Chlorides (as total Cl)

Cl-tot, Klorider, som Cl

 Chlorides are a group of substances composed of chlorine and another element. Sodium chloride (table salt), potassium chloride and calcium chloride are white, solid substances that are readily soluble in water. Hydrogen chloride is a toxic, colourless gas with a pungent odour that is readily soluble in water and that forms hydrochloric acid in water solution.¹

Uses

In addition to flavour enhancer in food, sodium chloride is used for example to salt roads to remove ice and in production of chlorine and caustic soda.² Potassium chloride is for example used in production of fertilizer, explosives and as food additive.³, ⁴ Hydrogen chloride is used for many different applications, for example cleaning, preservation of food, electroplating, leather tanning and for production of a number of different products.⁵

Sources and transportation pathways

Chloride is a common substance in the environment, primarily in the ocean and in minerals, where it occurs as for example sodium chloride, potassium chloride, and it is very mobile in the environment.⁶ Anthropogenic emissions of chlorides arise for example from road salting, agriculture and sewage.⁷ Hydrogen chloride can be emitted during volcanic eruptions and can also form during combustion of many different plastics.⁸

Effects on environment and health

High concentration of chloride in soil is harmful for plants as it reduces the photosynthetic capacity. Different chloride compounds affect the environment and humans differently. Hydrogen chloride is for example acutely toxic and forms corrosive hydrochloric acid in contact with water. Emissions of large quantities of salt to freshwater lakes and watercourses may disturb the ecosystem. Road salt can cause salty soil that can damage vegetation.

Chloride is an essential element and necessary for the cell function.⁹ It is not known whether intake of large quantities of chloride is harmful for humans.¹⁰

International agreements and regulations

The UN Protocol on PRTRs and the EU E-PRTR regulation regulate how data on emissions of chlorides (as total Cl) is made available.

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¹ https://rib.msb.se/Portal/Template/Pages/Kemi/Kemsearch.aspx
 ² https://minerals.usgs.gov/minerals/pubs/commodity/salt 
 ³ https://www.canada.ca/en/health-canada/services/publications/healthy-living/guidelines-canadian-drinking-water-quality-guideline-technical-document-chloride.html
 ⁴ https://pubchem.ncbi.nlm.nih.gov/compound/4873#section=Uses
 ⁵ https://www.atsdr.cdc.gov/substances/toxsubstance.asp?toxid=147
⁶ https://www.canada.ca/en/health-canada/services/publications/healthy-living/guidelines-canadian-drinking-water-quality-guideline-technical-document-chloride.html
⁷ http://www.who.int/water_sanitation_health/dwq/chloride.pdf
⁸ https://www.atsdr.cdc.gov/substances/toxsubstance.asp?toxid=147
⁹ http://www.who.int/water_sanitation_health/dwq/chloride.pdf
¹⁰ https://www.canada.ca/en/health-canada/services/publications/healthy-living/guidelines-canadian-drinking-water-quality-guideline-technical-document-chloride.html