WARNING — Handling and manipulation of microorganisms which are potentially hazardous requires a high degree of technical competence and may be subject to current national legislation and regulations. Only personnel trained in microbiological techniques should carry out such tests. Appropriate practices for disinfection, sterilization and personal hygiene must be strictly observed. This International Standard specifies a method of evaluating the antibacterial activity of antibacterial-treated plastics, and other non-porous, surfaces of products (including intermediate products). It is not intended to be used to evaluate the effects and propagation of bacteria on non-porous surfaces without antibacterial treatments. ISO 846[1] describes tests to evaluate the effects and propagation of bacteria on non-porous surfaces, which are different from those covered by this International Standard (see e.g. ISO 846:1997, method C). Secondary effects of antibacterial treatments, such as the prevention of biodeterioration and odour, are not covered by this International Standard, which is not intended to be used or referenced as a method to document or claim biodegradability of, for instance, plastics materials. In the case of plastics, biodegradation is covered in ISO 14851[2], ISO 14852[3] and ISO 14855[4] and related standards. Building materials are excluded, except where they are used in the same manner as treated articles.Antibacterial-treated textile products are excluded, even if the surfaces are coated or laminated (such products are covered by ISO 20743[5]). Photocatalytic materials and products are excluded (such materials and products are covered by ISO 27447[6]).