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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:

The skin sensitisation potential of the Reaction mass of lithium 3-hydroxy-2,2,4-trimethylpentanoate and lithium isobutyrate and sodium 3-hydroxy-2,2,4-trimethylpentanoate and sodium isobutyratewas investigated in a skin sensitisation study conducted according to OECD Test Guideline 429 using the local lymph node assay (Valiczko, 2013). In the study, a Preliminary Irritation /toxicity test was carried out in which CBA/J Rj mice were treated with the test substance, sodium isobutyrate solution, at 50% or 100% w/v in 1 % Pluronic. On the basis of this test, 100% w/v was selected as the top dose for the main assay.

In the main assay, twenty female CBA/J Rj mice were allocated into five groups of four: three groups were treated with the test substance (formulated in 1% Pluronic) at 25, 50 and 100% w/v; the negative control group received the vehicle (1% Pluronic) and the positive control group received 25% w/v α-Hexylcinnamaldehyde (HCA) dissolved in 1% Pluronic. The test item solutions were applied on the dorsal surface of the ears of mice at 25 μL/ear for three consecutive days (Days 1, 2 and 3), with no treatment being administered on Days 4,5 and 6. On day 6, the cell proliferation in the local lymph nodes and the results were used to calculate stimulation indices (SI).  

No mortalities or systemic clinical signs were observed during the study. The observed stimulation index values were 1.5, 1.9 and 0.9 at concentrations of 100, 50 and 25% (w/v) respectively. Under the conditions of this study, treatment with sodium isobutyrate solution at concentrations up to 100% did not cause skin sensitisation. On this basis, the Reaction mass of lithium 3-hydroxy-2,2,4-trimethylpentanoate and lithium isobutyrate and sodium 3-hydroxy-2,2,4-trimethylpentanoate and sodium isobutyrateis not a skin sensitiser.

There is no indication from the experience of use that this substance can cause skin sensitisation in exposed workers.


Migrated from Short description of key information:
The Reaction mass of lithium 3-hydroxy-2,2,4-trimethylpentanoate and lithium isobutyrate and sodium 3-hydroxy-2,2,4-trimethylpentanoate and sodium isobutyrate was not found to cause skin sensitisation in a study conducted using the local lymph node assay. There is no evidence from the experience of use that the substance has the potential to cause skin or respiratory sensitisation in exposed workers.

Justification for selection of skin sensitisation endpoint:
Sole study providing data from a guideline compliant study. Under the conditions of the study, the test substance was not found to be a skin sensitiser.

Respiratory sensitisation

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

There is no indication from the experience of use that the Reaction mass of lithium 3-hydroxy-2,2,4-trimethylpentanoate and lithium isobutyrate and sodium 3-hydroxy-2,2,4-trimethylpentanoate and sodium isobutyratecan cause respiratory sensitisation in exposed workers.


Migrated from Short description of key information:
There is no indication from the experience of use that the Reaction mass of lithium 3-hydroxy-2,2,4-trimethylpentanoate and lithium isobutyrate and sodium 3-hydroxy-2,2,4-trimethylpentanoate and sodium isobutyrate can cause respiratory sensitisation in exposed workers.

Justification for selection of respiratory sensitisation endpoint:
There is no indication from reports in exposed workers that the substance can cause respiratory sensitisation (occupational asthma).

Justification for classification or non-classification

The Reaction mass of lithium 3-hydroxy-2,2,4-trimethylpentanoate and lithium isobutyrate and sodium 3-hydroxy-2,2,4-trimethylpentanoate and sodium isobutyratedid not cause skin sensitisation in a study conducted using the local lymph node assay. The substance does not meet the criteria for classification for skin or respiratory sensitisation according to Directive 67/548/EEC or Regulation 1272/2008/EC.

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