ASTM E2752-10 (2015). Standard Guide for Evaluation of Residual Effectiveness of Antibacterial Personal Cleansing Products.

Test accredited by ENAC (Spanish National Accreditation Entity). 

Test with the Certificate of Good Laboratory Practices (GLPs).

The importance in the maintenance of personal hygiene, to prevent, among others, the development and spread of infections, diseases and odors, requires to evaluate the effectiveness of products used for personal hygiene. This procedure is specifically designed to demonstrate the effectiveness of a personal antibacterial cleaning product, evaluating the reduction of the number of a marker organism (representing the transients), both immediately and after a prolonged exposure to washing (cleaning), using it under the conditions of use indicated by the client. In turn, the effect of residual antibacterial activity can be demonstrated by inhibiting the proliferation of bacteria in the skin after a period of contact with the product.

This test uses hand contamination of at least fifteen adult subjects (for each combination of test substance to be analyzed). The subjects will refrain from using any product that contains antimicrobial agents, both oral and topical, for at least one week before the test, providing them with a personal grooming kit, without antimicrobial products, of exclusive use during the trial. The hands of the fifteen subjects who do not have cuts or abrasions and fingernails that are cut and clean, are washed several times with the test product, and subsequently, contaminated. This method provides the option of using any of the following test organisms: Escherichia coli ATCC 11229 or Staphylococcus aureus ATCC 27217.

The antibacterial product, whether it is a wipe, liquid soap or a product that does not require rinsing, is evaluated after several test applications for three days and three times a day, programming the applications with at least one hour difference between them. The standard offers up to nine applications, but may be determined more or less depending on the objectives of the product to be analyzed. The selected test areas are washed several times with the cleaning product or vehicle. After washing, these zones are inoculated with a marker organism and are occluded for a specific period of time after which they are sampled and evaluated. The residual activity is determined at any selected time, after the last treatment application, by inoculating the organism into three different test zones. The exposure time could be 30 min, 2 hours and 5 hours but will depend on the manufacturer's instructions. Each inoculated zone will be sampled to determine the survival of the organisms, in this way, the residual antibacterial activity is evaluated in each evaluation interval, comparing the counts of CFU by the statistical method of Wilcoxon.

The customer must choose a contact time, a test concentration or manufacturer's instructions on how to add the product, in addition, the number of applications of the test substance that is required to incorporate into the test. The applicant for the test must record these requirements in the submission form.