Fluid Categories

Guidance

Determination of fluid category 1

Wholesome water supplied by a water undertaker and complying with the requirements of regulations made under water section 67 of the Water Industry Act 1991.

Example:

• Water supplied directly from a water undertaker’s main.

Determination of fluid category 2

Water in fluid category 1 whose aesthetic quality is impaired owing to:

• a change in its temperature; or
• the presence of substances or organisms causing a change in its taste, odour or appearance, including water in a hot water distribution system.

Examples:

• Mixing of hot and cold water supplies
• Domestic softening plant (common salt regeneration).
• Drink vending machines in which no ingredients or carbon dioxide are injected into the
  supply or distributing inlet pipe.
• Fire sprinkler systems (without anti-freeze).
• Ice making machines.
• Water cooled air conditioning units (without additives).

Determination of fluid category 3

Fluid which represents a slight health hazard because of the concentration of substances of low toxicity, including any fluid which contains:

• ethylene glycol, copper sulphate solution, or similar chemical additives; or
• sodium hypochlorite (chloros and common disinfectants).

Examples:

• Water in primary circuits and heating systems (with or without additives) in a house.
• Domestic washbasins, baths and showers.
• Domestic clothes and dishwashing machines.
• Home dialysing machines.
• Drink vending machines in which ingredients or carbon dioxide are injected.
• Commercial softening plant (common salt regeneration only).
• Domestic hand held hoses with flow controlled spray or shut-off control.
• Hand held fertiliser sprays for use in domestic gardens.
• Domestic or commercial irrigation systems, without insecticide or fertiliser additives and with fixed sprinkler heads not less than 150mm above ground level.

Determination of fluid category 4

Fluid which represents a significant health hazard due to the concentration of toxic substances, including any fluid which contains:

• chemical, carcinogenic substances or pesticides (including insecticides and herbicides); or
• environmental organisms of potential health significance.

Examples:

• General
• Primary circuits and central heating systems in other than a house.
• Fire sprinkler systems using anti-freeze solutions.
• House gardens
• Mini-irrigation systems without fertiliser or insecticide application; such as pop-up
  sprinklers or permeable hoses.
• Food processing
• Food preparation.
• Dairies.
• Bottle washing apparatus.
• Catering
• Commercial dishwashing machines.
• Bottle washing apparatus.
• Refrigerating equipment.
• Industrial and commercial installations
• Dyeing equipment.
• Industrial disinfection equipment.
• Printing and photographic equipment.
• Car washing and degreasing plants.
• Commercial clothes washing plants.
• Brewery and distillation plant.
• Water treatment plant or softeners using other than salt.
• Pressurised fire fighting systems.

Determination of fluid category 5

Fluid representing a serious health hazard because of the concentration of pathogenic organisms, radioactive or very toxic substances, including any fluid which contains:

• faecal material or other human waste;
• orbutchery or other animal waste;
• orpathogens from any other source.

Examples:

• General
• Industrial cisterns.
• Non-domestic hose union taps.
• Sinks, urinals, WC pans and bidets.
• Permeable pipes in other than domestic gardens, laid below or at ground level, with or without chemical additives.
• Grey water recycling systems.
• Medical
• Any medical or dental equipment with submerged inlets.
• Laboratories.
• Bedpan washers.
• Mortuary and embalming equipment.
• Hospital dialysing machines.
• Commercial clothes washing plant in health care premises.
• Non-domestic sinks, baths, washbasins and other appliances.
• Food processing
• Butchery and meat trades.
• Slaughterhouse equipment.
• Vegetable washing.
• Catering
• Dishwashing machines in health care premises.
• Vegetable washing.
• Industrial and commercial installations
• Industrial and chemical plant etc.
• Mobile plant, tankers and gully emptiers.
• Laboratories.
• Sewage treatment and sewer cleansing.
• Drain cleaning plant.
• Water storage for agricultural purposes.
• Water storage for firefighting purposes.
• Commercial agricultural
• Commercial irrigation outlets below or at ground level and/or permeable pipes, with or without chemical additives.
• Insecticide or fertiliser applications.
• Commercial hydroponic systems.

