Guidance on efficacy requirements for biocides: Hard-surface disinfection and sanitization

On this page

• Types of claims
• General claims
• Hard-surface disinfectant claims
  • Limited, general (broad-spectrum) and hospital or health care disinfection
  • Mycobacteria disinfection
  • Fungal disinfection
  • Virus disinfection
  • Spore and sterilant
• Non-food contact and food contact sanitizers on hard surfaces
  • Non-food contact hard non-porous surface sanitizer
  • Food contact surface sanitizer
• Residual disinfection and sanitization
  • Residual sanitization claims
  • Residual disinfection claims

Types of claims

In general, there are 2 different types of biocidal claims:

• specific claims
  • direct claims
  • indirect claims
• general claims

Direct claims show a causal relationship. These claims require efficacy information that demonstrates your biocide is effective against specific micro-organisms. An example of a direct claim would be "This biocide kills SARS-CoV-2 (the virus that causes COVID-19)".

Indirect claims show a relationship and are only accepted during a pandemic declared by the World Health Organization (WHO). These claims allow you to provide Health Canada with efficacy testing using another micro-organism that is similar or harder to kill than the proposed micro-organism. An example of an indirect claim would be "This biocide kills rhinovirus type 16 and is likely to kill SARS-CoV-2 (the virus that causes COVID-19)".

If your biocide qualifies for both a direct and an indirect claim, you should only include the direct claim on the label.

Learn more about claims against emerging pathogens.

General claims

Before proposing a general claim for your biocide, you should first demonstrate if your biocide is a general (broad-spectrum) biocide or a hospital or health care disinfectant. This applies to claims to destroy (kill), inactivate or reduce or control the number of:

• germs
• viruses
• mycobacteria
• specific bacterial spores
• fungi, mould and mildew
• other non-spore forming bacteria
  • such as Escherichia coli

To propose a specific non-food contact surface sanitization claim, you should demonstrate that your biocide is a general non-food contact surface sanitizer. The same applies for specific food contact surface sanitization claims.

Studies to support your biocide application may be electronically signed by laboratories. This includes efficacy reports containing good laboratory practice (GLP) statements.

Hard-surface disinfectant claims

Disinfectants can destroy or irreversibly inactivate pathogenic (disease-causing) and potentially pathogenic (opportunistic) micro-organisms, but not necessarily bacterial spores, on hard surfaces. This is because of the antimicrobial action of the active ingredients.

Hard-surface disinfectants against bacteria should show they are effective 10 minutes after application or sooner.

Limited, general (broad-spectrum) and hospital or health care disinfection

For limited, general (broad-spectrum) and hospital or health care disinfectant claims, we require:

• 3 samples of the biocide representing 3 separate batches per representative test organism for the bactericide
• 60 inoculated carriers per batch per bacterium

The testing requirements for limited, general (broad-spectrum) and hospital or health care disinfectants are listed in Table 3.

Use the appropriate test method for testing against the following core bacteria for disinfection claims (for example, AOAC use-dilution methods for liquid biocides, AOAC 961.02 for spray biocides and modified AOAC 961.02 or ASTM E2362 for towelette biocides):

• Staphylococcus aureus
• Pseudomonas aeruginosa
• Salmonella enterica

You should test each of the 3 batches for Pseudomonas aeruginosa and Staphylococcus aureus on different days when using AOAC use-dilution methods.

Claims against bacteria allow you to label your biocide as a "bactericide" and "bactericidal". You must provide efficacy data to show different levels of efficacy for your biocide.

Mycobacteria disinfection

You will need efficacy data against a the representative Mycobacterium species to claim your biocide as a:

• mycobactericide
• mycobactericidal

A representative species could be Mycobacterium bovis BCG (ATCC 35473) or Mycobacterium terrae (ATCC 15755). Choosing the appropriate Mycobacterium species depends on the test method being used (for example, M. terrae has only been validated with certain test methods, such as the ASTM 2197 quantitative carrier method and the OECD quantitative method).

To make specific claims against certain mycobacteria, you must provide supporting efficacy data.

Only include specific claims (for example, effective against or kills Mycobacterium fortuitum) on your label if you:

• do not have efficacy data to support your biocide as a "mycobactericide" or "mycobactericidal" biocide
• have efficacy data to support the specific claim

If you have quaternary ammonium compounds as the sole active ingredient in your biocide, you should perform verification testing to confirm the mycobactericidal label claim. To do so, you must test 1 of the original biocide lots using the same test procedures and under the same conditions. Testing must be done in either:

• a different laboratory than the original one
• the same laboratory using different laboratory personnel
  • for example, different study director, technical staff and quality assurance (QA) auditor

Fungal disinfection

To make claims against fungi for your biocide, you must conduct fungicidal testing using fungal conidia (spores). You can only label your biocide as a fungicide or fungicidal if your efficacy testing is against Trichophyton interdigitale (formerly Trichophyton mentagrophytes) (ATCC 9533).

