Reaction mass of 2,6-Octadien-1-ol, 3,7-dimethyl-, (E) and 2,6-Octadien-1-ol, 3,7-dimethyl-, (Z)-

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Effect on fertility: via oral route

Dose descriptor:

NOAEL

1 000 mg/kg bw/day

Effect on fertility: via dermal route

Dose descriptor:

NOAEL

300 mg/kg bw/day

Additional information

A study according to OECD 421 using the oral route of exposure was performed with the reaction mass of geraniol and nerol (E- and Z-isomer, 60:40 -mixture) (BASF SE, 2010).

The test substance was administered to groups of 10 male and 10 female young Wistar rats dissolved in corn oil, via daily gavage. The dose levels were 0, 100, 300 and 1000 mg/kg body weight/day. About 2 weeks after the beginning of treatment, animals were mated to produce a litter. Mating pairs were from the same dose group. Pregnant females were allowed to give birth and the offspring was brought up until postnatal day (PND) 4. The study was terminated with the sacrifice of the pups on PND 4 and of lactating dams shortly thereafter.

All mid- and high-dose as well as some low-dose animals of both sex showed transient salivation for a few minutes immediately after each treatment. This was likely to be induced by the unpleasant taste of the test substance or by local irritation of the upper digestive tract. It is neither considered to be a sign of systemic toxicity nor as adverse.

Clinical observations indicated distinct toxicity in the exposed parental animals of the high dose group (1000 mg/kg bw/d) but not in the animals of the mid- and low-dose group.

A reduction of food consumption (up to 10% in males and females during treatment weeks 0-1 as well as females (-34%) during lactation), and decreased body weight in males (up to -5%) had been determined during treatment weeks 2-4. A similar pattern as for clinical observations was noted for body weight and body weight change of the parental animals. A distinct decrease was noted in the high-dose animals of both sex even manifested in different time periods of the study. The body weight change in males was reduced from week 0 to 5 (-28% on average in this time period). In females a significant body weight change was observed during lactation leading to a body weight loss (-3%). Consequently, the body weight was decreased in males during treatment weeks 2-5 (-7%) and in females of week 6 (-9%).

The test compound did not adversely affect fertility of the F0 generation parental animals at all dose levels as there were no changes of male/female mating and fertility indices, time until successful copulation, duration of pregnancy and mean number of implantations.

Hence, the respective NOAEL for fertility is 1000 mg/kg bw/day for the reaction mass of geraniol and nerol, whereas the NOAEL for systemic effects is lower. 

 

Apart from studies with the registered substance reaction mass of geraniol and nerol (E- and Z-isomer, 60:40 -mixture), studies using the pure test substance geraniol were taken into account to address the endpoint of toxicity to reproduction.

According to Cadby et al. (Consumer Exposure to Fragrance Ingredients: Providing Estimates for Safety Evaluation, Regulatory Toxicology and Pharmacology 36, 246–252 (2002)) the dermal route is the most relevant of systemic exposure to fragrance materials. "Safety evaluation of fragrance ingredients is based on data from tests, in which material is administered to human or animal subjects by placing it on the surface of the skin. For this reason, it is unnecessary to consider anything further than estimating quantities of these ingredients deposited on the surface of the skin." For this reason and according to REACh-Annexes ("most appropriate route of administration, having regard to the likely route of human exposure") a dermal reproduction / developmental toxicity screening test according to OECD 421 has been performed with purified geraniol in wistar rats (BASF SE, 2010).

A10 day range finding study with 3 female rats per dose using doses of 1000, 750, 500 and 300 mg/kg bw/day led to different grades of skin irritation (scales and erythema) in the doses of 500 - 1000 mg/kg bw/d, and no clinical findings of the treated skin in the 300 mg/kg bw/day group. Based on these findings, doses of 0, 50, 150 and 450 mg/kg bw/day were chosen for the reproduction screening study. The test substance was administered to 10 male and 10 female young Wistar rats dissolved in corn oil. Application area was the intact clipped skin of the back (dorsal and dorsolateral areas of the trunk; not less than 10% of the body surface). The first clipping was carried out at least 24 hours before the randomization. The rats were reclipped at least once a week (depending on the hair growth). Dermal application of the test-substance preparations to the clipped intact dorsal skin was carried out with 3-mL syringes and a semiocclusive dressing (4 layers of absorbent gauze and stretch bandage). The test-substance preparation was applied to the dorsal skin with the syringe in each case. After removal of the dressing, the application area was washed with lukewarm water. Application was daily for at least six hours.

