1.1 This practice will define test conditions to evaluate ultraviolet germicidal irradiation (UVGI) light devices (mercury vapor bulbs, light-emitting diodes, or xenon arc lamps) that are designed to kill/inactivate microorganisms deposited on inanimate carriers.1.2 This practice defines the terminology and methodology associated with the ultraviolet (UV) spectrum and evaluating UVGI dose.1.3 This practice defines the testing considerations that can reduce UVGI surface kill effectiveness, that is, presence of a soiling agent.1.4 This practice does not address shadowing.1.5 This practice should only be used by those trained in microbiology and in accordance with the guidance provided by Biosafety in Microbiological and Biomedical Laboratories (5th edition), 2009, HHS Publication No. (CDC) 21-1112.1.6 This practice does not recommend either specific test microbes or growth media. Users of this practice shall select appropriate test microbes and growth media based on the specific objectives of their UV antimicrobial performance evaluation test plan.1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.8 Warning—Mercury has been designated by many regulatory agencies as a hazardous substance that can cause serious medical issues. Mercury, or its vapor, has been demonstrated to be hazardous to health and corrosive to materials. Caution should be taken when handling mercury and mercury-containing products. See the applicable product Safety Data Sheet (SDS) for additional information. Users should be aware that selling mercury or mercury-containing products, or both, may be prohibited by local or national law.1.9 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.10 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.