Questions and Discussion on Treated Articles

Questions For SAP

1. If the Agency were to consider registration of treated articles with public health claims, especially for food contact surfaces, are the existing test methodologies and efficacy performance standards appropriate to determine the efficacy of such articles against pathogenic organisms?

2. For most treated articles the presence of moisture is a key factor in activating the antimicrobial agent against microorganisms. For those situations where the surfaces are routinely dry and the antimicrobial agent releases slowly, are there acceptable or recommended methodology(ies) and performance standards for determining efficacy of public health claims, under such conditions?

3. Is the state-of-the-science such that the Agency needs to develop new test methodologies and/or efficacy performance standards for treated articles with public health claims?

Discussion

I.Introduction

For purposes of the following discussion on "treated articles" some of the major terms used throughout this discussion are described as follows:

"Treated articles" typically refer to articles or substances which are impregnated with, or have antimicrobial pesticide incorporated into them, to protect the articles or substances themselves (e.g., paint, rubber gloves, rubber conveyer belts, plastic shower curtains, rubber gaskets). Incorporation or impregnation usually occurs during manufacture of the article (e.g., plastic shower curtain); however, it also can occur after manufacture but prior to use of the article (e.g., incorporation of pesticide into a paint). Thus, there are a variety of treated articles. Also, most efficacy claims for "treated articles: are considered "residual" because efficacy can occur over an extended time period; whereas efficacy claims for non-treated articles are considered "non-residual" since efficacy usually occurs over a shorter time period.

"Non-treated articles" refer to articles, surfaces, or other inanimate objects which are not impregnated with, or have antimicrobial pesticide incorporated into them during, or after, manufacture. These inanimate objects, which include hard, non-porous surfaces (e.g., plastic utensils), typically are treated with the more conventional antimicrobial pesticides (e.g., sanitizing sprays, sanitizing rinses).

"Antimicrobial" means the property of any pesticide to prevent, destroy, or mitigate any bacteria, pathogenic fungi, or viruses in any environment except those on or in living man or other animals; those on or in living plants or the substrate in which they grow; and those on or in processed food, beverages, or pharmaceuticals including cosmetics. Antimicrobial products include sterilizers, disinfectants, virucides, tuberculocides, algicides, sanitizers, bacteriostats, and fungicides used against fungi that are pathogenic for man or other animals. The term "antimicrobial" is too general to meaningfully describe a specific level of antimicrobial activity.

"Sanitizer" means an agent that reduces contaminants in the inanimate environment to levels considered safe as determined by Public Health Ordinance, or that reduces the bacterial population by significant numbers where public health requirements have not been established. Sanitizers meeting Public Health Ordinance requirements are generally used on food contact surfaces and are recognized as sanitizing rinses.

"Residual self-sanitizing activity of dried chemical residues on hard-inanimate (e.g., plastic cutting board) surfaces" typically refers to: (1) significant reduction in numbers of infectious microorganisms which may be present or subsequently deposited on treated surfaces that are likely to become and remain wet under normal conditions of use; (2) surface chemical residues which occur when the antimicrobial pesticide, which has been incorporated into the treated article, leaches to the surface of the treated article.

"Impregnated self-sanitizing fabrics and textiles" typically refer to: (1) fabrics and textile materials, treated with an antimicrobial pesticide during the manufacturing process, to provide durable residual self-sanitizing activity (e.g., significant reduction in numbers of infectious microorganisms which may be subsequently deposited on the finished item) in the presence of moist or wet contamination; and (2) impregnation of chemical residues into the fabric and textile, but impregnation which likely results in surface chemical residues when the impregnated chemical leaches to the surface of the (treated) article.

"Bacteriostat" means an agent that inhibits the growth of bacteria in the inanimate environment in the presence of moisture, and in so doing, may or may not affect the viability of organisms.

