What type of substance is it?
Fluorine, a non-metallic chemical element, is very chemically reactive and is usually found in combination with metals in the form of salts. The most common inorganic fluorine compounds include calcium fluoride, sodium fluoride and hydrogen fluoride. Many of these fluorine compounds are toxic and can be harmful to wildlife.
How is it released?
Inorganic fluorine compounds are widespread in the natural environment but at very low levels. Most fluorides found in the environment are released from industrial activities, particularly from the metal and chemical sectors.
Detailed information
Scientific name:
Calcium fluoride, Sodium fluoride, Hydrogen fluoride
Other names:
Hydrogen fluoride (hydrofluoric acid), calcium fluoride, sodium fluoride
CAS Number:
7664-39-3: 7681-49-4: 7789-75-5
Fluorine occurs naturally in the environment in the combined form of fluorite (or fluorspar), cryolite and apatite. Most inorganic fluorine compounds are derived from fluorite. Fluorite can be found in the environment in seawater and rivers, grasses, and animal bones and tissues.
Major industrial uses of hydrogen fluoride include the synthesis of fluorocarbons (e.g., Freon and Teflon) and the production of aluminium fluoride and synthetic cryolite for use in aluminium refining. It is also employed in refining uranium for use as a nuclear fuel, in manufacturing various organic chemicals, and in producing stainless steel. Hydrofluoric acid is used extensively in various forms of glass and ceramic etching, and in the manufacture of light bulbs. Sodium fluoride is used in the controlled fluoridation of drinking-water, as a preservative in glues, in glass and enamel production, as a flux in steel and aluminium production, as an insecticide and as a wood preservative. Toothpaste and mouth rinses also have fluorides added to prevent tooth decay. Fluorides are also used in making ceramics, lubricants, dyes, plastics, and pesticides. Some skin medicines and cancer treatment drugs also contain fluorides.
Compounds such as sodium and calcium fluoride are usually found as white solids. Sodium fluoride dissolves easily in water while calcium fluoride does not. Hydrogen fluoride is a colourless, highly toxic and irritant gas. It readily dissolves in water, where it is also colourless at room temperature . Hydrofluoric acid is a water solution of hydrogen fluoride which is prepared by heating calcium fluoride in sulphuric acid, and is extremely corrosive. Hydrofluoric acid attacks glass and dissolves most minerals. Another compound is hydrofluosilicic acid which can combine with sodium and potassium to form salts called fluosilicates or silicofluorides.
Where is it released?
Fluorides are released into the environment naturally through the weathering and dissolution of minerals, in emissions from volcanoes and in marine aerosols. Most releases of inorganic fluorines into the environment are from anthropogenic sources. They are released into the environment via coal combustion and process waters and waste from various industrial processes, including steel manufacture, primary aluminium, copper and nickel production, phosphate ore processing, phosphate fertiliser production and use, glass, brick and ceramic manufacturing, and glue and adhesive production. The use of fluoride-containing pesticides as well as the controlled fluoridation of drinking-water supplies also contribute to the release of fluoride from anthropogenic sources. For hydrogen fluoride, most releases in the UK come from the energy production sector.
Local environmental effects
Fluorine compounds are found throughout the environment at very low levels. In areas where levels of inorganic fluorines are higher, for example, due to emissions to the atmosphere, harmful effects can occur due to bioaccumulation leading to toxicity in animals and harm to vegetation. Fluorides accumulate in the bone tissue of terrestrial vertebrates, depending on factors such as diet and the proximity of fluoride emission sources. They also accumulate in aquatic organisms directly from the water or to a lesser extent via food.
Global environmental effects
No significant global impacts are considered likely.
Possible health concerns
Excessive exposure to inorganic fluorine compounds may affect the bone, digestive system, eye, heart, lung, reproductive system, skin, teeth and throat. The Environment Agency aims to ensure that environmental exposures are too low to harm human health.
Legislation
Why was this substance selected for the Pollution Inventory?
Included in : European Pollutant Emission Register (EPER) reporting requirements.
Standard risk phrases for the pure substance
The standard risk phrases provided here are generally those used by suppliers of chemicals to describe substances - for example on packaging materials. The most important source of these phrases are the CHIP Regulations - Chemicals (Hazard Information and Packaging for Supply) - provided by the Health and Safety Executive. Some substances do not have CHIP risk phrases and in these circumstances we have used other risk phrases, the sources of which are indicated.
Because this is a large family of chemicals rather than a single substance, it is not possible to provide risk phrases, which are generally provided for a single substance whose properties can be precisely determined.
Controlling legislation and international agreements
European legislation includes: Council Directive 96/61/EC of 24 September 1996 concerning integrated pollution prevention and control Council Directive 91/689/EEC of 12 December 1991 on hazardous waste Council Directive 76/464/EEC of 4 May 1976 on pollution caused by certain dangerous substances discharged into the aquatic environment of the Community Releases of fluorine compounds are controlled under the UK Pollution Prevention and Control Regulations.
These factsheets have been compiled to provide users with information on the Pollution Inventory substances and represent our best efforts to summarise a large number of disparate and sometimes conflicting data sources. We emphasise that this information describes potential hazards rather than actual effects and that the Environment Agency seeks to regulate releases to minimise emissions and hence any risk of detrimental effects occurring.
