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T-4- 93 – Safety standards for fertilizers and supplements

1. Purpose

This document is a single source for all standards used by the CFIA to evaluate the safety of fertilizer and supplement products. It applies to products that require registration under the Fertilizers Act as well as those that are exempt from pre-market assessments. This document outlines:

2. Prohibitions and standards in the regulations

2.1 General prohibition

A person shall not manufacture, sell, import or export any fertilizer or supplement that contains any substance or mixture of substances that present a risk of harm to human, animal or plant health or the environment (except pests) when the fertilizer or supplement is used according to its directions for use or in an amount that is not in excess of the amount that is necessary to achieve its intended purposes.

2.2 Safety standards

When used in accordance with directions for use or in an amount that is not in excess of the amount that is necessary to achieve its intended purposes, a fertilizer or supplement must not contain:

2.3 List of materials

A fertilizer or supplement that is listed on the List of Materials shall meet the definition in that List that corresponds to that term. If the product is represented to contain a material whose term is set out in the List of Materials it must, in fact, contain that ingredient.

3. Upper limits and thresholds

3.1 Metals

3.1.1 Background

The metal standards are used to evaluate all products regulated under the Fertilizers Act for which metal concerns have been raised (e.g., recycled materials or materials with naturally elevated metal(s) levels). The standards apply to total (not extractable) metal content and are conservative to account for long term cumulative effects of metals on plant, animal and human health. They further account for metal concentrations in soils, and plant uptake factors such as soil acidity and soil cation exchange capacity. The standards are also protective of the effects of metals in worst-case application scenarios for hydroponics (soilless) applications.

The metals of concern include arsenic (As), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), mercury (Hg), molybdenum (Mo), nickel (Ni), lead (Pb), selenium (Se) and zinc (Zn).

3.1.2 Upper limits/thresholds

Metals limits are predicated on the maximum acceptable cumulative addition to soils over a 45 year time period. The cumulative application approach is intended to account for the persistence of metals in the environment which ultimately determines the level of contamination and long term impacts.

The maximum acceptable metal concentration in a product (in mg metal/kg product) is calculated for each metal using the CFIA standards for maximum acceptable addition to soil and the product's maximum recommended annual application rate. The formula is as follows:

1000000 mg kg × [ maximum acceptable cumulative metal addition to soil over 45 years ( kg metal / ha ) 45 years × annual application rate ( kg product / ha / yr ) ]

All fertilizers and supplements, including processed sewage, composts and other by-products are required to meet the standards for maximum acceptable cumulative metal additions to soil.

Certain metals such as copper (Cu), molybdenum (Mo) and zinc (Zn) are also essential plant nutrients. Products represented to contain (that is, guarantee) Cu, Mo and Zn that are used to treat a specific nutrient deficiency are not required to have an application rate specified on the label; rather the label states that the application rate is to be based on a soil or tissue test. In those instances, concentrations of the metal may exceed the metal standard (due to limited frequency of application) and the 95th percentile of the provincially recommended agronomic application rate is used in the calculations. These products must still meet the prescribed labelling standards including representation of the element as a plant nutrient, the associated guaranteed analysis and appropriate cautionary statements.

Table 1: CFIA fertilizer and supplement metals standards and examples of maximum acceptable metal concentrations based on annual application rates
Metal Maximum acceptable cumulative metal addition to soil over 45 years
(kg metal/ha)
Examples of a maximum acceptable concentration of a metal based on annual application rate
(mg metal/kg product)
4400 kg/ha per year 2000 kg/ha per year 500 kg/ha per year
Arsenic (As) 15 75 166 666
Cadmium (Cd) 4 20 44 177
Chromium (Cr) 210 1060 2333 9333
Cobalt (Co) 30 151 333 1333
Copper (Cu) 150 757 1666 6666
Mercury (Hg) 1 5 11 44
Molybdenum (Mo) 4 20 44 177
Nickel (Ni) 36 181 400 1600
Lead (Pb) 100 505 1111 4444
Selenium (Se) 2.8 14 31 124
Thallium (Tl)Table Note 1 1 5 11 44
Vanadium (V)Table Note 1 130 656 1444 5777
Zinc (Zn) 370 1868 4111 16444

Table Note

Table Note 1

Not all products require results of analysis for Thallium and Vanadium. These are an example of additional results that may be requested based on product or material type, on a case-by-case basis.