II. Background

The Agency registers both public health and non-public health antimicrobial pesticide products. Public health pesticide products include all antimicrobial products intended to control microorganisms infectious for man in any area of the inanimate environment where these microorganisms may present a hazard to human health. For these products efficacy test data are required to be submitted to support registration. (Note: the label claims for an antimicrobial product determine whether or not it is considered to be related to human health.) Antimicrobial products which fall in the public health area include (but are not limited to) uses that : sterilize, disinfect, and sanitize. However, relative to "treated articles" and public health uses, only sanitizing claims (i.e., residual, self-sanitizing) are appropriate and apply.

For non-public health antimicrobial pesticide products (e.g., control of odor-causing bacteria), the Agency does not require submission of efficacy data. However, the registrant is still responsible for ensuring that these products perform as intended by developing efficacy data which must be kept on file. The Agency still has the responsibility of making sure that the use directions proposed for non-health related claims are appropriate and adequate. Therefore, the Agency retains the option of requiring the submission of efficacy data for non-health related claims, should a product or the use directions on the proposed label on a product pose reasonable doubt as to its efficacy as a non-public health related antimicrobial product. Antimicrobial products which fall in the non-public health area include preservation and bacteriostatic claims - that is, uses which control or inhibit: odor-causing bacteria; bacteria causing spoilage, deterioration, or fouling of materials such as paint or industrial fluids (i.e., preservation of materials); and microorganisms infectious only for animals, where product failure against the specified pests would not have human health consequences. However, relative to "treated articles" and non-public health uses, only uses which control odor-causing bacteria or bacteria causing spoilage, deterioration, or fouling of materials (i.e., preservation) are appropriate and apply.

However, the area of greatest interest to the Agency concerns treated articles with public health claims. The remainder of this discussion will focus on this area.

A. Public Health Uses - Sanitizing and Residual (Self-Sanitizing) Claims

As discussed earlier, sanitizing and self-sanitizing claims, concern public health uses. Such uses usually involve:

Non-treated articles - sanitizing (non-residual) claims for:

1a. Non-food contact (hard, inanimate) surfaces;
2a. Previously cleaned, food contact (hard, inanimate, non-porous only) surfaces;
3a. Pre-soak treatments of soiled fabrics prior to routine laundry operations;
4a. Additives for use during laundering;
5a. Carpets;
6a. Mattresses, upholstered furniture, and pillows.
7a. Air;
8a. Toilets (bowl and urinal surfaces, toilet and urinal bowl water, and toilet in-tanks); and

Treated (impregnated) articles - self-sanitizing (residual) claims for:

1b. Non-food contact (hard, inanimate) surfaces;
2b. Food contact (hard, inanimate, non-porous only) surfaces; and
3b. Impregnated fabrics and textiles.

Relative to the above uses, the Agency is facing scientific/technical issues concerning treated (impregnated) articles (i.e., uses 1b, 2b, and 3b above) with public health claims. Considering this, a brief discussion and comparison of existing Test Methods and Performance Standards (as outlined in Subdivision G, Product Performance/Efficacy Guidelines) is presented for uses 1a, 2a, 3a, and 4a versus uses 1b, 2b, and 3b. (However, the discussion concerning fabrics and textiles can be applied to carpets, mattresses, upholstered furniture, and pillows.)

1.Hard Inanimate Surfaces

a. Non-Treated (Sanitizing/Non-Residual Claims; Uses 1a and 2a Above)

Typically, the Agency registers liquid and spray sanitizers (with sanitizing claims) for use on non-food (e.g., floors, walls) and food (e.g., eating and drinking utensils) contact surfaces. Further, for food contact surfaces EPA has allowed only a two-step treatment process on hard, non-porous surfaces: (1) the user cleans the surface first to remove excessive dirt and filth; and (2) the user then applies the sanitizer as a terminal rinse to the surface.