If you want to make specific claims against certain fungi, you must provide supporting efficacy data. If you do not have efficacy data to support a general fungicide claim, you may indicate a specific fungus claim on your label.

Virus disinfection

To have claims against viruses on your biocide label, you must show that your biocide is either a:

• virucide
  • may include claims against specific viruses
• broad-spectrum virucide

For broad-spectrum virucide claims, you must:

• test using 2 samples of the biocide representing 2 separately compounded batches per virus
• test on 1 inoculated carrier or surface per batch per virus (except when using surrogate viruses)
• test in quadruplicates at each dilution level

For all virus claims, you should use the ASTM E1053 test method with:

• an assay to detect the presence of remaining viable virus after treating the virus with the biocide, using the appropriate virological technique, such as:
  • cytopathic effect
  • fluorescent antibody
  • plaque count
• 4 determinants per dilution in the assay system in the:
  • virus recovery (control carrier counts)
  • cytotoxicity control
  • neutralization controls
  • treated carriers (test for disinfectant activity)

Note: For a modified ASTM E1053 method, use 1 towelette to wipe 1 test carrier (the carrier is large and the folded towelette is small). We recommend that you either:

• treat carriers in 2 parallel sections using the same towelette or
• use the wiping technique in ASTM E3363 for viral testing

Use an appropriate statistical method to calculate the 50% infectious dose (ID50) for each assay. Examples of appropriate methods include:

• Reed and Munch
• Most Probable Number
• Spearman-Karber

The hardest-to-kill virus on the label should be tested at or below the LCL. This is any small and non-enveloped virus that is indicated on the label, if present (for example, feline calicivirus, rhinovirus).

All easier-to-kill viruses can be tested at or below the nominal concentration (NCL). If there are no small non-enveloped viruses on the label, then testing should be conducted on 1 of the large non-enveloped viruses on the label (for example, adenovirus type 5, rotavirus).

If the biocide indicates claims only against enveloped viruses, then testing should be conducted at the LCL against any 1 of the enveloped viruses (for example, SARS-CoV-2).

Surrogate efficacy

You may use the following surrogate viruses to generate efficacy data for some virucide claims:

• duck hepatitis B virus (DHBV) for hepatitis B virus (HBV)
• bovine viral diarrhoea virus (BVDV) for hepatitis C virus (HCV)
• feline calicivirus for human norovirus

Note: Testing against 2 tests carriers per dilution in the assay system is acceptable for cytotoxicity and neutralization controls.

Spore and sterilant

You need efficacy testing against viable spore form (not vegetative cells) for all spore claims. If you want to label your biocide as a sporicide, sporicidal biocide or sterilant, you must have efficacy data using AOAC 966.04 against both:

• Bacillus spizizenii (ATCC 19659) (formerly known as Bacillus subtilis spizizenii), with spores generated using method 1 of the AOAC 966.04 in cooked meat medium treated with MnSO₄ for spore generation and inoculation of silk suture loops and using method 2 of the AOAC 966.04 in nutrient agar treated with MnSO₄ for spore generation and inoculation of porcelain penicylinders
• Clostridium sporogenes (ATCC 3584), with spores generated using method 1 of the AOAC 966.04 in cooked meat medium treated with MnSO₄ for spore generation and inoculation of porcelain penicylinders and silk suture loops

Contact us before you submit an application to find out the acceptable data requirements to support your claims.

For all sterilant and sporicide claims, use AOAC 966.04 with:

• all tested carriers being negative for growth at the proposed contact time (unless otherwise prescribed in the test method)
• a mean control count of 1 x 10⁵ to 1 x 10⁶ spores per carrier
• a level of acid resistance outlined in the test
• a confirmed neutralization using growth media and incubation conditions for each microbe according to method 2 (section C, subsection h)
• verification testing using 1 batch showing all tested carriers are negative for growth at the proposed contact time

If you want to make specific claims against specific bacterial spores, you must provide supporting efficacy data. You only need to include a specific claim (for example, "inactivates spores of Clostridioides difficile" or "kills spores of Clostridioides difficile) on your label if you:

• have efficacy data to support a specific claim
• do not have the efficacy data to support your biocide as a sporicide or sporicidal biocide

For surface-specific claims against additional bacterial spores (for example, Clostridioides difficile, Bacillus anthracis, Bacillus cereus, Geobacillus stearothermophilus), we require:

• evidence your biocide is a sporicide
• 2 LCL samples of the biocide, representing 2 separately compounded batches per bacterium
• 30 inoculated carriers of 1 type (stainless steel penicylinders, porcelain penicylinders or silk suture loops, for example) per batch per additional bacterial spore
  • for example: 1 carrier type per additional bacterial spore x 30 carriers per type = 60 carriers per type per batch