Return to table note 1  referrer

Note: the application rate and the metal concentration must be presented on the same basis (i.e. both dry weight or both as is).

Note: the Canadian Council of Ministers of the Environment (CCME), Bureau de normalisation du Québec (BNQ) and many provinces also have guidelines for metals in soils, or in sludge, compost, and other products that are land applied. We recommend that you contact your provincial or territorial government to obtain additional information.

Adding a guarantee for Selenium (Se) or Cobalt (Co) to a fertilizer makes the product a registrable fertilizer containing a supplement as these (Se and Co) are not essential nutrients for all plant species.

The above limits have been applied to hydroponics (soilless) products with an application rate conversion from ml/L or g/L to a per hectare unit.

A compliance verification tool – an excel spreadsheet that automates metal standard calculations, (for hydroponics products, select the use pattern: hydroponics – soilless media), is available upon request from It is intended to assist manufacturers and product proponents as well as CFIA inspectors in determining compliance of the final product with the standards. Compliance determination for growing media without directions for use

Growing media that contain fertilizers and/or supplements are exempt from registration under subsection 3.1(4) of the Fertilizers Regulations and, as such, are not required to have complete directions for use on the label. Without directions for use on a product label, there is no application rate that can be used to verify compliance with safety limits for heavy metals, dioxins and furans. To enable compliance verification with the safety standards, the CFIA uses a standard 45 year application rate of 2,000,000 kg/ha (annual application rate of 44,444.44 kg/ha).

The standard application rate was calculated with the following assumptions:

  1. Growing Media are used as a substrate to grow plants (that is to say, in pots or containers without soil mixing)
  2. The growing media are used once over 45 years as a starter
  3. There are 2,000,000 kg of soil in 1 hectare (ha) based on a soil depth of 15 cm and a soil density of approximately 1300 kg/m3

This approach is protective of human, plant, animal and environmental health and does not introduce any additional or stricter requirements (most growing media products currently in the marketplace are anticipated to be compliant). They also align with CCME Guidelines for Compost Quality when the difference between dry weight (CCME) and actual moisture content (CFIA) are factored in.

Metals Standards
Metal Maximum acceptable concentration in growing media without directions for use (mg metal/kg wet weight (as is) growing media) Category A Category B
Wet weight Dry weightTable Note 2 Maximum
concentration in a product
(mg/kg dry weight)
concentration in a
(mg/kg dry weight)
Arsenic (As) 7.5 18.75 13 75
Cadmium (Cd) 2 5 3 20
Chromium (Cr) 105 262.5 210 -
Cobalt (Co) 15 37.5 34 150
Copper (Cu) 75 187.5 400 -
Mercury (Hg) 0.5 1.25 0.8 5
Molybdenum (Mo) 2 5 5 20
Nickel (Ni) 18 45 62 180
Lead (Pb) 50 125 150 500
Selenium (Se) 1.4 3.5 2 14
Thallium (Tl) 0.5 1.25
Vanadium (V) 65 162.5
Zinc (Zn) 185 462.5 700 1850

Table Note

Table Note 2

Based on a 60% moisture content. CCME used 60% moisture content when comparing Category B standards to CFIA standards.

Return to table note 2  referrer

Dioxins and Furans Standards
Maximum acceptable PCDD/Fs concentration in growing media without directions for use (ng TEQ/kg growing media)
PCDD/Fs 2.6775

This compliance verification approach applies to a limited sub-set of growing media products that are regulated under the Fertilizers Act, but are not required to carry full directions for use on the product label. Growing media labelled with directions for use such as: "mix, blend or apply as top dressing" that claim to improve the physical condition of the soil, are regulated as supplements. Analogously, growing media that are represented as a source of plant nutrients are regulated as fertilizers. In those instances, product compliance is determined based on the directions for use on the label or the standard application rate for growing media (whichever one is higher). Most fertilizers and supplements require directions for use and, if marketed without them, are considered non-compliant with the labelling requirements and may be subject to enforcement action.

