Phosphoric acid, C16-18-alkyl esters, potassium salts

Short-term toxicity to aquatic invertebrates

Description of key information

Study was conducted according to OECD guideline 202, data are reliable without restrictions.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

In a 48-h acute toxicity study, Daphnia magna were exposed to the read-across substance 1-Octadecanol, phosphate, potassium salt 

at concentrations of 0 and 100.0 mg/L nominal (WAF of 100 mg/L) under static conditions.

No significant effects on immobilisation of Daphnia magna were observed up to and including the highest test concentration (WAF of 100 mg/L 1-Octadecanol, phosphate, potassium salt).

EC50: > 100 mg/L (nominal)

NOEC:≥100 mg/L (nominal)

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.