ISO 22196: 2011 and JIS Z 2801: 2010 + A: 2012. Antibacterial activity on plastics and other nonporous surfaces.
Test accredited by ENAC (Spanish National Accreditation Entity).
This standard determines the activity and antimicrobial effectiveness of antimicrobial agents on plastic surfaces and other non-porous surfaces. This test is not intended to evaluate the effect and propagation of bacteria on non-porous surfaces which do not contain antimicrobial (this aspect is discussed in ISO 846 standard). It is not aimed at assessing the effects that may result in material antibacterial treatments, as could be the prevention of decay or odor, nor is directed to building materials, except when these are used in the same way as the materials treated. Materials and photocatalytic products (tested according to ISO 27447), and textile products with antimicrobial treatment are also excluded, but will be coated or laminated surfaces (ISO 20743 standard). The antibacterial activity test uses two bacteria: Staphylococcus aureus and Escherichia coli. These bacteria must be quantified and applied to the surfaces that are supposed to have antimicrobial, as well as control without antimicrobial surfaces, to find the reduction of bacterial load under the effect of existing antimicrobial surface. The surfaces of the products / materials to be used should be 50 mm square and flat pieces and a recommended thickness of about 10 millimeters. The standard establishes a mandatory 35 ± 1ºC temperature and optional further environmental temperature. In all tests at least 9 pieces must be assessed for each microorganism (6 parts without antimicrobial treatment for bacterial counts immediately controls after application and 24 hours, and 3 parts with antimicrobial treatment for 24 hours). From each application five dilutions in base 10 to obtain the number of bacteria present on each surface must be performed. This implies, for one test conditions, the following culturs are prepared: 2 bacteria x 9 different bacteria x 5 dilutions x 2 (duplicate) = 180 cultures with duplicate cultures. If also the ambient temperature is selected, the number of cultures would double = 360. The minimum number of cut pieces to be sent, in the case of the test with the two mentioned bacteria is 18 (9 for each bacteria), even though we request to send the double necessary in case we had to repeat some test (= 36).