This Standard provides type test methods for evaluating the effectiveness of treatment methods intended to improve or maintain the microbiological quality of procedural water from dental units under laboratory conditions. This Standard does not apply to devices intended to deliver sterile procedural water or sterile solution. It also does not apply to lines, tubing or hoses that deliver compressed air within the dental unit. This Standard does not establish specific upper limits for microbial contamination or describe test methods to be used in clinical situations. It also does not establish test methods for evaluating any deleterious side effects potentially caused by treatment methods. The test methods provided in this International Standard may be used to test other dental equipment that delivers non-sterile water to the oral cavity.