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Description of key information

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

Read across BaCl2to Ba(OH)2:

No studies for determination the sensitisation properties of Ba(OH)2have been performed and none are proposed, based on scientific considerations and for animal welfare reasons. In accordance with column 2 of REACH Annex VII, the skin sensitisation study (required in section 8.3) does not need to be conducted since the available information indicates that the criteria are met for classification as corrosive to the skin (pH≥11.5).

However, the sensitisation potentialmay reasonably be considered to be determined by availability of Ba2+cations.As a first surrogate for bioavailability, the water solubility of a test substance may be used. A sensitisation study is made available for barium chloride. Barium chloride is highly water soluble with ca. 263 g/L at pH ca. 6.5 (510.4 g/L at pH 1.5). Also the water solubility of barium hydroxide is high (37.4 mg/L at pH > 13). Hence, any read across from barium chloride to barium hydroxide is considered to be justifies and will likely lead to rather conservative no-effect levels.


The LLNA study conducted with barium chloride causes no sensitising effects to skin. Due to barium hydroxide it can be stated that barium hydroxide as such has no sensitising potential.

Justification for classification or non-classification


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 chloride 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. Thus, the classification criteria acc. to regulation (EC) 1272/2008 as skin sensitizer are not met and barium chloride has not being labelled as such.