Registration Dossier

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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Key value for chemical safety assessment

Toxic effect type:
dose-dependent

Effects on fertility

Description of key information

Oral (rat, m/f, OECD 422): NOAEL (reproduction) = 1000 mg/kg bw/day

Oral (rat, m/f, OECD 422): NOAEL (systemic toxicity) = 1000 mg/kg bw/day

Oral (rat, m/f, OECD 422): NOAEL (local toxicity) = 1000 mg/kg bw/day

 

Read-across based on grouping of substances (category approach) considering all the available data on reproductive toxicity in the AE category, in a Weight-of-Evidence approach.

Link to relevant study records
Reference
Endpoint:
screening for reproductive / developmental toxicity
Type of information:
read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Justification for type of information:
Please refer to the category justification provided in the category object.
Key result
Dose descriptor:
NOAEL
Effect level:
>= 1 000 mg/kg bw/day (actual dose received)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: No toxicologically relevant effects observed
Key result
Critical effects observed:
no
Key result
Dose descriptor:
NOAEL
Generation:
F1
Effect level:
>= 1 000 mg/kg bw/day (actual dose received)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: No toxicologically relevant effects observed
Key result
Critical effects observed:
no
Key result
Reproductive effects observed:
no

For a detailed assessment of the reproductive / developmental toxicity of the Alcohol Ethoxylates (AE) category, please refer to the category justification attached to the category object.

Conclusions:
Applying read-across based on grouping of substances (category approach), no toxicologically relevant effects in relation to reproductive / developmental toxicity and a NOAEL for reproductive toxicity ≥ 1000 mg/kg bw/day are predicted for the registered substance.
Executive summary:

The available data on reproductive / developmental toxicity in the 'linear' subgroup of the Alcohol Ethoxylates (AE) category indicate no toxicologically relevant effects for the registered substance. As explained in the category justification, the differences in molecular structure and composition between the registered substance and the members of the AE category are unlikely to lead to differences with respect to reproductive / developmental toxicity.

Effect on fertility: via oral route
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEL
1 000 mg/kg bw/day
Study duration:
subacute
Species:
rat
Quality of whole database:
The available information comprises adequate and reliable (Klimisch score 1) studies from various source substances in the Alcohol Ethoxylates (AE) category with similar structures and intrinsic properties. Read-across is justified based on common toxicokinetic behaviour and consistent trends in environmental fate, ecotoxicological and toxicological properties of the category member substances. The data pool of the AE category is thus sufficient to fulfil the standard information requirements set out in Annexes VIII - X, Section 8.7, in accordance with Annex XI, Section 1.5, of the REACH Regulation (EC) No. 1907/2006.
Effect on fertility: via inhalation route
Endpoint conclusion:
no study available
Effect on fertility: via dermal route
Endpoint conclusion:
no study available
Additional information

No data on toxicity to reproduction are available for octadecan-1-ol, ethoxylated (CAS No. 9005-00-9, EC No. 500-017-8). In order to assess the potential for toxicity to reproduction, studies in the database of the Alcohol Ethoxylates (AE) category are considered in a read-across approach. Studies investigating toxicity to reproduction are available for the following AE substances (Table 1):

Table 1

CAS No.

EC No.

Substance

Screening study (OECD 422)

 

NOAEL reproduction/ fertility [mg/kg bw/day]

NOAEL systemic

[mg/kg bw/day]

Linear subgroup

26183-52-8

500-046-6

Decan-1-ol, ethoxylated

≥ 950

≥ 950

68439-50-9

500-213-3

Alcohols, C12-14, ethoxylated

≥ 1000

≥ 1000

9004-95-9

939-518-5

Hexadecan-1-ol, ethoxylated

≥ 1000

≥ 1000

68439-49-6

939-518-5

Alcohols, C16-18 (even numbered), ethoxylated, < 2.5 EO

≥ 1000

≥ 1000

9004-98-2

500-016-2

(Z)-9-Octadecen-1-ol ethoxylated

≥ 1000

≥ 1000

(local: 300)

Mixed branched & linear subgroup

160901-09-7

500-446-0

Alcohols, C9-11, branched and linear, ethoxylated

300

300

160901-19-9

500-457-0

Alcohols, C12-13, branched and linear, ethoxylated

≥ 1000

≥ 1000

106232-83-1

500-294-5

Alcohols, C12-15, branched and linear, ethoxylated

≥ 1000

≥ 1000

Evaluation of toxicity to reproduction as observed in available studies

The database for reproductive and developmental toxicity consists of the eight combined repeated dose toxicity studies with the reproduction / developmental toxicity screening test (OECD guideline 422), which are also discussed in the RDT section 7.5. In addition, four prenatal developmental toxicity studies (OECD guideline 414) in rats and two prenatal developmental toxicity studies in rabbits (two rat studies and one rabbit study in each of the ‘linear’ and ‘mixed branched & linear’ subgroups, respectively) are available. A third prenatal developmental toxicity study in rabbits is currently ongoing. It has been delayed due to the high workload of the test facility. As soon as reliable results are available, the hazard assessment with respect to developmental toxicity in rabbits will be updated.

Certain effects were noted in several of the studies, although the effects were not always considered to be adverse or toxicologically relevant (please refer to the endpoint summary 7.5 Repeated dose toxicity for more details). As can be expected for surfactants with known irritating properties, some effects caused by irritation at the site of contact (fore-stomach) were observed in the studies in the rat. Only parameters relevant for reproductive and developmental toxicity are summarised in this section. The full assessment of the repeated dose toxicity parameters investigated in the OECD 422 studies is provided in the endpoint summary for IUCLID section 7.5. The effects observed in the combined repeated dose toxicity study with the reproductive / developmental toxicity screening tests are summarised and discussed below.