For non-food contact sanitizers the recommended Test Method is the Sanitizer Test for Hard Inanimate Non-food Contact Surfaces. The Performance Standard for this Test Method is as follows: EPA concludes efficacy is demonstrated when a reduction of at least 99.9% (a 3-log reduction) in the number of each test microorganism over the parallel control count is observed within 5 minutes.

For food contact sanitizers (non-halide products) the recommended Test Method is the AOAC Germicidal and Detergent Sanitizers Method. The Performance Standard for this Test Method is as follows: EPA concludes efficacy is demonstrated when a reduction of at least 99.999% in the number of each test microorganism over the parallel control count is observed within 30 seconds.

b. Treated (Self-Sanitizing/Residual Claims; Uses 1b and 2b Above)

For treated articles which carry residual self-sanitizing claims (e.g., significant reduction in numbers of infectious microorganisms which may be present or subsequently deposited on treated surfaces that are likely to become and remain wet under normal conditions of use), the recommended Test Methods are either a Controlled In-Use Study or Simulated In-Use Study. The Performance Standard for these Test Methods is as follows: EPA concludes efficacy is demonstrated when the number of test organisms on the test surface are reduced by 99.9% over that of parallel control surfaces(s).

However, note that the recommended Test Methods include the following elements:

1. The test microorganisms employed in the study must be pathogens that are likely to be encountered in the environment in which the product is to be used;
2. The residue on the treated surfaces must be activated by the addition of moisture in a manner and over an exposure period identical to the use pattern for which the product is intended;
3. The same type(s) of surfaces without the treatment must be employed in the test and inoculated in a manner and over an exposure period identical to the use pattern for which the product is intended;
4. The environmental conditions employed in the test (e.g., relative humidity and temperature) must be reported. These conditions must be the same as those likely to be encountered under normal conditions of product use. Tests should also include those environmental conditions that would act to reduce the effective concentration of the product on the inanimate surface (e.g., rinsing, abrasion, organic load, repeated challenges by microorganisms, etc.); and,
5. The length of time the residual activity can be expected to exist under the expected use conditions must be documented.

2.Fabrics and Textiles

a. Non-Treated (Sanitizing/Non-Residual Claims; Uses 3a and 4a Above)

For non-treated fabrics and textiles sanitization uses involve "sanitizing pre-soak treatments" of soiled fabrics prior to routine laundry operations or "laundry additives (non-residual)" during laundering operations.

For sanitizing pre-soak treatments the recommended Test Method is the Sanitizer Test for Hard, Inanimate Non-Food Contact Surfaces, modified to include organic soil. The Performance Standard for this Test Method is as follows: EPA concludes efficacy is demonstrated when a reduction of at least 99.9% (a 3-log reduction) in the number of each test microorganism over the parallel control count is observed within 5 minutes.

For laundry additives (non-residual) the recommended Test Method is as follows: Petrocci and Clark Laundry Additives Method (sanitizing level); however, an actual in-use study utilizing washing machines also may be employed. The Performance Standard for this Test Method is as follows: EPA concludes efficacy is demonstrated when at least 99.9% reduction in bacteria over the control count for both laundry water and fabric is demonstrated against each test microorganism. (Note: these data requirements do not apply to sodium-calcium hypochlorites, sodium potassium dichloro-s-triazinetriones or trichloro-s-triazinetrione.)

b. Treated (Residual, Self-Sanitizing Claims): Impregnated Fabrics and Textiles; Use 3b Above)

Treated (impregnated) fabrics and textiles typically are treated during the manufacturing process to provide durable residual self-sanitizing activity (e.g., significant reduction in numbers of infectious microorganisms which may be subsequently deposited on the finished item) in the presence of moist or wet contamination. The recommended Test Method is a Simulated In-Use Study. The Performance Standard for this Test Method is as follows: EPA concludes efficacy is demonstrated when the number of test microorganisms on the test surface is reduced by 99.9% over that of the parallel control surface(s).

