ASHRAE drives legionella standard

USA: As ASHRAE prepares to publish its first standard for the risk management of legionella in building water systems, an unexpected new source of the disease has been identified.

Nearly 40 years after legionnaires’ disease first gained public attention, the disease remains common throughout the world. Recent cases include outbreaks in Australia, Canada and the United States.

As a result, ASHRAE continues work on what would be the first set of standardised requirements specific to the building industry for management of the risks associated with amplified growth of and exposure to legionella.

Standard 188P, Legionellosis: Risk Management for Building Water Systems, currently under development, will identify risk factors for growth and exposure along with measures to mitigate that risk. The standard will help facility managers/owners understand how to evaluate the design and operation of their building water systems to reduce the risk of legionellosis.

Tom Watson, chair of the Standard 188P committee, said he is optimistic that a fourth public review draft, which has been substantially rewritten from previous versions, will be approved and made available during the summer.

“The new version of the standard will provide the building community with reasonable and practical methods to control exposure to the bacterium that could cause harm,” Watson said. “Effective design, maintenance and operational procedures that avoid amplification and dissemination of legionella are necessary throughout the life of a building to reduce the risk of the disease.”

Meanwhile, research by the American Society for Microbiology has found that legionella may be able to grow in windscreen washer fluid. In tests, the disease was isolated in nearly 75% of school buses in one district in Arizona.