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Ecotoxicological information

Toxicity to microorganisms

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Description of key information

Study was conducted according to OECD guideline 209, data are reliable without restrictions.

Key value for chemical safety assessment

EC50 for microorganisms:
1 000 mg/L
EC10 or NOEC for microorganisms:
1 000 mg/L

Additional information

The toxicity of the read-across substance 1-Octadecanol, phosphate, potassium salt on toxicity to microorganisms was tested in a study according to OECD guideline 209.

Activated sludge from a domestic sewage treatment plant was used as inoculum.

At the highest test item concentration 1000 mg/L, no statistically significant inhibition could be observed.

3h NOEC ≥ 1000 mg/L

3h EC20 > 1000 mg/L

3h EC50 > 1000 mg/L

Justification for read-across:

The main compounds of Phosphoric acid, C16-18-alkyl esters, potassium salts and 1-Octadecanol, phosphate, potassium salt are the mono and di-phosphoric esters.

The typical proportion of mono- to di-ester is 35 % to 50 % for both substances, respectively.

The only difference between the substances is varying chain lengths of the alkyl substituents, C16 and C18 or only C18.

Both substances are surfactants and have a polar “head” (the negatively charged phosphoric acid group) and a relatively inert hydrophobic “tail” (the long alkyl substituents).

The chemical behavior of both alkyl esters is expected to be very similar. The difference chain length of the alkyl substituent (C16 and C18 or only C18) is considered not relevant for the toxicological profile of the substances. This is proven by the close similarity of physico-chemical properties and the similar toxicological profile of the substances. 

In conclusion read-across for toxicological and eco-toxicological endpoints is considered valid without restrictions.