3-Cyclohexene-1-methanol, α,4-dimethyl-α-(4-methyl-3-penten-1-yl)-

Endpoint summary

Description of key information

The oral LD50 value was determined > 2000 mg/kg body weight (acc. OECD TG 423, GLP; BASF 2001; 10A0588/001113).
The dermal LD50 was determined to be > 750 a.i. mg/kg bw (Symrise 1983) and > 5000 mg/kg bw (Moreno 1973)

Additional information

Acute oral toxicity:
In the chosen key study for acute oral toxicity according to OECD TG 423 and GLP , a single dose of 2000 mg/kg body weight of (-) alpha-Bisabolol (nat. roh; Candeia-Öl), i.e. a main component of registered substance racemic alpha-Bisabolol, in olive oil were given to two dose groups of three fasted animals, each (males and females) by gavage in a sequential manner (BASF 2001; 10A0588/001113). No mortality occurred. No clinical signs and findings were observed. The mean body weights of the dose groups increased throughout the study period. No macroscopic pathologic abnormalities were noted in the animals examined at the end of the observation period. The median lethal dose of the test substance after oral administration was found to be greater than 2000 mg/kg body weight for male and female rats.

Overall, (-) alpha-Bisabolol was found to be virtually non-toxic after single oral administration.

In a supportive study, single oral administration of 2150 and 5000 mg/kg bw (+/-) alpha-Bisabolol to 5 male and 5 female Sprague Dawley rats, respectively, resulted in no mortality and an LD50 > 5000 mg/kg has been determined (BASF 1980; 79/65).
Other studies not acc. to current guidelines using rodent (rat, mouse) and non-rodent (dog and rhesus monkeys) species confirmed the absence acute toxicity after single oral dosing of alpha-Bisabolol.

Overall, based on the given results, racemic (+/-) alpha-Bisabolol is considered to be virtually non-toxic after single oral administration.

Acute inhalation toxicity:

For the coverage of a second and human relevant route of exposure, a study on acute dermal toxicity is available. In accordance with column 2 of REACH Annex VIII, the study does not need to be conducted as studies with two other routes are provided. Furthermore, supportive evidence from an inhalation hazard test not according to current study protocols, does not indicate an acute inhalative toxicity hazard for (+/-) alpha-Bisabolol (BASF 1980; 79/65).

Acute dermal toxicity:
In an acute dermal toxicity study using two groups (scarified and intact skin) of 5 male and 5 female WISW rats, 5% (+/-) alpha Bisabolol in vaseline was applied dermally (occlusive) for 24 hours at a dose of 15000 mg/kg bw, i.e. 750 mg/kg bw active ingredient (Symrise 1983; 1 -4 -86 -83). Any signs of reaction were recorded during the 14-days observation period, animals that died and those killed terminally were subjected to necropsy. In the tested dosage the sample did not induce any clinical-toxicological symptoms. No skin alterations were observed. Post-dosing weight gains of all animals did not show essential differences. No mortalities were observed. Nothing abnormal was found in the animals necropsied an day 14. The dermal LD50 value was > 15000 mg/kg bw or > 750 mg/kg bw active ingredient.

In an acute dermal toxicity study in rabbits, reported from secondary source with limited documentation, Chamomile flower oil has been applied dermally (Moreno 1973). The LD50 has been reported to be > 5000 mg/kg bw.

Overall in a weight of evidence including acute dermal toxicity data and the absence of acute toxicity after single oral administration up to limit dose, racemic (+/-) alpha-Bisabolol is considered to be virtually non-toxic after single dermal application.

Justification for classification or non-classification

The present data on acute oral and dermal toxicity do not fulfill the criteria laid down in 67/548/EEC and regulation (EU) 1272/2008, and therefore, a non-classification is warranted.