Barium 3,5,5-trimethylhexanoate

Endpoint summary

Description of key information

No skin sensitisation study with barium bis(3,5,5-trimethylhexanoate) is available, thus the skin sensitisation potential will be addressed with existing data on the assessment entities barium and 3,5,5-trimethylhexanoic acid. According to the RAAF, neodecanoic acid will be considered in place of 3,5,5-trimethylhexanoic acid.

Barium bis(3,5,5-trimethylhexanoate) is not expected to show signs of dermal sensitisation, since the two assessment entities barium and 3,5,5-trimethylhexanoic acid, as represented by neodecanoic acid, 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:

No skin sensitisation study with barium bis(3,5,5-trimethylhexanoate) is available, thus the skin sensitisation potential will be addressed with existing data on the individual moieties barium and 3,5,5-trimethylhexanoic acid. According to the RAAF, neodecanoic acid will be considered in place of 3,5,5-trimethylhexanoic acid.

Barium

The reference Stitzinger (2010) is considered as the key study on skin sensitisation and will be used for classification. The overall sensitisation results are as follows: Local lymph node assay (LLNA) in mice SIs of less than 3.0 (1.2 – 1.5) were observed at all test concentrations of barium dichloride dihydrate (5, 10, 25 %) and no dose response could be observed. Therefore, an EC3 value (the estimated concentration required to induce a threshold positive response, i.e., SI = 3) for the test substance under the conditions of the study was not calculable.

Neodecanoic acid

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.   

 

Barium bis(3,5,5-trimethylhexanoate)

Barium bis(3,5,5-trimethylhexanoate) is not expected to show signs of dermal sensitisation, since the two assessment entities barium and 3,5,5-trimethylhexanoic acid, as represented by neodecanoic acid, have not shown any skin sensitisation potential in experimental testing. Thus, barium bis(3,5,5-trimethylhexanoate) 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

Barium bis(3,5,5-trimethylhexanoate) is not expected to show signs of dermal sensitisation, since the two moieties barium and 3,5,5-trimethylhexanoic acid, as represented by neodecanoic acid, have not shown any skin sensitisation potential in experimental testing and occupational exposure. Thus, barium bis(3,5,5-trimethylhexanoate) is not to be classified according to regulation (EC) 1272/2008 as skin sensitising.