For ease of reference, the compliance calculator (available on request ) automatically uses the standard application rate and renders a compliance rating when you enter regulated growing media as the product type.

3.1.3 Results of analysis

To demonstrate compliance with the trace metals standards, proponents are required to provide results of analyses for the 11 metals of concern discussed above: As, Cd, Co, Cu, Cr, Hg, Mo, Ni, Pb, Se, and Zn. The number of metal analyses that are required at the time of new registration or re-registration, corresponds to the total number of batches/lots of product manufactured within a five (5) year interval preceding the submission of an application for a new or re-registration. This is depicted in Table 2. Analyses provided must be reflective of the batches manufactured over the five year period. For example, if five analyses are required, it is recommended to submit one analysis from each calendar year. Products generated by continuous process require 6 sets of analysis evenly spread over the five (5) year interval preceding submission.

Where results of requisite number of analyses are not available (e.g. because product is not yet being manufactured) please contact the Fertilizer Safety Section for guidance. These will be considered on a case-by-case basis.

Table 2: CFIA fertilizer requirements for metals analyses
# of Batches/Lots produced within the 5 years preceding the submission # of Sample analyses required
1 1
2 to 4 2
5 to 9 3
10 to 16 4
17 to 25 5
26+ Schedule to be provided by stakeholder and approved by the CFIA To be determined

3.2 Dioxins and Furans

3.2.1 Background

Polychlorinated dibenzo-p-dioxins (dioxins; PCDDs) and polychlorinated dibenzofurans (furans; PCDFs) are highly persistent environmental contaminants. They are found in all living organisms at very low levels and can bio-accumulate in food chains due to their lipophilic characteristics. The requirement for dioxin and furan analysis is dependent on the ingredients (and their sources) used in a product.

3.2.2 Upper limits/thresholds

The CFIA standard for maximum acceptable cumulative addition to soils of dioxins and furans is 5.355 mg TEQ/ha over 45 years (where TEQ = Toxic Equivalency Quotient). Like the CFIA metals standards, the application rate of a product is a crucial element in determining acceptable product dioxins/furans concentrations and the 45 year cumulative application approach is employed to account for environmental persistence and long-term impacts. Table 3 lists the congeners to be analyzed in determining total product dioxins and furans concentration.

Dioxins and Furans congeners for which results of analysis are required in determination of total product dioxins and furans concentration.

Chlorinated dibenzo-p-dioxins
Compound Toxic Equivalency Factors (TEF)
2,3,7,8-TCDD 1
1,2,3,7,8-PCDD 1
1,2,3,4,7,8-HCDD 0.1
1,2,3,6,7,8-HCDD 0.1
1,2,3,7,8,9-HCDD 0.1
1,2,3,4,6,7,8-HCDD 0.01
OCDD 0.0001
Chlorinated dibenzofurans
Compound Toxic Equivalency Factors (TEF)
2,3,7,8-TCDF 0.1
1,2,3,7,8-PCDF 0.05
2,3,4,7,8-PCDF 0.5
1,2,3,4,7,8-HCDF 0.1
1,2,3,6,7,8-HCDF 0.1
1,2,3,7,8,9-HCDF 0.1
2,3,4,6,7,8-HCDF 0.1
1,2,3,4,6,7,8-HCDF 0.01
1,2,3,4, 7,8,9-HCDF 0.01
OCDF 0.0001
Non-ortho substituted PCBs
Compound Toxic Equivalency Factors (TEF)
3,3',4,4'-PCB 0.0001
3,4,4',5-PCB 0.0003
3,3',4,4',5-PCB 0.1
3,3',4,4',5,5'-PCB 0.03
Mono-ortho substituted PCBs
Compound Toxic Equivalency Factors (TEF)
2,3,3',4,4'-PCB 0.00003
2,3,4,4',5-PCB 0.00003
2,3',4,4',5-PCB 0.00003
2',3,4,4',5-PCB 0.00003
2,3,3',4,4',5-PCB 0.00003
2,3,3',4,4',5'-PCB 0.00003
2,3',4,4',5,5'-PCB 0.00003
2,3,3',4,4',5,5'-PCB 0.00003

