Regulation of Liming Materials offered for sale in, and/or imported into, Canada

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Governing Legislation

The Fertilizers Act and Regulations is the federal legislation governing the sale and importation of liming materials in Canada. This legislation is administered by the Fertilizer Program of the Canadian Food Inspection Agency (CFIA). Liming materials are classified as supplements under the Fertilizers Act and Regulations. The manufacture, proper use and safe disposal of these products are controlled by provincial and municipal rules and regulations. The CFIA works together with provinces and municipalities to ensure that all fertilizers and supplements meet the highest standards for safety and efficacy.

Legislative Requirements

The Fertilizers Act and Regulations require that all liming material products be effective when used according to labelled directions, and safe for humans, plants, animals, and the environment. They must also be properly labelled. Section 3.1 (3) (c) of the Fertilizers Regulations provides for the exemption from registration of liming material products. As such, products sold only for the correction of soil acidity (or alkalinity) do not require a pre-market assessment and registration. However, manufacturers of non-registerable products are encouraged (although it is not mandatory) to seek a letter of no-objection to the sale of the product in Canada from the Fertilizer Section and Fertilizer Safety Office of the CFIA to ensure that their product meets the requirements. If the product is made from waste materials, a list of the submission requirements can be found in trade memorandum T-4-112: Information Required for the Assessment of By-products and Other "Waste" Materials Sold as Fertilizers or Supplements.


As with all fertilizers and supplements, liming materials must be safe for humans, plants, animals, and the environment. The CFIA routinely monitors liming material products for heavy metal contamination. All liming products must ensure that they do not exceed the following heavy metals standards, which are based on application of the product over a 45 year period.

Table 1: Maximum acceptable cumulative metal additions to soil
Metal Maximum allowable application to soil
(kg/ha/45 years)
Arsenic 15
Cadmium 4
Chromium 210
Cobalt 30
Copper 150
Mercury 1
Molybdenum 4
Nickel 36
Lead 100
Selenium 2.8
Zinc 370

As with the metal standards, the current standard for dioxins and furans is linked to the application rate of a product and the maximum acceptable cumulative addition to soil. The applicability of dioxin and furan analysis is dependent on the ingredients used in the product. Currently, the CFIA uses an interim maximum acceptable cumulative addition to soil standard for polychlorinated dibenzo-p-dioxins (dioxins; PCDD) and polychlorinated dibenzofurans (furans; PCDF) of 5.355 mg TEQ/ha over 45 years (where TEQ = Toxic Equivalency Quotient).

Depending on the ingredients used to manufacture the liming material, pathogen monitoring samples may also be taken to analyze for the presence of Salmonella and faecal coliforms. Salmonella bacteria present a human health risk primarily to those consuming food crops. They have the ability to re-grow from very low levels to very significant levels which is why a standard of non-detectable is used. Because of their resistance to heat treatment relative to other organisms, they may be used as indicators of the possible presence of other biological contaminants of concern.


All liming materials must be efficacious for their intended purpose. That is to say, when the product is used according to the labeled directions, or at the direction of a trained agricultural specialist, there must be a significant increase in soil ph.


The Fertilizers Regulations sets out the required information that must be present on the label of a packaged liming material, or on the shipping bill (or other document accompanying the shipment) of a liming material sold in bulk. The following is a brief overview of those requirements:

Product name

The product name must adequately convey the use of the product while not containing any misleading information or mark. The product name can not contain reference to any type(s) of soil. For packaged products the product name must appear on the main panel of the product label. Brand names can be used, but are not required. No misleading information or mark, as well as soil type(s) are allowed in the brand name.

Guaranteed Minimum Analysis

This section on the label/shipping bill must be entitled "Guaranteed Minimum Analysis".

Calcium and magnesium guarantees are required for liming materials containing calcium and magnesium compounds capable of neutralizing soil acidity. If a product's acid neutralizing capability does not come from calcium or magnesium compounds, guarantees for calcium and magnesium should not be made. When guaranteed, the amount of calcium and magnesium must be the minimum amount of each element expected to be found through chemical analysis of the product, and expressed as a percent of the total weight of the product. Guarantees for calcium and magnesium must be expressed as:

Calcium (Ca)…XX% Magnesium (Mg)…XX%

For Ca and/or Mg guarantees of less than 1%, analytical result deficiencies must be within 25% of the guaranteed amount or the product is considered to be non-compliant. For Ca and/or Mg guarantees of more than 1%, analytical result deficiencies must be within 0.15% of the liming material plus 10% of the guaranteed amount up to a maximum of 1.0% of the liming material, or the product is considered to be non-compliant.

The product's neutralizing value, as a percentage of the neutralizing value of pure calcium carbonate (100), must be guaranteed. The neutralizing value guarantee, sometimes referred to as calcium carbonate equivalence, must be expressed as:

Neutralizing value (CaCO3 equivalent)…XX%

A maximum deficiency of 1% of the liming material is allowed for neutralizing value guarantees.

The amount of product that can pass through 10 and 100 mesh Tyler screens must also be guaranteed. Pelletized products can display the fineness of the material prior to pelletization in the Guaranteed Minimum Analysis section of the label. However, a statement indicating the particle size prior to pelletization should be included on the product label outside of the Guaranteed Minimum Analysis section (see example label). The fineness of the liming material must be expressed as:


  • Passes 10 mesh Tyler screen…XX%
  • Passes 100 mesh Tyler screen…XX%

A maximum deficiency of 1% of the liming material is allowed for each mesh size guarantee.

Directions for Use

Directions for use must be present on the label/shipping bill. These directions can either convey specific application rates for specific situations or can direct the user to seek the advice of an agricultural professional. If specific directions for use are stated on the label, the starting pH, soil type (sand, silt, clay), as well as rate, frequency, and timing of application should be included. Unless otherwise stated, it is assumed that specific directions for use will target obtaining a pH range of between 6 and 6.5. If an alternate pH is targeted (crops with a higher or lower optimal soil pH), this should be stated on the label. In all instances a statement indicating that the product should be used on the basis of soil pH test, should be included on the label.

Net Weight

The net weight must be stated in metric units. Imperial units may follow the metric units in brackets. For packaged products the net weight must appear on the main panel of the product label. Net weight = 20 kg (44 lbs).

Responsible packager's name and address

The label/shipping bill must state the name and complete mailing address (street/P.O. Box, city, province/state, postal/zip code) of the person who packaged/manufactured the liming material. For packaged products the responsible packager's name and address must be stated on the main panel of the product label.

Lot number

Lot number is defined as any combination of letters and/or numbers by which a fertilizer or supplement can be identified and traced. A lot number should be assigned to unique batches of liming material product derived from a single production run, mining date/location, delivery date, packaging date, etc. Each lot or batch should be assigned on the belief that all product in the lot or batch is of similar chemical and physical characteristics. The lot number must be present on the label or shipping bill.


All information printed on a label or shipping bill must be in either English or French or entirely in both English and French.

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