Neodecanoic acid, zirconium salt

Endpoint summary

Description of key information

No skin sensitisation study with neodecanoic acid, zirconium salt is available, thus the skin sensitisation potential will be addressed with existing data on the assessment entities zirconium and neodecanoate. Neodecanoic acid, zirconium salt is not expected to show signs of dermal sensitisation, since the two moieties zirconium and neodecanoate have not shown any skin sensitisation potential in experimental testing.

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Zirconium

Two reliable in vivo tests are available for the skin sensitisation endpoint of zirconium compounds.

 

The potential of zirconium acetate solution (40.7% as zirconium acetate anhydrous), to cause skin sensitisation reactions following topical application to the skin of CBA/JN (CBA/J) mice, was assessed using the LLNA:BrdU-ELISA method, according to OECD Guideline for testing of chemicals no. 442b.

In the main sensitisation assay, the test item was administered at the concentrations of 100% (undiluted test item, not corrected for zirconium acetate concentration of 40.7% w/w), 50% and 25% w/w.

No increases in cell proliferation of draining lymph nodes were observed at any of the concentrations investigated. The calculated stimulation indices (SI) were 1.02, 1.06 and 0.72, respectively low, mid- and high dose levels.

The results obtained in this study indicate that the test item does not elicit any sensitisation response in mice following dermal exposure.

 

A second reliable (Klimisch 2) study was available for the skin sensitisation endpoint of zirconium dioxide. The traditional skin sensitisation test was performed according to OECD guideline 406 and the Maximization Test of the Guideline for Toxicity Studies of Drugs (Notification No. 1 -24 of Pharmaceuticals and Cosmetics Division dated September 11, 1989). Female Guinea pigs of the Hartley strain received following treatment:

Intradermal sensitisation

1) Test agent group - E-FCA (equal volume (v/v) of "distilled injection water" and Freund's complete adjuvant (FCA) were mixed and emulsified in water-in-oil style - 2.5% test agent - 2.5% test agent/FCA emulsion

2) Control group - E-FCA

3) Positive control group - E-FCA - 0.1% DNCB/olive oil - 0.1% DNCB/FCA emulsion

Patch sensitisation

1) Test agent group - 25% test agent

2) Control group - distilled injection water

3) Positive control group - 0.5% DNCB

Elicitation Treatment

1) Test group and control group - 25% test agent - 2.5% test agent

2) Positive control group - 0.1% DNCB

Zirconium dioxide was found to be not sensitising to the skin at level up to 25% whilst the positive control substance, DNCB, was found to have an extreme skin sensitising potential.

 

Neodecanoate

Neodecanoic acid has been examined for skin sensitization potential in the guinea pig maximization procedure of Magnusson and Kligman. Groups of ten male and ten female guinea pigs were used for the test and a further five males and five females as controls. Induction was accomplished in two stages. 

 1) Intradermal injection: Two rows of three injections were made, one on each side of the midline in the shorn skin of the shoulder region. 2) Topical application: One week after the intradermal injections, the same area was clipped free from hair. A 4x4 cm patch of filter paper was soaked in a solution of the test material and placed over the injection sites and covered with an occlusive dressing. The dressing was left in place for 48 hours. The challenge procedure was carried out two weeks after topical induction. Challenge was accomplished by topical application of the test material to the flank of animals via an occluded patch. The challenge lasted 24 hours. Immediately after the challenge, and then again at 24 and 48 hours later, each animal was examined for signs of skin sensitization. At no point was there any evidence of skin sensitization produced by neodecanoic acid.   

 

Neodecanoic acid, zirconium salt

Neodecanoic acid, zirconium salt is not expected to show signs of dermal sensitisation, since the two assessment entities zirconium and neodecanoate have not shown any skin sensitisation potential in experimental testing. Thus, neodecanoic acid, zirconium salt is not to be classified according to regulation (EC) 1272/2008 as skin sensitising. Further testing is not required. For further information on the toxicity of the individual assessment entities, please refer to the relevant sections in the IUCLID and CSR.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Neodecanoic acid, zirconium salt is not expected to show signs of dermal sensitisation, since the two assessment entities zirconium and neodecanoate have not shown any skin sensitisation potential in experimental testing. Thus, neodecanoic acid, zirconium salt is not to be classified according to regulation (EC) 1272/2008 as skin sensitising.