The maximum acceptable product dioxins/furans concentration (in ng TEQ/kg product) is calculated using the CFIA standard for maximum acceptable 45-year cumulative dioxins/furans addition to soil (5.355 mg TEQ/ha) and the product's maximum recommended annual application rate as follows:

1000000 ng mg × [ 5.335 mg TEQ / ha 45 years × annual application rate ( kg product / ha / yr ) ]

A maximum product concentration of 100 ng TEQ/kg product is considered protective for workers and bystanders. Table 4 shows the dioxin/furan acceptable concentrations for products at different application rates.

Table 4 – CFIA Dioxin and Furan standards and examples of maximum acceptable PCDD/Fs concentrations in based on annual application rates
  Maximum acceptable cumulative PCDD/Fs additions to soil over 45 Years
(mg TEQ/ha)
Examples of maximum acceptable PCDD/Fs concentration based on annual application rates
(ng TEQ/kg product)
4400 kg/ha – yr 2000 kg/ha – yr
PCDD/Fs 5.355 27 59.5

A compliance verification tool mentioned above (below Table 1) is available from upon request. The calculator includes functionality for Persistent Organic Pollutants limits.

3.3 Indicator organisms

3.3.1 Background

Monitoring for microbial contaminants in fertilizers and supplements must be carried out to provide information on the adequacy of pathogen-reducing processing or sterilization steps and the microbial condition of the final product. Given their widespread presence in the environment, Salmonella and Faecal coliforms are used as indicators of microbial contamination and effectiveness of treatment process. This practice is aligned with the United States Environmental Protection Agency's Part 503 Rule. The requirement for indicator organism testing allows for detection of any re-growth of bacteria and substantiates the effectiveness of pathogen reduction processes in place.

3.3.2 Upper limits/thresholds

Table 5: Maximum acceptable level of indicator organisms in fertilizers and supplements
Indicator organism Level Minimum detection limit
Salmonella Not Detectable less than 1 CFU (Colony Forming Unit) / 25 grams
Faecal Coliforms 1000 MPN (Most Probable Number) / gram solid less than 2 CFU / gram

Tests for indicator organisms are required to meet the minimum detection limits specified in Table 5.

A compliance verification tool mentioned above is available from upon request. The calculator includes functionality for indicator organism limits.

The FSS reserves the right to require analyses for additional pathogenic organisms depending on the nature of the product, as assessed on a case-by-case basis.

4. Tolerances for fertilizers guaranteeing micronutrients

4.1 Background

Micronutrients (Boron (B), Chlorine (Cl), Copper (Cu), Iron (Fe), Manganese (Mn), Molybdenum (Mo) and Zinc(Zn)) are essential plant nutrients that are required in small amounts, and their deficiency can negatively impact plant growth and crop yield. However, when applied in excess, micronutrients can have adverse health effects on animals, plants and the environment. Micronutrients can also persist and accumulate in soil (leading to environmental impacts) or in hydroponic growing media. This accumulation increases the risks of uptake by crops, resulting in potential feed and food contamination, adverse animal and human health effects and long term environmental impacts.

To mitigate the risks of over-application and promote safe use, fertilizers represented to contain micronutrients (guaranteeing micronutrients) either alone or in combination with other nutrients are subject to registration and pre-market assessment prior to importation and sale in Canada irrespective of the end use pattern (see registration triggers for fertilizers and supplements and T-4-129 - Requirements for micronutrient fertilizers ). Upper tolerances for micronutrient guarantees have been established to enable compliance verification both at the premarket assessment stage as well as marketplace monitoring and enforcement. The tolerances are based on analytical variability associated with product analysis and sampling error as well as attainability based on modern manufacturing practices.

