SPRI Home About SPRI

Chlorine and total inorganic chlorine compounds - as HCl

chloride, chloride ion, hydrogen chloride, brine, saline (when in solution)

SPRI Emission Reporting Threshold
10,000 Kg/yr Pollutant Emissions to Air
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?
Chlorine is a reactive gas. It is usually found in the environment as chloride salts, which are highly soluble in water. Properties of chlorides depend on the nature of the metal component of the salt: For example, common table salt is sodium chloride, whilst a solution of hydrogen chloride is the highly corrosive hydrochloric acid .
What is it used for?
Chlorine is a major industrial chemical - mostly used to produce the widely-used PVC plastic. Rock salt (sodium chloride) is used for de-icing roads, in water softeners and as a flavour enhancer in cooking.
Where does it come from?
Releases of chlorides occur from industrial processes, in agricultural run-off, in landfill leachate, from road salting and from coal-ash waste deposits.
How might it affect the environment?
Plants and animals tolerate chlorides to different extents. Those found in marine environments are highly resistant, whilst releases of chloride into fresh water may damage aquatic life not used to saline conditions. Releases of chlorides are unlikely to have an effect remote from the point of emission.
How might exposure to it affect human health?
Exposure to levels of chlorine and chlorides commonly found in the environment are unlikely to harm humans. Low levels of chlorine are used to safely disinfect drinking and bathing waters. Exposure to extreme levels of chlorine (following an accidental release or in occupational settings) could cause burning of the eyes, nose and mouth, coughing, sneezing, nausea and vomiting, headaches and dizziness and irritation of the skin.
What steps are being taken to limit the potential impacts?
Releases of chloride in the UK (including Scotland) are controlled under the Pollution Prevention and Control (PPC) Regulations (96/61/EC) and the European Directive concerned with reducing air pollution from industrial plants (Directive 84/360/EEC).