During the course of the study the initial high dose (450 mg/kg bw/day) turned out to be intolerable for the rat skin (strong irritation reactions), so that from day 10 onwards the high dose had to be reduced to 300 mg/kg bw/day. About 2 weeks after the beginning of treatment, animals were mated to produce a litter. Mating pairs were from the same dose group. Pregnant females were allowed to give birth and the offspring was brought up until postnatal day (PND) 4. The study was terminated with the sacrifice of the pups on PND 4 and of lactating dams shortly thereafter.

Regarding clinical examinations, only signs of local dermal toxicity were observed for males and females at all dose levels. No changes in food consumption and body weight data were seen at any dose level.

Fertility indices for male and female animals were not impaired by test-substance administration.

Regarding pathology, there were no treatment-related necropsies or histological findings in ovaries, testes or epididymides associated with dermal administration of the test substance. The local minimal inflammatory reactions in the skin of treated males (test groups 1-3) and females (test group 3 only) were regarded as related to treatment and adverse.

Therefore, the NOAEL for fertility for geraniol is shown to be >300 mg/kg bw/day via the dermal route. Systemic exposure to geraniol is limited by the strong local irritation effects.

Waiving of an extended one-generation reproductive toxicity study (test method: OECD 443):

Based on the existing information in a Weight-of-Evidence approach, the absence of a classification as Category 1 for CMR properties and the analogy between reaction mass of Geraniol and Nerol and the pure substance Geraniol, adaptation rules acc. to REACH Annex XI are applied instead of conducting new studies.

In the past, the Registrant outlined an overall testing strategy covering both pure Geraniol (CAS No. 106-24-1, EC No. 203-377-1) and the related reaction mass of Geraniol and Nerol (EC No. 906-125-5) in his comments on ECHA’s draft decision (communication number: TPE-D-0000002211-91-05/F) and during the member state committee meeting on 23th October 2012. Animal testing in an extended one-generation reproductive toxicity study should only be performed on pure substances and not mixtures. Therefore, the Registrant has proposed to perform a one-generation reproductive toxicity study (OECD 443) in rats with pure Geraniol (CAS No. 106-24-1, EC No. 203-377-1) according to the following study design:

- Ten weeks premating exposure duration for the parental (P0) generation;

- Cohort 1A (Reproductive toxicity);

- Cohort 1B (Reproductive toxicity) without extension to mate the Cohort 1B animals to produce the F2 generation;

- Without Cohorts 2A and 2B (Developmental neurotoxicity) and

- Without Cohort 3 (Developmental immunotoxicity)

This testing proposal is listed on the ECHA web page “Current Testing Proposals”.Deadline for submitting information/comments is 11th December 2017.

Results obtained in the respective study with pure Geraniol can be taken into consideration in a Weight-of-Evidence approach for the reaction mass of Geraniol and Nerol in terms of classification and labelling. Results obtained with Geraniol and available data on reproductive toxicity on Nerol (disseminated dossier available) can be used to sufficiently cover the endpoint of reproductive toxicity for the reaction mass of Geraniol and Nerol and avoid additional further redundant testing on animals.