4.2 Tolerances

For a given guarantee (left column), the permissible exceedance (numerical value) is added to the guarantee yielding the maximum allowable content (right column).

Table 6: Upper tolerances for fertilizers represented to contain micronutrients
Guarantee range Permissible guarantee exceedance
< 0.0033 0.0013
0.0033-0.0099 0.0040
0.010-0.032 0.010
0.033-0.099 0.031
0.10-0.32 0.077
0.33-0.99 0.23
1.0-3.2 0.60
3.3-9.99 1.0
≥ 10 10% of Guarantee

Note: tolerances vary depending on the range of the micronutrient guaranteed – the tolerance is greater in the low range guarantee and smaller if the concentration in the product is higher. For example, a 0.24% Cu guarantee has a permissible exceedance of 0.077, for a maximum acceptable Cu content of 0.317%. On the upper end 11% Cu guarantee has a permissible exceedance of 10% of the guarantee, in this case 1.1%, for a maximum acceptable Cu content of 12.1%.

4.3 Results of analysis requirement

Proponents of micronutrient fertilizers are also required to provide results of analysis for guaranteed micronutrients in addition to the results of analysis for the reportable metals (As, Cd, Cr, Co, Cu, Hg, Mo, Ni, Pb, Se, Zn) at the time of registration and re-registration to ensure that the actual content of the nutrient in the product does not exceed the guarantee by an amount that is higher than the allowable tolerance. The number of analyses required will be based on the number of batches produced as per the current policy – for details please refer to Table 2 above.

5. Precautionary statement requirements

As per the Fertilizers Regulations, a statement setting out any precaution that is necessary to mitigate a risk of harm to human, animal or plant health or the environment (except pests) may be required on the label/package of any regulated fertilizer or supplement product. The Regulations do not specify the exact wording of the precautionary statement required and these are determined on case-by-case basis depending on the ingredients in the product, its risk profile and intended use pattern.

Note: given that Boron is a Category 1B reproductive toxicant, all fertilizers with Boron (Boric acid and its salts) content greater than 0.3% of the final product require the following statement on the product label: "May damage fertility or the unborn child".

Note: fertilizers or supplements that contain or may contain Health Canada identified priority allergen(s) have the potential to induce skin and respiratory allergic responses in users. Priority allergens include eggs, milk, mustard, peanuts, crustaceans and molluscs, fish, sesame seeds, soy, sulphites, tree nuts, wheat or triticale. If a fertilizer or supplement contains or may contain one or more of these ingredients, a cautionary statement similar to the following must be present on the product label: "Caution: This product contains/may contain (list all allergens). Adverse reactions may occur in sensitive persons. If skin contact occurs, wash with soap and water. Wear dust mask and protective gloves. If allergic reaction occurs, seek medical attention".

In addition, the Regulations require that product proponents and importers disclose the list of ingredients that present a risk of harm to the health of ANY human or animal that do not appear on the label to the requester in English or in French.

6. Methods

To be accepted, a method of analysis used to test a fertilizer or supplement must be specific for the purpose of the analysis, selective, reliable, and accurate for the active ingredient in the formulated product.

7. Globally harmonized system of classification and labelling of chemicals

In order to facilitate international trade and enhance human and environmental health protection, the global regulatory community has developed a standardized Globally Harmonized System of Classification and Labelling of Chemicals (GHS) to which Canada is a signatory. GHS is administered by Health Canada under the Hazardous Products Regulations. Suppliers, importers and producers are responsible for classifying hazardous products and preparing labels and safety data sheets.

For more information go to: GHS: OSH Answers Fact Sheets and WHMIS Transition.

8. Contact information

Fertilizer Safety Section
Canadian Food Inspection Agency
Telephone: 1-855-212-7659

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