1-Octadecanol, phosphate, potassium salt

Endpoint summary

Description of key information

1-Octadecanol, phosphate, potassium salt is classified for eye irritation, but not for skin irritation

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin irritation:

In a primary dermal irritation study, New Zealand White were dermally exposed to Phosphoric acid, C16-18-alkyl esters, potassium salts (undiluted) to for 24 hours under an occlusive dressing to shaved and shaved and abraded skin areas.  Animals then were observed for 72 hours. Irritation was scored by the method of Draize.  

On shaved areas no irritation was observed in all animal whereas on the abraded areas in 4/6 animals erythema score 1 was observed at the 24 hour reading.Effects were reversible within 72 hours.

Eye irritation:

In a primary eye irritation study, albino rabbits were exposed to 1-Octadecanol, phosphate, potassium salt and observed until reversibility was achieved. Very well-defined signs of irritation were observed on the treated eyes. All effects were fully reversible within 7 days.

Justification for read-across:

Justification for selection of skin irritation / corrosion endpoint:
Reliable data from a read-across from an in-vivo study conducted similar to OECD guideline 404

Justification for selection of eye irritation endpoint:
Reliable data from a study study conducted accroding to OECD guideline 405 with GLP

Effects on eye irritation: irritating

Justification for classification or non-classification

Skin irritation:

No effects were observed in a primary irritation study with the read-across substance Phosphoric acid, C16-18-alkyl esters, potassium salts under and extended exposure of 24 hours and occlusive dressing.

According to CLP; EU GHS (Regulation (EC) No 1272/2008) and directive 67/548/EEC no classification is required for skin irritation.

 

Eye irritation:

In a study conducted according to OECD Guideline No. 405, very well-defined signs of irritation were observed on the treated eyes. All effects were fully reversible within 7 days.

Based on the respective mean conjunctivae scores of 2.67, 2 and 2 classification in category 2 is required according to CLP; EU GHS (Regulation (EC) No 1272/2008).

However, based on slight different threshold values no classification for eye irritation is required according to directive 67/548/EEC.

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.