Pentyl salicylate

Endpoint summary

Additional information

To address toxicological endpoints as part of the REACH registration of Amyl Salicylate (Target Substance) it is proposed to read-across to Cyclohexyl Salicylate (Source Substances).

The use of read-across works within the spirit of REACH and the stated aim of the legislation to reduce animal testing where possible.

The Target Substance and Source Substance have been characterised using the categories and databases present in the OECD [Q]SAR Toolbox. From the profiling, it can be seen that these substances share structural similarities and also ‘mechanistic action’ similarities which are both general and endpoint specific.

For classification and labelling purposes this indicates that the structural analogues are relatively harmless and would not be classified in accordance with Regulation (EC) No 1272/2008 (CLP). The registration substance is considered to have similar properties and is therefore not classified in accordance with CLP.

As discussed within the RAAF document:

The category justification includes a comparison of the experimental data for the 11 category members in a data matrix presented.

The summary of the data is below for ease of review.

Negative: In vitro assay = BlueScreen - 8 negative substances, Bacterial reverse mutation - 7 negative substances, Mammalian chromosome aberration - 4 negative substances.

Negative: In vivo = Mutagenicity (Micronucleus) - 2 negative substances.

BlueScreen Data:

It has been shown by Gentronix that the BlueScreen is highly predictive towards the standard test battery of Genetic Toxicology assays. This assay detects substances that are capable of causing damage to genetic material (DNA) within a cell and uses the human-derived, p53 competent, TK6 cell line to host a patented Gaussia  luciferase (GLuc) reporter system which exploits the proper regulation of the GADD45a gene. The “specificity” is currently 96% and the “sensitivity” is 87%.

The available fragrance industry data comparing BlueScreen data to the available experimental data for genetox, indicates that the “specificity”is 90%. This also therefore indicates that a negative result in the BlueScreen gives a very high probability that the subsequent genetox assay will also be negative.

The predicted “specificity”for the in vitro data for each in vitro assay increases when directly comparing the BlueScreen data with the in vitro test battery as shown below:

In vitro: Bacterial reverse mutation = 81%, Mammalian cell gene mutation = 92%, Mammalian Chromosome Aberration = 97%.

Eight of the category substances including the “target” substance (benzyl salicylate), have negative experimental BlueScreen data in the absence and presence of S9-mix. This therefore indicates that thein vitrogenetox battery of tests would also be negative.

In vitro bacterial Reverse Mutation Data:

The bacterial reverse mutation test (Ames test) is a core component of safety assessment testing battery and detects point mutations, involving substitution, addition or deletion of one or a few DNA base pairs.

As 7 of the category substances including the “target” substance (benzyl salicylate, have negative experimental Ames data, this indicates that although benzyl salicylate has an alert for DNA binding (OECD profile), this alert is not predictive of the actual DNA interaction within an in vitro test system.

Especially when taking into account the lack of DNA alerts based on the OASIS profiling. Therefore this indicates that all the category members would be negative in the in vitro Ames test. These experimental results are also in agreement with the BlueScreen data as previously shown above.

In vitro Mammalian Chromosome Aberration:

The mammalian chromosome aberration test is a core component of safety assessment testing battery and detects certain chromosome changes such as structural chromosome aberrations, breakages and numerical changes. 

As 4 of the category substances have negative experimental mammalian chromosome aberrationdata, this data alongside the BlueScreen experimental data, the Ames experimental data and the lack of DNA alerts (OECD [Q]SAR Toolbox - Ames, MN and CA by OASIS v.1.3.) for the 11 category members, this indicates that benzyl salicylate would also be predicted to negative in this in vitro test system.

In vivo Mutagenicity (Micronucleus):

Only 2 members of this category havein vivomutagenicity micronucleus data. However, all 11 of these substances have in vivo mutagenicity micronucleus alerts for H-acceptor-path3-H-acceptor interaction which indicates a possiblechemical interaction with DNA and/or proteins via non-covalent binding, such as DNA intercalation or groove-binding.

However, the results of the 2 main source substances both have negative experimental data for this endpoint and therefore it can be assumed that when taken into account with thein vitrodata and the experimental data consistencies (negative data) within the category and the total lack of any DNA interactions (in vitro and in vivo), that the target substance benzyl salicylate would also be negative in such a genetox in vivo micronucleus assay.

Short description of key information:
Ames test (Benzyl salicylate): non-mutagenic with and without S9
In vitro cytogenicity (chromosome aberration on Methyl salicylate): non-mutagenic with and without S9
In vitro gene mutation in mammalian cells: Data waived as reliable in vivo data on structural analogue is available.
In vivo Mouse micronucleus (2-ethylhexyl salicylate): did not induce chromosomal damage or damage to the mitotic apparatus in bone marrow cells of mice

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

For classification and labelling purposes this indicates that the Source Substances are suitable structural analogues and based on the response seen for the above end points the Target substance is considered not to be mutagenic. Classification and labelling is therefore not required.