2 Scope

2.1 This procedure specifies selection procedures for tests and criteria for results to demonstrate resistance of a product or material to microbial growth. Quantifiable resistance to microbial growth shall be required to support a claim of microbial resistance. This procedure requires use of a standardized test method(s) or procedure(s) to support the claim. If a microbial resistance certification program is available for a specific product or material category, then validation shall be conducted under that program. Microbial growth in this procedure refers to colonization of a surface or material by bacteria, fungi or algae. This procedure does not address viruses, or any aspect of viral biology. This procedure is intended to support microbial resistance claims pertaining to plastic, metal, and ceramic products or other materials if a quantifiable and standardized test method or procedure can be used for the product or material.

Relevant products or materials for microbial resistance claims are those that may fail in their function if microbially colonized. That is, the product or material becomes unable to perform as designed (e.g. a manufactured wood panel delaminates and loses the ability to support weight or electrical contacts are fouled and can no longer conduct or break contact). A microbial resistance claim is not relevant to products or materials that may continue to function if microbially colonized but that may serve to transfer colonized microbes to people in contact with the product or material. Transfer of microbes to people or the ability to prevent such transfer are considered antimicrobial claims in nature and are not within the scope of UL 2282.

This procedure addresses products qualifying under the ‘treated article exemption’ (40 CFR152.25(a)).

Relevant test methods include challenges with environmental biodegradation species rather than microbial species relevant to public health. Biodegradation species that are regarded as biosafety level 1 (BSL1) organisms – those not known to cause disease in healthy adult humans – must be used in microbial resistance testing.

Additional information on the treated article exemption is available at these sources:

1. 1) https://www.epa.gov/pesticide-registration/prn-2000-1-applicability-treated-articles-exemption-antimicrobial-pesticides

2. 2) https://www.epa.gov/safepestcontrol/consumer-products-treated-pesticides

2.2 Some standardized test methods that can be used to assess resistance to microbial growth may refer to antimicrobial properties. If used for this procedure, such methods will only assess the susceptibility or resistance to growth on the tested product, not antimicrobial properties.

2.3 This procedure includes three parts. These are: a feasibility assessment, testing of the product and then comparison of results to the criteria for resistance.