Water Supply Industry Interpretations and Advice

  • Area of Interest : Backflow prevention
  • Topic : Fluid category
  • Title : Backflow protection requirements for reverse osmosis units
  • Clause Reference : Schedule 2 paragraph 15 & G15.3
  • Reference Number : B38
  • Decision Date : May 2007

Domestic reverse osmosis units and small scale industrial reverse osmosis units using replaceable cartridges are regarded as a fluid category 3 risk.

Reverse osmosis units that employ larger scale industrial processes which use chemical additives, for example to clean the reverse osmosis membrane are, depending upon the outcome of a risk assessment, either a fluid category 4 or 5 risk.