ASTM E3273-21 PDF

SIGNIFICANCE AND USE 5.1 This practice is to help in the development of protocols to assess the survival, removal and/or inactivation of human pathogens or their surrogates in indoor air. It accommodates the testing of technologies based on physical (for example, UV light) and chemical agents (for example, vaporized hydrogen peroxide) or simple microbial removal by air filtration or a combination thereof. 5.2 While this practice is designed primarily for work with aerobic, mesophilic vegetative bacteria, it can be readily adapted to handle other classes of microbial pathogens or their surrogates. 5.3 The pieces of equipment given here are as examples only. Other similar devices may be used as appropriate. SCOPE 1.1 This practice is to assess technologies for microbial decontamination of indoor air using a sealed, room-sized chamber (~24 m3) as recommended by the U.S. Environmental Protection Agency (3). The test microbe is aerosolized inside the chamber where a fan uniformly mixes the aerosols and keeps them airborne. Samples of the air are collected and assayed, firstly to determine the rates of physical and biological decay of the test microbe, and then to assess the air decontaminating activity of the technology under test as log10 or percentage reductions in viability per m3 (1). The air temperature and relative humidity (RH) in the chamber are measured and recorded during each test. 1.2 The chamber can be used to assess microbial survival in indoor air as well as to test the ability of physical (for example, ultraviolet light) and chemical agents (for example, vaporized hydrogen peroxide) to inactivate representative pathogens or their surrogates in indoor air. 1.3 This practice does not cover testing of microbial contamination introduced into the chamber as a dry powder. 1.4 This practice does not cover work with human pathogenic viruses, which require additional safety and technical considerations. 1.5 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. 1.6 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.