The submitted database shows, that the need of further studies is questionable. Furthermore, the exposure considerations demonstrated, that the conduction of a two-generation study is not justified from a risk based perspective. The systemic exposure of workers and the general population can be regarded as being negligible. Exposure of workers via the oral route is not expected and exposure leading to effective internal doses via the dermal or inhalative route is highly unlikely. Dermal exposure in an occupational setting is controlled and limited due to the use of closed systems and/or containment and personal protective equipment as industry standard. Inhalative exposure is limited due to the intense inherent odor which makes long term handling of the pure substance without any containment rather infeasible. Hence, exposure of workers to Geraniol 60 can be regarded as low. The RCR values reported in the CSR result from exposure estimations, that have generally been made using conservative exposure tools (e.g. ECETOC TRA) and/or assumptions, leading to an overestimation compared to the realistic exposure levels.

Much lower use levels of Geraniol 60 are found in formulated consumer products. Geraniol 60 exposure of the general population occurs due to the use as an ingredient in fragrance mixes and as flavor in trace amounts. For fragrance use, the dermal route represents the most relevant route, whereas inhalation appears to represent a minor route of systemic exposure to fragrances in general (Cadby 2002). The use levels of Geraniol 60 as component in fragrance mixes or as flavor are generally below 1% for REACH relevant consumer products (maximum use levels 1.5% in air care products).

As outlined above, an extended one-generation reproductive toxicity study (test method: OECD 443) in rats with the test substance reaction mass of 2,6-Octadien-1-ol, 3,7-dimethyl-, (E) and 2,6-Octadien-1-ol, 3,7-dimethyl-, (Z)-, does not need to be conducted. In order to avoid redundant testing and for animal welfare reasons, a tiered testing strategy based on a one-generation reproductive toxicity test using pure Geraniol in combination with the available data on reproductive toxicity on pure Nerol is considered appropriate.  

Short description of key information:
Toxicity to fertility:
- NOAEL: 1000 mg/kg bw/day (OECD 421, oral application)
- NOAEL: 300 mg/kg bw/day (OECD 421, dermal application, test substance: geraniol)

Effects on developmental toxicity

Description of key information

Developmental toxicity/teratogenicity
- NOAEL: 300 mg/kg bw/day

Effect on developmental toxicity: via oral route

Dose descriptor:

NOAEL

300 mg/kg bw/day

Additional information

Developmental toxicity was evaluated in a study performed according to OECD Guideline 414 (BASF SE, 2015). The test substance Geraniol 60 was administered as a solution in corn oil to 25 "time-mated" (mated by breeder) female Wistar rats/group by stomach tube at doses of 100, 300 and 1000 mg/kg bw on day 6 through day 19 post coitum (p.c.). On day 20 p.c., all females were sacrificed and assessed by gross pathology including the uterus and the placentae where corpora lutea were counted and number and distribution of implantation sites (differentiated as resorptions, live and dead fetuses) were determined. The fetuses were removed from the uterus, sexed, weighed, and further investigated for any external findings. Thereafter, nearly one half of the fetuses of each litter were examined for soft tissue findings and the remaining fetuses for skeletal findings.

As a result, administration of 1000 mg/kg bw elicited substance-induced effects on the dams including signs of maternal toxicity like reduced body weight gain on GD 6-8 (-53%) and GD 10-13 (-28%) resulting in about 10% less weight gain during treatment period (GD 6-19). The reduced corrected (net) body weight gain was about 14% below the concurrent control value. The dosage of 300 mg/kg bw/day resulted in reduced body weight gain on GD 6-8 (-43%) and reduced corrected (net) body weight gain about 13% below the concurrent control value. At the low dose (100 mg/kg bw/day) no substance-induced effects on dams occurred. The test substance had no influence on gestational parameters. Fetal examinations revealed that there is no effect of the compound on the respective morphological structures up to the highest dose tested (1000 mg/kg bw/d). Incidences of dilated renal pelvis and incomplete ossifications of various skeletal elements represent temporary delays in development which have no permanent effect on morphology and function of the affected organs or structures.

Based on these results, the no observed adverse effect level (NOAEL) for maternal toxicity is 100 mg/kg bw/day. The NOAEL for prenatal developmental toxicity could be fixed at 300 mg/kg bw/day.

