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Laundry Additives - Disinfection and Sanitization

DIS/TSS-13, April 4, 1980
Laundry Additives - Disinfection and Sanitization

The following requirements apply to antimicrobial products which bear label claims or recommendations for use in the treatment of laundry to provide disinfecting or sanitizing activity for fabrics and/or laundry water. Label claims must distinguish between products recommended as soaking treatments prior to laundering and products represented as additives in actual laundry operations.

  1. Pre-soaking treatments
  2. Products recommended for pre-soaking soiled fabrics prior to routine laundering must be shown to be effective by appropriate tests (e.g. AOAC Use Dilution Method for disinfectants; Sanitizer Test for inanimate non-food contact surfaces for sanitizers) in the presence of organic soil (e.g. 5% blood serum). The directions for use must specify rinsing of the items to remove gross filth prior to soaking, followed by complete immersion in an adequate volume of soaking solution (at least 5:1 w/w solution to fabric ratio, e.g. half a washload in a 3 - gallon pail) at the recommended use dilution for a specified contact time prior to the laundering operation.

  3. Laundry operations.
  4. A clear distinction should be made on the label between products recommended for household and coin-operated laundering and products represented as commercial-industrial-institutional laundry additives. The water to fabric ratio in home or coin-operated machines is about 10:1 (w/w), whereas in industrial laundering operations the ratio is about 5:1. The effectiveness of products may be significantly altered by these differences; thus, demonstrated e£ficacy in one system may not be able to be extrapolated to the other. In addition, directions for use of household laundering products may require different dosages for front-loading automatics (e.g. 8-10 gallon water capacity) and top-loading automatics and wringer-type washers (e.g. 12-15 gallon water capacity). Product dosages, in this instance, should be specified in household measurements. Dosage instructions for industrial laundering may be based on pounds of dry fabric.

    The directions for use of laundry additives should specify the machine cycle in which the product is to be added, water level, temperature range, and treatment time. Compatibility of the treatment with other common laundry additives (e.g. soaps, detergents, bleach, starch, bluing, sours, fabric softeners) should be determined in testing and addressed in labeling, when applicable.

    Efficacy data requirements for disinfectants and sanitizers intended for use as additives in laundry operations are as follows:

    1. Disinfection

      1. Test standard.
      2. A proposed simulated use procedure employed by Petrocci and Clarke (Petrocci, A. M. and Clarke, P. 1969. Proposed Test Method for Antimicrobial Laundry Additives. J.A.O.A.C. 52: 836-42) is acceptable. Alternately, a simulated-use study utilizing washing machines may be employed. The following basic elements must be incorporated in either study:

        1. The test bacteria are Staphylococcus aureus(ATCC 6538) and Klebsiella pneumoniae(ATCC†4352). If the product is intended for use on hospital linens, it must also be tested against Pseudomonas aeruginosa(ATCC 15442).

        2. The basic bacteriological procedures must be the same as those specified in the Petrocci and Clarke protocol.

        3. Tests must be conducted with 3 product samples, representing 3 different batches, one of which is at least 60 days old. Each sample must be tested with 9 fabric swatches against each of the specified test bacteria.

        4. The method employed must be designed to include testing both the fabric and the laundry water (5ml from the automatic washer, or 0.5 ml from the simulated washing device in individual widemouth jars containing subculture media and neutralizers. The laundry water-to-media volume ratio must not exceed 1:40.

        5. Growth or no-growth must be recorded and reported after a 48-hour incubation period.

      3. Performancestandard.
      4. There must be no growth in the fabric subcultures and no growth in the subcultures from the laundry water with all test bacteria.

    2. Sanitization.

      1. TestStandard.
      2. The same type of studies referred to under "Disinfection" above must be employed for evaluating the efficacy of laundry additives intended to sanitize laundry, with the following exceptions:

        1. Tests must be conducted with 3 samples representing 3 product batches, one of which is at least 60 days old. Each sample must be tested with 3 cloth swatches against each test microorganism required.

        2. Quantitative bacteriological assays must be conducted and the results reported.

      3. Performance standard.

The data requirements outlined herein do not apply to sodium-calcium hypochlorites, sodium-potassium dichloro-s-triazinetriones or trlchloro-s-triazinetrione.

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