SPRI Home About SPRI

Phosphorus - total as P

SPRI Emission Reporting Threshold
5,000 Kg/yr Pollutant Emissions to Land
5,000 Kg/yr Pollutant Emissions to Water
5,000 Kg/yr Pollutant Emissions to Waste Water
Disclaimer
This sheet is a generic summary, designed to give the reader a basic level of background information about the substance in question. Great care has been taken to represent as effectively and correctly as possible the broad range of (not necessarily consistent) information which is available from a variety of sources. The reader must accept therefore that this sheet has no legal status and cannot be relied upon in any legal proceedings. SEPA disclaims any responsibility or liability whatsoever for errors and omissions in this sheet.
What is it?
"Total phosphorus" refers to any chemical compounds containing phosphorus. The main types released to the environment are inorganic phosphates (primary, secondary or tertiary), which are produced from phosphoric acid (a colourless, oily, thick liquid with an acidic smell).
What is it used for?
Phosphoric acid is used mainly to produce phosphates, as well as for rust-proofing metals, in sugar-refining and in the production of soft drinks. Phosphates are used in fertilisers, in detergents, as water softeners, in pharmaceuticals and in food additives.
Where does it come from?
Phosphorus compounds occur naturally in all living organisms. Releases of excessive amounts of phosphorus into the environment are due to man's activities: from the application of fertilisers, human sewage, the use of detergents and from industry.
How might it affect the environment?
An excess of phosphorus-containing substances in water bodies causes damage through eutrophication. Eutrophication occurs when increased levels of phosphorus lead to excessive growth of algae. The resulting "algal bloom" chokes other aquatic life (plants, fish and other organisms), starving them of oxygen and other nutrients and blocking sunlight. Phosphates also persist for long periods in aquatic environments and are recycled back into the environment when plants decompose.
How might exposure to it affect human health?
Exposure to environmental concentrations of phosphorus-containing compounds are unlikely to harm human health. Indirectly however, risks are posed by algal toxins produced in eutrophic waters and by increased exposure to potentially damaging forms of toxic metals in acidified waters.
What steps are being taken to limit the potential impacts?
A number of European Directives control releases of phosphates: waste water treatment (91/271); quality of bathing waters (76/160); pollution of aquatic environments (76/464/EEC); treatment of hazardous wastes (91/689/EEC); protection of groundwater against pollution (80/68/EEC). These must be implemented in the UK, including Scotland.