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

Endpoint summary

Description of key information

Skin irritation: Terpinyl Acetate multi is not a skin irritation, based on read across with Terpinyl acetate alpha, which was tested in OECD TG 404.

Eye irritation: Terpinyl Acetate multi is not eye irritating, based on read across with Terpinyl acetate alpha, which was tested in OECD TG 438.

Respiratory irritation: The substance is not expected to be a respiratory irritant based on absence of skin and eye irritation.

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Additional information

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

Skin irritation / corrosion alpha-Terpinyl Acetate

Four in vivo skin irritation tests according to the OECD TG 404 have been performed. Three of these have been reported in ECETOC (1995) and one is performed by the Toxicol Lab. In ECETOC report, three primary dermal irritation tests are presented. These are performed according to OECD guideline 404 and in compliance with GLP, three (test 1) or four (test 2 and 3) albino rabbits were dermally exposed to 0.5 mL of undiluted alpha-Terpinyl Acetate under a semi-occlusive patch for 4 hours to intact skin of the flank (ECETOC 1995). Animals were then observed for 7 days. Irritation was scored by the method of Draize at 1, 24, 48 and 72 hours and 7 days after exposure. Mean individual scores at 24, 48 and 72 h after exposure for the 3 animals of the first test were 1.66, 2 and 2 for erythema score and 1, 2 and 2 for edema score. For the second test the mean individual scores were 2, 2, 2 and 2 for erythema score and 3, 2, 2 and 2 for edema score. For the third test the mean individual scores were 2, 1.67, 2 and 1,33 for erythema score and 2, 1, 0.67 and 0.33 for edema score.Under the test conditions the substance is not considered to be irritating to the skin because the scores are not >=2.3. At the end of the observation period of 7 days, reversibility of the effects were seen but in some animals slight desquamation was visible.

In the skin irritation study by the Toxicol Lab four albino rabbits were dermally exposed to 0.5 mL of undiluted alpha-Terpinyl Acetate, under a semi-occlusive patch for 4 hours to the clipped skin of the trunk (Hayes 1986). Animals were then observed for 7 days. Erythema and oedema was scored at 1, 24, 48 and 72 hours and 7 days after exposure. Erythema and edema scores of all animals were below 2.3. Seven days after dosing very slight reaction remained in three animals and desquamation from the surface of the treated skin was apparent in all four rabbits. In this study, alpha-Terpinyl Acetate was found not to be skin irritant when applied topically to the rabbit.

Eye irritation of alpha-Terpinyl Acetate

In a GLP compliant isolated chicken eye test performed according to OECD guideline 438, the eye irritation potential of alpha-Terpinyl Acetate was evaluated (TNO Triskelion 2012). Isolated chicken eyes were exposed to a single application of 30 uL of the test sample for 10 seconds followed by a 20 ml saline rinse. Three main parameters were measured to disclose possible adverse eye effects: corneal thickness (expressed as corneal swelling), corneal opacity and fluorescein retention of damaged epithelial cells. Alpha-Terpinyl Acetate caused very slight swelling of the cornea, slight or slight to moderate corneal opacity, and very slight or slight fluorescein retention. The calculated lrritation lndex was 42 (max possible score is 200). The negative control (saline) caused no corneal effects. The positive control BAC 5% caused moderate corneal swelling, severe opacity and severe fluorescein retention. The calculated lrritation lndex was 42 (max possible score is 200). According to the UN-GHS and the EU-CLP classification schemes of the lCE, alpha-Terpinyl Acetate is considered to be "Not Classified".

Respiratory irritation of alpha-Terpinyl Acetate and for Terpinyl Acetate multi

For respiratory irritation mostly human data are used for the assessment because no suitable in vitro or in vivo tests are available that can identify respiratory irritation (REACH guidance R.7.2.3). There are no human data such as indicated in R7.2.3 of the ECHA guidance that indicate respiratory reactions of the substance e.g. from consumer experience or occupational exposure. The substance is not a skin or eye irritant which further minimizes the respiratory irritation hazard (REACH guidance: 7.2.1.2).

Read across justification for Terpinyl Acetate multi from Terpinyl Acetate alpha for skin and eye irritation

Alpha-Terpinyl Acetate was tested in skin and eye irritation test according to OECD TG 404 and 438, which 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 constituents are all isomers and have the tertiary acetate as functional group. Based on this they have similar absorption in skin and eye tissues and also the reactivity is therefore expected the same. Therefore the absence of skin and eye irritation of alpha-Terpinyl Acetate can be used for gamma-Terpinyl Acetate.

Table 1: The constituents and impurities of alpha-Terpinyl Acetate and Terpineol Acetate multi

Terpinoids %	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	20777 -47 -3	Generic 59632-85-8
Alpha-Terpinyl Acetate	87	9	1	1
Terpinyl Acetate multi	64	20	7	4

 

Justification for classification or non-classification

Since in the skin irritation studies with alpha-Terpinyl Acetate no animals scored erythema >=2.3 and only two animals oedema of >= 2.3, CLP labelling is not needed. The slight irritation effects seen at the end of the observation period of 7 days indicate reversibility and are therefore not considered for classification and labelling because it can be anticipated that these effects are fully reversible within 14 days. These effects and the desquamation seen at the end of the test do not indicate effects needed for classification. The effects seen result in absence of classification and labelling according to the EU CLP (EC, 1272/2008 and its amendments).

The in vitro eye irritation study with alpha-Terpinyl Acetate showed minor eye irritation which does not warrant classification according to the EU CLP (EC, 1272/2008 and its amendments).

The absence of skin and eye irritation potential shows that Terpinyl Acetate multi is not corrosive or severely irritating which minimizes the respiratory hazard (REACH guidance: 7.2.1.2). Therefore, classification for respiratory irritation is not warranted.