Note: The list of examples of applications shown above for each fluid category is not exhaustive.

Recommendations

Fluid category 1

Water undertakers have a duty to supply water which complies with the Water Quality Regulations made under Section 67 of the Water Industry Act 1991, compliance with which ensures a wholesome water suitable for domestic or food production purposes and this quality is classified as fluid category 1. Therefore, wherever practicable, water for drinking purposes should be obtained directly from a supply pipe, that is, without any intervening storage before use.

Fluid category 2

Fluid category 2 is water which would be classed as fluid category 1 except that it has undergone a change in taste, odour, appearance or temperature. These changes in water quality are aesthetic changes only and the water is considered to present no human health hazard.

Typical applications of fluid category 2 water in domestic situations are:

• water heated in a hot water secondary system; and
• mixtures of fluid categories 1 and 2 water discharged from combination taps or showers; and
• water that has been softened by a domestic common salt regeneration process.

Note: Where a water softener is installed, water used for mixing with powdered milk for feeding babies should be drawn from an unsoftened water supply. A person on a sodium restricted diet should follow their doctor’s instructions regarding the drinking of softened water.

Fluid category 3

Fluids in category 3 represent a slight health hazard and are not suitable for drinking or other domestic
purposes.

Typical applications of a category 3 fluid are given below:

• In houses or other single occupancy dwellings;
• water in primary circuits and heating systems, whether additives to the system have been used or not; and
• water within washbasins, baths or shower trays; and
• clothes and dishwashing machines; and
• home dialysing machines; and
• hand held garden hoses with flow controlled spray or shut-off control; and
• hand held fertiliser sprays.
• In premises other than single occupancy dwellings;
• Where domestic fittings, wash as washbasins, baths or showers are installed in premises other than single occupancy dwellings, that is, commercial, industrial or other premises, these appliances may still be regarded as fluid category 3, unless there is a potential higher risk. Typical premises in which some, or all, of these appliances may be regarded as justifying a higher fluid risk category include hospitals and other medical establishments.
• House garden or commercial irrigation systems, without insecticide or fertiliser additives, and with fixed sprinkler heads not less than 150mm above ground level.

Fluid category 4

Fluid category 4 represents a significant health hazard and is not suitable for drinking or other domestic purposes.

‘Carcinogenic substances’ are those that may, on prolonged exposure, cause cancer.

‘Environmental organisms’ refer to micro-organisms, bacteria, viruses and parasites of significance for human health, which can occur or survive in the general environment e.g. Legionella or Cryptosporidium.

Some typical general applications of fluid category 4 are:

• water in primary circuits and heating systems in other than a house, irrespective of whether additives have been used or not; and
• water treatment or softeners using than salt; and
• clothes and dishwashing machines for other than domestic use (see Section 6: Clause R15.16); and
• mini-irrigation systems in house gardens without fertiliser or insecticide application such as pop-up sprinklers, permeable hoses or fixed or rotating sprinkler heads fixed less than 150mm above ground level.

Fluid category 5

Fluid category 5 represents a serious health hazard and is the most polluting category listed.

‘Pathogenic organisms’ are micro-organisms such as bacteria, viruses or parasites which are capable of causing illness, especially in humans e.g. Salmonella, Vibrio cholera, Campylobacter. They generally arise in living creatures and may be released into the environment, for example, in faecal matter, animal wastes or body fluids.

Some typical general applications of a fluid category 5 risk are:

• sinks, urinals, WC pans and bidets in any location; and
• permeable pipes or hoses in other than domestic gardens, laid below or at ground level, with or without chemical additives; and
• grey water recycling systems; and
• clothes and dishwashing machines in high risk premises (see Section 6: Clause R15.16).

The principle distinction between fluid categories 4 and 5 is that the toxicity or concentration of substances in category 4 fluids is such that a prolonged period of exposure (days to weeks to months) is generally necessary before serious harm to health occurs. Category 5 fluids are those which contain substances with higher toxicity or at greater concentration than category 4, resulting in them causing harm to health after short exposures (e.g. a single or brief (minutes to hours) exposure).