Fatty acids, C16-18 (even numbered), aluminum salts

Endpoint summary

Description of key information

Skin irritation (OECD 439): not irritating
Eye irritation (OECD 405): not irritating

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:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin irritation/corrosion

To assess the potential of Fatty acids, C16-18 (even numbered), aluminum salts to induce skin corrosion, an in vitro skin corrosion test was conducted according to OECD 431 (Lehmeier, 2012a). 25 mg of the test item were applied topically on EpiDerm^TM human skin equivalents (MatTek Corporation, Ashland, USA) after moistening the test item with 25 µL distilled water. After 3 or 60 min exposure, viability measurements revealed relative tissue viabilities of 90% and 114%, respectively. In contrast, the positive control substance KOH (8N) reduced the relative tissue cell viability to 17% and 9% after 3 or 60 min exposure, respectively, thereby validating the study. Thus, Fatty acids, C16-18 (even numbered), aluminum salts is considered to be non-corrosive to skin.

Further, an in vitro skin irritation test was performed according to OECD 439 (Lehmeier, 2012b). After moistening the test substance with 5 µL water, 10 mg were topically applied to intact reconstructed human epidermis (SkinEthic, Lyon, France) for 15 minutes prior to gentle washing with phosphate buffered saline. Concurrent control tissues were treated with phosphate buffered saline or 5% sodium dodecyl sulfate in parallel. After the post-incubation period of 42 h, MTT measurements revealed relative cell viabilities of test substance-treated tissues of 107% compared to the negative controls whereas a reduced relative cell viability of 7% was determined for the respective positive control tissues. According to the evaluation criteria given in OECD 439, Fatty acids, C16-18 (even numbered), aluminum salts is considered to be non-irritating to skin.  

Eye irritation

The eye irritation potential of Fatty acids, C16-18 (even numbered), aluminum salts was evaluated in a sequential testing strategy including a validatedin vitro eye corrosion/irritation test prior to in vivo testing as outlined in the OECD test guideline 405 for eye corrosion/irritation. An in vitro bovine corneal opacitiy and permeability test according to OECD 437 was performed (Lütkenhaus, 2012). Corneas were exposed to the test item or control substances (physiological saline (0.9%) and 20% imidazole as negative or positive control substance, respectively) in the closed-chamber method. 750 µL of the test item solution were introduced in the anterior chamber of the corneal holders for 4 h. Subsequent measurements after rinsing revealed a mean opacity value of 1.33 and a mean permeability value of -0.001 resulting in an in vitro irritancy score (IVIS) of 1.32. Positive control corneas reached an IVIS of 216.51 (opacity value: 188.0; permeability value: 1.901), thereby validating the study. According to the evaluation criteria given in OECD 437, the conductedin vitro test identified Fatty acids, C16-18 (even numbered), aluminum salts as non-corrosive.

In a GLP-guideline study performed according to OECD guideline 405, 3 female New Zealand White Rabbits were treated with 0.1 g test material without washing (Lütkenhaus, 2013b). The test item induced conjunctival redness grade 1 which was fully reversible latest after 72 h. No effects on the iris or cornea were observed in any test animal. Discharge of grade 2 or 3 was observed 1 h after test item instillation in all test animals which might be due to the instillation of a solid powder into the eyes. No mortality or clinical signs of toxicity were observed up to the end of the observation period. Based on the effects observed, Fatty acids, C16-18 (even numbered), aluminum salts, is not irritating to the eyes.

Justification for selection of skin irritation / corrosion endpoint:
The selected study is the most adequate and reliable study with significance for hazard identification of irritant chemicals in accordance with UN GHS and EU CLP Category 2 or “No Category".

Justification for selection of eye irritation endpoint:
The selected study is the most adequate and reliable study with significance for hazard identification.

Justification for classification or non-classification

The available data on skin or eye irritation do not meet the classification criteria according to Regulation (EC) 1272/2008 or Directive 67/548/EEC, and are therefore conclusive but not sufficient for classification.