WRAS, which stands for Water Regulations Advisory Scheme, is a certification mark that demonstrates that an item or package complies with the high standards set out by water regulations.
The installation and use of washing machines and dishwashers in premises connected to the public water supply are subject to the Water Supply (Water Fittings) Regulations 1999 in England and Wales and the technically identical Byelaws 2000 in Scotland.
The water regulations say all appliances require adequate backflow protection to prevent contamination of the pipework supplying them. To help understand this they have broken it down into five sections (known as fluid categories).
- Fluid category 1 – Is wholesome clean drinking water supplied to the property by the relevant utility company for that area.
- Fluid category 2 – This starts as category 1 water that has then been impaired by a change in temperature or has been contaminated by the presence of organisms causing a change in taste, odour, or appearance. This would typically be a hot water system in a property.
- Fluid category 3 – Is water that might represent a slight health hazard due to the presence of chemical additives. This category typically applies to the water that is contaminated by the detergents used by domestic washers and dishwashers.
- Fluid category 4 – Is water that represents a significant health hazard due to the presence of toxic substances such as carcinogenic chemicals and pesticides. This category typically applies to commercial washers and dishwashers used in the hospitality sector.
- Fluid category 5 – Is water that represents a serious health hazard because of the concentration of pathogenic organisms, radioactive or very toxic substances, including any fluid which contains faecal matter, human waste, butchery or other animal waste. This is typically waste water.
Put simply any water from categories 2 – 5 are not allowed to backflow and contaminate water classified as category 1 which is clean safe drinking water. Luckily for us, domestic washers and dishwashers have an air brake system built into the design of the appliance in the form of a dispenser on a washing machine and an air brake/metering tank on a dishwasher.
These devices allow the water to be gravity fed into the machine which means it is impossible for the water to backflow and contaminate the drinking water. In the event of a backflow scenario the water would just flow out onto the customer’s floor which is definitely an inconvenience but I am sure we can all agree this is preferable to it contaminating the drinking water.