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.