Reaction mass of 1-methyl-4-(1-methylethylidene)cyclohexyl acetate and p-menth-1-en-8-yl acetate

Endpoint summary

Description of key information

Terpinyl Acetate multi is not a skin sensitiser based on information from Terpinyl Acetate alpha, which was tested in an LLNA (OECD TG 429) in which the SI remained below 3 when tested up to 100%.

The substance is not a respiratory sensitiser because it is not a skin sensitiser.

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

First the executive summary of the source is presented, thereafter the read across justification.

Skin sensitisation of alpha-Terpinyl Acetate

In a GLP compliant sensitisation study performed according to OECD guideline 429 the contact hypersensitivity of alpha-Terpinyl Acetate in the Mouse (Local Lymph Node Assay) was assessed (WILResearch 2012). Test substance concentrations selected for the main study were based on the results of a pre-screen test. In the main study, three experimental groups of five female CBA/J mice were treated with test substance concentrations of 25, 50 or 100% w/w on three consecutive days, by open application on the ears. Five vehicle control animals were similarly treated, but with vehicle alone (Acetone/Olive oil (4:1 v/v)). Three days after the last exposure, all animals were injected with 3H-methyl thymidine and after five hours the draining (auricular) lymph nodes were excised and pooled for each animal. After precipitating the DNA of the lymph node cells, radioactivity measurements were performed. The activity was expressed as the number of Disintegrations Per Minute (DPM) and a stimulation index (SI) was subsequently calculated for each group. The SI values calculated for the substance concentrations 25, 50 and 100% were 1.3, 2.2 and 2.4 respectively. Since there was no indication that the test substance elicits an SI ≥ 3 when tested up to 100% the substance is not a skin sensitiser and therefore Terpinyl Acetate multi is not a skin sensitiser either.

Read across justification for Terpinyl Acetate multi from Terpinyl Acetate alpha for skin sensitisation

Alpha-Terpinyl Acetate was tested in an LLNA and this information can be used for read across to Terpinyl Acetate multi. Firstly, this is because alpha-Terpinyl Acetate is the key constituent of Terpinyl Acetate multi as presented in the table below and covers more than 80% of Terpinyl Acetate alpha because the latter also contains impurities similar to the constituents of Terpinyl Acetate multi. The substances are isomers and have the tertiary acetate as the functional group. The substances have the same dermal absorption based on the physico-chemical properties. The reactivity is also considered the same based on similar reactive (terpenoid group). Therefore the absence of skin sensitisation of alpha-Terpinyl Acetate can be used for Terpinyl Acetate multi.

Table A: The constituents of alpha-Terpinyl Acetate, Terpineol Acetate multi

Terp-inoids	Alpha-Terpinyl Acetate (% Constituent)	Gamma-Terpinyl Acetate (% Constituent)	cis-beta- Terpinyl Acetate (% Impurity)	trans-beta Terpinyl Acetate (% Impurity)
Cas no.	80-26-2	10235-63-9	Generic 59632-85-8	Generic 59632-85-8
Alpha-Terpinyl Acetate	87	9	1	1
Terpinyl Acetate multi	64	20	7	6

 

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Respiratory sensitisation can be assessed using human data such as indicated in R7.3.5.2 of the ECHA guidance that indicate respiratory reactions e.g. from consumer experience or occupational exposure. In case no such data are available the respiratory sensitization can be assessed using the integrated evaluation strategy for respiratory sensitization data in the ECHA guidance (R7A, Fig. 7.3-2), which says that if the substance is a non skin sensitiser, than it is unlikely to be a respiratory sensitiser.

Justification for classification or non-classification

Based on the negative result of the available skin sensitisation study of alpha-Terpinyl Acetate being the main constituent of Terpinyl Acetate multi, classification for skin and respiratory sensitisation is not warranted according to EU CLP (EC No. 1272/2008 and its amendments).