Reaction mass of 4-isopropylidene-1-methylcyclohexene and 1-isopropyl-4-methyl-7-oxabicyclo[2.2.1]heptane and 1,3,3-trimethyl-2-oxabicyclo[2.2.2]octane

Endpoint summary

Description of key information

In an in vitro irritation study on human reconstructed epidermis model according to the OECD Guideline 439 and in compliance with GLP, mean relative cell viability for Terpinolene multiconstituent was 63.5 ± 5.4 %. 
In a BCOP test performed according to OECD 437, Terpinolene multiconstituent was negative. In an in vitro eye irritation study on human reconstructed corneal epithelium model, the exposure time that caused 50% of cell mortality was 42.88 min.

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:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

In an in vitro skin irritation study performed according to the OECD Guideline 439 and in compliance with GLP, 10 µL of Terpinolene multiconstituent was applied topically to reconstructed human epidermis model (3 epidermis units/dose) for 15 ± 0.5 min at room temperature. Cell viability was assessed with MTT. Mean relative cell viability for the test item was 63.5 ± 5.4 %.

In an in vitro eye irritation study performed in compliance with GLP, 30 µL of Terpinolene multiconstituent was applied to the human reconstructed corneal epithelium model (in duplicate) for 10 ± 2 min, 1 h ± 10 min and 3 h ± 30 min at room temperature. Contact timepoint for negative control (sodium chloride 0.9 % w/v) was 3 h ± 30 min and 10 ± 2 min and 1 h ± 10 min for positive control (SDS 1.5% w/w). At the end of each incubation period, each epithelium was rinsed, transferred to new well containing MTT solution and incubated for 1 h ± 10 min in CO2 incubator. Each epithelium was then transferred into a new well plate containing isopropanol (1 mL). After agitating for 1 h ± 10 min, the extract (200 μL/well) was transferred into a 96 wells microplate and optical density was recorded at 570 nm with a plates reader. For each treated tissue the viability was expressed as mean percentage of cellular viability relative to the negative control and the exposure time that causes 50% of cell mortality (T50) was determined by linear regression analysis. T50 value for the test item was 42.88 min. Optical density value for the negative control was 1.152 and T50 value for positive control was 33.49 min and thus confirmed the validity of the test.

Justification for selection of skin irritation / corrosion endpoint:
Only one study available for this endpoint.

Justification for selection of eye irritation endpoint:
Only study assessing the irritant potential of the substance.

Effects on eye irritation: moderately irritating

Justification for classification or non-classification

In an in vitro skin irritation study performed according to the OECD Guideline 439 and in compliance with GLP, cell viability was > 50 % on reconstructed human epidermis model therefore Terpinolene multiconstituent does not need to be classified for skin irritation according to the Directive 67/548/EEC and CLP Regulation (EC) N° (1272-2008).

In an in vitro eye irritation study on human reconstructed corneal epithelium model, the exposure time that caused 50% of cell mortality (T50) was 42.88 min. The T50 value of Terpinolene multiconstituent was between 10 and 60 min therefore it was considered as moderately irritant when applied on a human reconstructed corneal epithelium. Without clear correspondance between this test and common classification criteria, a conservative approach was adopted and Terpinolene multiconstituent was classified as irritant to eyes according to the Directive 67/548/EEC and CLP Regulation (EC) N° (1272-2008).