3,7-dimethyloctan-3-ol

Endpoint summary

Additional information

Skin irritation

Tetrahydrolinalool was investigated for its skin irritation potential in vitro and in vivo.

In an internal BASF test, the substance was applied for 1 min, 5 min, 15 min, and 20 hours undiluted on the skin of 2 rabbits under occlusive conditions (BASFAG XXVI402). In this experiment the substance produced a slight reddening, visible 24 h after application in one animal already after a skin contact of 1 min and 5 min. When applied for 15 min, clearly visible reddening and reversible desquamation could be observed in both animals. After an application time of 20 hours, the animals showed moderate to strong erythema with slight to moderate edema formation both exceeding the area of application and an irreversible desquamation at the end of the study period (8 days). Mean erythema and edema scores (24 h, 48 h observation time point; 2 animals) was 2.5 and 2 respectively after the 20 hour occlusive test substance application. In contrast to the current OECD test guideline, the BASF test was done under occlusive (vs semiocclusive) conditions for 20 hours (vs. 4 hours). Therefore, test conditions used in this test have to be considered more stringent compared to todays standard protocols, representing a worst case scenario. On the basis of this study, a hazard concerning skin corrosion can be excluded for tetrahydrolinalool.

In an in vitro study, i.e. EpiDerm^TMSkin Irritation Test (according to the OECD Draft Proposal for a New Guideline on In Vitro Skin Irritation: Human Skin Model Test of 06-Jun-2008 and GLP) , undiluted tetrahydrolinalool caused a mean tissue viability < 50% of the respective controls (BASF61V0267/10A113). Therefore, tetrahydrolinalool shows a skin irritation potential in the EpiDermTM skin irritation test under the test conditions chosen and confirms the findings from the in vivo data.

In an acute dermal toxicity study, available as short summary from a secondary source, moderate erythema and edema were reported after topical (occlusive) application on 10 rabbits (1976).

Taken together in a weight of evidence, tetrahydrolinalool was found to be irritative to the skin.

In a pre-test for a maximization study, beeing available as short summary from a secondary source, a 48-hour closed patch test was conducted on 32 healthy volunteers using 4% tetrahydrolinalool in petrolatum (Epstein 1976). No dermal irritation was observed, indicating the absence of dermal irritation potential at concentrations up to 4%.

Eye irritation

In the key study, a Draize test was performed with 2 White Vienna rabbits (BASFAG XXVI402). Eyes were left unwashed after application of 0.05 ml undiluted tetrahydrolinalool and the animals were observed for 8 days. The mean score (24 and 48 h reading; all animals) was 1.5 for conjunctiva redness; 0.75 for chemosis and 1.0 for corneal opacity. Iritis was not observed. Conjunctiva redness was not reversible at the end of the observation period of 8 days in both animals.

Irritant effects to the eye were also observed in a study, available as short references from secondary source, lacking further study details such as single animal irritation scores ( Melceva 1990).

Effect level: empty Endpoint conclusion: Adverse effect observed

Effect level: empty Endpoint conclusion: Adverse effect observed

Justification for classification or non-classification

Skin irritation

Taken together in a weight of evidence, the present data fulfill the criteria laid down in regulation (EC) 1272/2008, and a classification "skin irritant" (category 2) is warranted.

 

Eye irritation

Based on the mean scores (24 and 48 h reading; all animals), i.e. 1.0 for corneal opacity and the lack of reversibility of conjunctival redness after 8 days and according to regulation (EC) 1272/2008, a classification as "eye irritant" (Category 2A) is warranted.