3,7-dimethyloctan-1-ol

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Additional information:

Limited information on skin sensitization is available for tetrahydrogeraniol from literature, being not suitable as key study. Therefore, data from structurally similar analogues were included for assessment of the sensitizing potential of tetrahydrogeraniol in a weight of evidence.

In the study on tetrahydrogeraniol, available from literature with limited documentation, i.e. an open epicutanous test in guinea pigs, 6-8 animals received 21 daily topical applications of tetrahydrogeraniol at a concentration at 8% to the shaved flanks (Klecak, 1979). The open, topical challenge applications were made on days 21 and 35 and the reactions were read at 24, 48 and 72 hours later. No sensitizing effects were detected under the chosen testing conditions.

In an human maximisation test avaliable from secondary source with limited documentation, tetrahydrogeraniol was tested at 8% in petrolatum and produced no sensitization reaction.

The structurally comparable substances i.e. isononanol, isodecanol, nonandiol, all share the same functional groups. Some belong to the group of the saturated branched chain alcohols and all substance cover the same and higher chain lengths. The structural analogue isononanol is a branched C9-alcohol with the same chain length, lacking a methyl group when compared to tetrahydrogeraniol. Isodecanol is a branched C10-alcohol with a longer chain length lacking a methyl group when compared to tetrahydrogeraniol. Nonandiol, lacks additional methyl groups and consists of two hydroxyl groups, therefore being putatively more reactive in regard to e.g. oxidation reactions when compared to tetrahydrogeraniol. Overall the chosen structural analogues cover a range of structural features including the features of tetrahydrogeraniol. 

In a Buehler skin sensitization study according to OECD guideline 406 under GLP, 20 female guinea-pigs received three occluded dermal induction applications and one similar challenge application of undiluted isononanol (BASF 2008; 32H0724/072158). The challenge with undiluted test substance did not cause any skin reactions neither in animals of the control group nor in test animals 24 and 48 hours after removal of the patches. Overall isononanol was found to be no skin sensitizer under the chosen testing conditions.

In a modified Draize test in Hartley strain albino guinea pigs, reported in literature with limited documentation, 10 animals were treated intradermally with 0.25% isodecanol for induction (Sharp 1978). For challenge isodecanol has been applied topically (10%) on one flank and intradermally (0.1%) on the other flank. As stated by the authors, isodecanol was found to be a non-sensitizer under the chosen testing conditions.

In a local lymph node assay similar to OECD guideline 429 und according to GLP , female CBA/JICO mice were treated at dose levels of 10, 30, and 60 % nonandiol in propylene glycol (BASF 2004; 45H01 83/032111). No statistical increase in lymph node cell counts and weights was observed. Therefore, nonandiol was found to cause no skin sensitization under the given testing conditions.

In summary, none of the studies analyzing tetrahydrogeraniol or its structural analogues showed any indication of a skin sensitizing potential. Therefore in a weight of evidence, tetrahydrogeraniol is not considered to be a skin sensitizer.

Respiratory sensitisation

Endpoint conclusion

Additional information:

No data available.

Justification for classification or non-classification

Based on the given data, a non-classification for skin sensitization according to the criteria of EU Directive 67/548/EEC and EU Regulations No 1272/2008 is warranted.