However, note that the recommended Test Methods include the following elements:

(1) The test microorganisms employed in the study must be pathogens that are likely to be encountered in the environment in which the product is to be used;
(2) The residue on the treated surfaces must be activated by the addition of moisture in a manner and over an exposure period identical to the use pattern for which the product is intended;
(3) The same type(s) of surfaces without the treatment must be employed in the test and inoculated in a manner and over an exposure period identical to the use pattern for which the product is intended;
(4) The environmental conditions employed in the test (e.g., relative humidity and temperature) must be reported. These conditions must be the same as those likely to be encountered under normal conditions of product use. Tests should also include those environmental conditions that would act to reduce the effective concentration of the product on the inanimate surface (e.g., rinsing, abrasion, organic load, repeated challenges by microorganisms, etc.); and,
(5) The length of time the residual activity can be expected to exist under the expected use conditions must be documented.

III. Scientific/Technical Issues - Public Health Uses

As presented above, the Agency has Test Methods and Performance Standards for both treated (impregnated) and non-treated articles and substances proposing public health uses. Over the years these methods and standards have worked well for non-treated articles where "typical" applications involve liquid and spray sanitizers applied to a variety of surfaces, but which also include application to water (see II.A.1a - 8a above).

However, in recent years there has been a tremendous surge in the number of treated (impregnated) articles proposed for registration, or use, with public health claims. The registration applications the Agency receives, as well as recent news articles and stories, published literature, and recent Agency enforcement actions (e.g., impregnated toys with public health claims), all demonstrate this. Further, it is our understanding that treated, or impregnated, articles with public health claims are commonly registered and sold outside of the United States.

Coupled with this trend is the following:

(1) To date, the Agency has registered only one treated article (antimicrobial-treated socks), which has non-food, public health claims and was able to achieve the Performance Standard for impregnated fabrics and textiles. The treated articles (socks) consist of the following types of fabrics/textiles: nylon, nylon/orlon, cotton/nylon, cotton/nylon, linen/Lycra, acrylic/polypropyline/nylon/Lycra, wool/silk/nylon/Lycra, and wool/acrylic/nylon/Lycra.

Examples of the claims the technical product (which is incorporated into the socks) makes are as follows:

Nylon/orlon....treated with.....will: (1) reduce 99.9% of the Trichophyton mentagrophytes (athlete's foot fungus) on the sock; (2) provide a self-sanitizing surface against the recurrence of athlete's foot fungus on the sock; (3) be sanitized against athlete's foot fungus; (4) inhibit the growth of athlete's foot fungus on the sock; (5) be treated with a self-sanitizer against athlete's foot fungus; (6) prevent the growth of 99.9% of athlete's foot fungus on the sock; (7) significantly reduce 99.9% of fungus on the sock that causes athlete's foot; (8) effectively sanitizes athlete's foot fungus on the sock; and (9) reduces the spread of athlete's foot fungus on the surface of the sock.

Residual self-sanitizing activity against athlete's foot fungus is durable for up to 10 repeated washings of the treated sock.

(2) To date, the Agency has registered no other treated articles that proposed food or non-food public health claims since none have been able to achieve the Performance Standard of 99.9% reduction under simulated or controlled use in-use conditions.

IV. Conclusion

Considering the above, the Agency is reexamining the test methodologies and efficacy performance standards that presently exist for treated articles. We believe, based on our experience, that these methods and standards appear appropriate for treated articles, and we are not proposing to change them. However, at the same time the existing guidelines are quite old and have never been published in final form. There may be advancements or improvements in the testing methodologies, or efficacy performance standards, for treated articles that the Agency is not aware of. Therefore, we have decided to allow for an open public discussion on this subject area. We request that the SAP consider the existing test methods and efficacy performance standards as feasible and realistic, but also ask for suggestions or guidance relative to the state-of-the-science for determining the efficacy of public health claims associated with treated articles.

Questions and Discussion on Treated Articles

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