Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

The substance (Polyphosphoric acids, esters with triethanolamine, sodium salts) has been assessed for abiotic degradation (hydrolysis) and biodegradation.

The substance has been found to be not readily biodegradable (cannot be considered to have the potential for biodegradation in the marine environment) from an test conducted to OECD Guidelines No 306, "Biodegradability in Sea Water; Closed Bottle Test".

A hydrolysis as a function of pH (abiotic degradation) study showed less than 10% hydrolysis was observed after 5 days at 50°C at pH 4, 7 and 9, equivalent to a half-life of greater than 1 year at 25°C, indicating the substance is stable in the aqueous environment and will not rapidly hydrolyse.

However, in case of hydrolysis of the substance occurring in the aqueous environment, it is worth considering the environmental fate of the resulting substances that would be formed. Hydrolysis of the substance (Polyphosphoric acids, esters with triethanolamine, sodium salts) would be expected to result in the formation of the degradation products triethanolamine and phosphoric acid.

Both of these potential degradation products (triethanolamine and phosphoric acid) have previously been assessed and neither are classified or PBT/vPvB substances.

The inorganic phosphate (phosphoric acid) will be available to enter the general phosphate pool of the water and is not a cause for concern and is critical to normal physiological function.

Available data on triethanolamine shows it to be of low toxicity to fish, invertebrates, crustaceans and algae, and is not expected to bioaccumulate in the environment (based on low Kow, high water solubility and degradable nature).

Therefore, although studies conducted on the substance (Polyphosphoric acids, esters with triethanolamine, sodium salts) show it to be relatively stable and not to hydrolyse rapidly or be readily biodegradable, if hydrolysis/degradation was to occur the substance would be anticipated to biodegrade to products which are not environmentally hazardous.