(FAQ12) The Use of products for emergency disinfection of public water supplies.


In the past disinfectants for use in emergencies have been considered for approval under Regulation 31 of the Water Supply (Water Quality) 2000/2001, based solely on consideration of any potential risk to human health. No consideration has been given to the effectiveness of the disinfectant in controlling microorganisms in any situation, including in buildings.

Recently the Inspectorate has reviewed this practice, taking into account the requirements of the Biocidal Products Regulations 2001. The Inspectorate also took into account –

  • official complaints from government departments, local authorities and health authorities concerning inappropriate claims being made by marketing organisations about the suitability of emergency disinfectants listed in the “List of Approved Products for use in Public Water Supply” for continuous use in building water systems
  • the move to more risk-based regulation

The review concluded that the current practice of approving disinfectants for emergency use is no longer in line with recognised good practice and that it should be replaced by a process based on a detailed risk assessment by the water undertaker for each use. Following 6 months notice of the revocation of the approval of these products the “List of Approved Products for use in Public Water supplies in the United Kingdom” no longer includes any listing of disinfectant for use in an emergency.

Building Water Systems

Under the Water Supply (Water Quality) Regulations the remit of the Drinking Water Inspectorate is limited to drinking water quality between the source and delivery to the consumer’s premises. We are unable to comment on the use of products in contact with drinking water within buildings.

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