for example, insecticide ear tags for cattle).

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