If there are no general sporicide or sterilant claims, you do not need to conduct verification testing when testing only against specific bacterial spores, such as:

• Bacillus cereus (ATCC 14579)
• Bacillus anthracis (ATCC 14578)
• Clostridioides difficile (ATCC 43598)
• Geobacillus stearothermophilus (ATCC 12980)

Claims supported by only Clostridioides difficile

For Clostridioides difficile (ATCC 43598) claims without a sporicide claim:

• a carrier control count of 1.0 x 10⁶ to 1.0 x 10⁷ spores per carrier
• a mean 6 log₁₀ reduction based on recoverable spores within proposed contact time for all carriers
• 10 inoculated hard non-porous carriers per batch
• 3 LCL samples of the biocide representing 3 separately compounded batches:
  • ASTM E3218 using:
• AISI Type 304 stainless steel carriers
• 3 independent tests (for example, 1 batch tested per day)
• Three-part soil load as specified in ASTM E3218 or at least 5% organic soil if using an alternative test method

Non-food contact and food contact sanitizers on hard surfaces

Sanitizers significantly reduce the number of microbes on a non-living and non-liquid surface due to the antimicrobial action of the active ingredients. They do not destroy or eliminate all micro-organisms.

Non-food contact hard non-porous surface sanitizer

You should use vegetative bacteria for your tests to demonstrate your biocide is a non-food contact surface sanitizer. Once the biocide is demonstrated to be a non-food contact surface sanitizer, you can make additional specific bacteria non-food contact surface sanitization claims on your biocide's label (for example, Escherichia coli).

To qualify to add the claim "non-food contact surface sanitizer" to the label, you must provide efficacy data against the following core bacteria:

• Staphylococcus aureus (ATCC 6538) and Klebsiella pneumoniae (ATCC 4352) or
• Staphylococcus aureus (ATCC 6538) and Klebsiella aerogenes (ATCC 13048)

To add non-food contact surface sanitization claims against viruses on the biocide label, you should refer to most recent version of the US EPA Interim Guidance for the Evaluation of Products for Claims Against Viruses.

Food contact surface sanitizer

To claim your biocide as a food contact surface sanitizer, you must provide efficacy data that relates to the chemical nature of your biocide (refer to Table 13). Once the biocide is demonstrated to be a food contact surface sanitizer, you may make additional specific bacteria food contact surface sanitization claims on your biocide label.

To qualify to add the claim "food contact surface sanitizer" to the label, you must provide efficacy data against the following core bacteria:

• For non-halide biocides: Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 11229)
• For halide biocides: Staphylococcus aureus (ATCC 6538) or Salmonella enterica (ATCC 6539)
• For towelette biocides: Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 11229)

To add food contact surface sanitization claims against viruses on the biocide label, you should refer to the most recent version of the US EPA Interim Guidance for the Evaluation of Products for Claims Against Viruses.

Use on alternative hard porous surfaces

If your biocide is for use on other types of hard porous surfaces, such as wood, concrete or rubber, you should:

• indicate the hard porous material (as a carrier) on the test protocol for the existing standard method
• develop control data (for example, dried carrier microbial count neutralization confirmation, sterility controls)

Refer to the US EPA's 810 product performance test guidelines for general efficacy and labelling considerations for products with sanitization or disinfection claims on alternative hard porous surfaces.

Residual disinfection and sanitization

Residual sanitization claims

For residual self-sanitizing claims (under 24 hours), you should test your biocide to confirm it continues to sanitize surfaces despite surface re-inoculation and abrasion. Depending on the sanitization claim, we recommend that you refer to US EPA's:

• 810.2300 and 810.2400 product performance test guidelines for general efficacy and labelling considerations for products with residual self-sanitizer efficacy or
• Protocol 01-1A for supporting residual self-sanitizing efficacy claims of dried chemical residues on hard, non-food contact surfaces

Residual disinfection claims

Testing for bacteria and viruses should be conducted at LCL for 2 separately compounded batches. If your biocide has virucidal claims, residual disinfection data are also required against the hardest-to-kill virus indicated on the label.

To make general residual bactericidal claims, you must show your biocide is effective against both:

• Staphylococcus aureus (ATCC 6538) and
• Pseudomonas aeruginosa (ATCC 15442)

For residual self-disinfecting claims and efficacy claims of dried chemical residues on hard, non-food contact surfaces, consult:

• Guidance for products adding residual efficacy claims (US EPA)

That guidance supports residual bactericidal and virucidal claims on hard, non-food contact surfaces for biocides with 24-hour residual claims.

Note: This guidance does not address residual disinfection claims against mycobacterium, fungi, yeasts or bacterial spores. It is also limited to biocides for use on hard, non-porous, non-food contact surfaces and does not address biocides for use on textile (porous) surfaces. Contact us to discuss testing requirements for other types of residual claims.