 

An oral screening study according to OECD 421 and GLP with the reaction mass of Geraniol and Nerol (Geraniol 60) (BASF SE, 2010) showed effects on pup survival. The dose levels were 0, 100, 300 and 1000 mg/kg body weight/day. About 2 weeks after the beginning of treatment, animals were mated to produce a litter. Mating pairs were from the same dose group. Pregnant females were allowed to give birth and the offspring was brought up until postnatal day (PND) 4. The study was terminated with the sacrifice of the pups on PND 4 and of lactating dams shortly thereafter.

Pregnancy was unaffected at the low-dose. However, there is an alert for a dose-dependent adverse effect of the test substance on pre-/postnatal development of the F1 offspring at mid and high-dose level (300 and 1000 mg/kg bw/d). For the high-dose a lower live birth index (89 %) was noted. Pup survival until PND 4 was decreased by 25% and average pup body weight on PND 4 was decreased by 18%. This reduced live birth index was due to losses in only one animal in the group (all others showed no losses). The significantly reduced postnatal offspring weight/weight gain during the first 4 days after birth are likely related to maternal toxicity and ability to care and nurse for the pups as evidenced by clinical observations, empty stomachs in 10% of pups and significantly reduced feed consumption and body weights during the lactation period. Overall, it may be considered that the pup effects seen are secondary to maternal toxicity which effects pup care and nursing.

At the mid dose level, the same effects were noted, but at a lesser incidence and no significant effect on weight/weight gain was observed. The mid-dose also had a lower live birth index (94%). The slightly higher (non-significant) number of stillborns may well be contributed to the greater litter size in this group, which leaves the adverse effects on development of offspring in the mid-dose group to be limited to a slightly reduced pup survival (-9%). At least partially, the reduced pup survival may be secondary to a disturbance of maternal care as it became obvious by empty stomachs in pups which have been observed in 5% of mid-dose. In addition, findings in the mid dose appear to be limited to one animal. This animal appears to have maternal toxicity issues as evidenced by clinical observations (pups not properly nursed and insufficient maternal care of the pups), significantly reduced feed consumption and empty stomachs in the pups. These effects are similar to those seen at the top dose and it may therefore be concluded that maternal toxicity in this one animal is also responsible for the effects seen. The findings in this one animal appear to be an outlier in this group and excluding this animal from the data would show no significant findings vs. controls.

No such findings were noted at the low-dose.

Overall, maternal toxicity as evidence by lack of care of the pups, significantly reduced feed consumption in the dams and empty stomachs in the pups appears to be responsible for the findings seen at the top and mid dose groups. Effects are mainly due to one animal each at either dose group. The observed findings show a questionable correlation between the effects seen on maternal toxicity and effects seen on the offspring. Hence, their relevance based only on this screening study is doubtful and more complete studies at tolerated doses are required. Based on the present data, the NOAEL for developmental toxicity was set to 100 mg/kg bw/day.

 

In contrast, no such effects were seen in the dermal screening study described above (BASF SE, 2010). 10 young male and female Wistar rats per dose (0, 50, 150 and 300 mg/kg bw/day) were treated daily with Geraniol dissolved in corn oil for at least six hours on the clipped intact dorsal skin (semiocclusive dressing). About 2 weeks after the beginning of treatment, animals were mated to produce a litter. Mating pairs were from the same dose group. Treatment of the dams was discontinued from GD 20 onwards. Pregnant females were allowed to give birth and the offspring was brought up until postnatal day (PND) 4. The study was terminated with the sacrifice of the pups on PND 4 and of lactating dams shortly thereafter.

The live birth indices as well as the rate of stillborn pups was comparable between all test groups and the control and reflected the normal range of biological variation inherent in this strain. None of the pups died during lactation in the control group and in all test groups. F1 pups did not show adverse clinical signs up to scheduled sacrifice.

Therefore, for purified Geraniol also the NOAEL for developmental toxicity / teratogenicity is shown to be >300 mg/kg bw/day via the dermal route.

Justification for classification or non-classification

Untill further clarification is provided, no classification according to Directive 67/548/EEC and to Regulation (EC) No 1272/2008 is proposed.