Chloride
Chloride is ubiquitous in natural waters and is essential in a wide range of biological functions, including facilitating a variety of ion-exchange mechanisms through trans-membrane chloride channels. It forms salts with each of the major cations (Na, K, Ca, and Mg), but is highly soluble and exists primarily in the environment as a dissociated monovalent anion. Freshwater organisms are generally hyperosmotic in their internal fluids relative to the external environment and maintain an active gradient of chloride across membranes through use of active pumps and/or bicarbonate exchange mechanisms at exterior surface. (ref. ID; 7131)
Toxicity
Toxicity may result from osmotic stress related to overall ionic strength or disruption of individual cellular processes. The toxicity of chloride is in aquatic environments as a result of its tendency to occur at elevated concentrations in effluents from industrial operations that involve subsurface mining (including coal, potash, metal, and diamond mines), and oil and gas extraction. In addition, chlroide salts are widely used in road salts and, consequently stormwater and snow-melt runoff contain high concentrations of chloride in areas of application. (ref. ID; 7131)
Test organisms
Rotifera: Brachionus calyciflorus (ref. ID; 7131)
Oligochaeta: Lumbriculus variegatus (ref. ID; 7131)
Oligochaeta: Tubifex tubifex (ref. ID; 7131, 7134)
[Chlorine, Cl-]
Test organisms
Protozoa: Community (ref. ID; 955)
[Chlorinated wastewater]
Test organisms
Protozoa: Uronema nigricans (ref. ID; 6092)
[Sodium Chlorate] CAS[7775-09-9] UN1495
Chemical formula
NaClO3
Trade name
Chlorex
Purpose for use
Herbicide for complete eradication of weeds in uncultivated soil. (ref. ID; 496)
Test organisms
Protozoa: Blepharisma undulans (ref. ID; 496)
Protozoa: Colpoda cucullus (ref. ID; 496)
Protozoa: Oikomonas termo (ref. ID; 496)
[Sodium Chloride] CAS[7647-14-5]
Chemical formula
NaCl
Test organisms
Oligochaeta: Eisenia fetida (ref. ID; 6895, 7012, 7145)
Oligochaeta: Tubifex tubifex (ref. ID; 6968)
Nematoda: Caenorhabditis elegans (ref. ID; 7002)
[Sodium Hypochlorite] CAS[7681-52-9]
Trade name
Sodium hypochlorite (J): Chlorox
Chemical formula
NaOCl
Purpose for use
Fungicide, bactericide.
Test organisms
Rotifera: Brachionus calyciflorus (ref. ID; 127)