Reproduction / developmental screening studies (OECD guideline 422)

The combined repeated dose toxicity study with the reproductive / developmental toxicity screening test was performed according to OECD guideline 422 under GLP conditions. Groups of 10 rats per sex received the test substance by daily oral gavage, 7 days a week for a minimum of 28 days. A similarly constituted control group was dosed with the vehicle (corn oil) only. The dose levels were set based on the guideline recommendation for substances not expected to exhibit strong systemic toxicity. Males were treated for 29 days whereas females that delivered were treated for 50-64 days (14 days prior to mating, the variable time to conception, the duration of pregnancy and at least 13 days after delivery). Females that failed to deliver or had a total litter loss were treated for 40-43 days. The following parameters and endpoints were evaluated: mortality/moribundity, clinical signs, functional observations, body weight and food consumption, clinical pathology, measurement of thyroid hormone T4 and TSH (F0 males and females), gross necropsy findings, organ weights and histopathologic examinations. In addition, a number of reproduction / developmental parameters were investigated in the F0 parental generation: estrous cycle, qualitative evaluation of spermatogenesis, premating time, number of corpora lutea, implantation sites and pre- and post-implantation loss, gestation duration, parturition and maternal care. In the F1 offspring litter size, viability, sex ratio and early postnatal pup development (mortality, clinical signs, body weights, sex, anogenital distance, areola/nipple retention and macroscopy, measurement of thyroid hormone T4 in PND 14-16 pups) was recorded. The mating and fertility indices, and gestation index were calculated.

Parental effects

The parental findings of the OECD 422 studies that were considered systemic and local effects have been discussed in detail in the endpoint summary for section 7.5, and only a brief summary of the systemic and local effects is included here.

Some effects or changes that appeared characteristic of the AE substances were observed: clinical signs like salivation, a flat and/or hunched posture, abnormal breathing sounds and piloerection were noted particularly at the high-dose level. The increased liver weight and changes in liver histopathology were noted in most of the studies, and were most likely adaptive changes as a reaction to an increased metabolic burden due to gavage administration of substantial amounts of test substance. A reduced body weight (gain) observed in most of the studies was considered a result of general discomfort in rats administered the test substance. The specific cause of the histological changes in the jejunum, which were considered non-adverse, could not be identified. The changes in the non-glandular stomach and glandular stomach were caused by the irritant effect of the AE substances at the site of contact, and therefore considered a local effect. For one substance, hexadecan-1-ol, ethoxylated, the effect was considered adverse, leading to a LOAEL at the highest dose level.

There was no clear difference in the occurrence of treatment-related effects between the substances in the linear subgroup and the mixed branched & linear subgroup. The severity and prevalence of clinical signs, however, varied between some of the substances in the linear and in the mixed branched & linear subgroup. In the studies with the substances alcohols, C9-11, branched and linear, ethoxylated and alcohols, C12-13, branched and linear, ethoxylated of the mixed branched & linear subgroup, the severity and/or prevalence of clinical signs led to the conclusion that this was toxicologically relevant at the highest dose level. For these two substances this lead to a LOAEL for systemic toxicity at the highest dose level.     

In the OECD 422 studies, no toxicologically significant changes were noted in the reproductive parameters pre-coital time, number of implantation sites, post-implantation survival, duration of gestation, litter size, viability at delivery and maternal care. No treatment-related effects on spermatogenesis or the reproductive organs were observed. In the study with alcohols, C9-11, branched and linear, ethoxylated a disturbed oestrus cycle was found in 5/10 females and judged to be adverse. However, this finding occurred in only one of the eight OECD 422 studies, was not observed in any of the subchronic repeated dose toxicity studies and had no impact on the fertility of the females in the study with alcohols, C9-11, branched and linear, ethoxylated. Therefore, it is considered an incidental effect of no toxicological relevance for this or any other AE category member substance.

The mating, fertility, gestation and live birth indices were similar between the control and treatment groups, in all the studies. The (lack of) treatment-related effects on fertility between the substances in the linear subgroup and the mixed branched & linear subgroup was consistent across the subgroups and the category.

Effects on offspring

Slightly lower offspring body weight (gain) on post-natal day 0, 7 and/or 13, compared with the control, was noted in two of five studies with substances in the linear subgroup. As the changes were minor, they were not considered to be toxicologically relevant. In the studies with the three ‘mixed branched & linear’ AE substances alcohols, C9-11, branched and linear, ethoxylated; alcohols, C12-13, branched and linear, ethoxylated; and alcohols, C12-15, branched and linear, ethoxylated; a lower body weight of the pups was noted for animals in the high-dose group (1000 mg/kg bw/day). Based on the magnitude of the changes observed, the finding was considered adverse in all three studies. For alcohols, C9-11, branched and linear, ethoxylated; and alcohols, C12-13, branched and linear, ethoxylated; clear maternal systemic toxicity was noted at the same dose level and the effect was considered secondary to the maternal adverse effects. For alcohols, C12-15, branched and linear, ethoxylated, no clear maternal systemic toxicity was observed. The occurrence of body weight change in offspring without maternal toxicity is considered specific to this substance, as this is the only case among the eight studies. This study is therefore only considered relevant to alcohols, C12-15, branched and linear, ethoxylated and the data will not be read-across to other substances in the AE category. For the other substances in the mixed branched & linear subgroup, OECD 422 studies are available.

The severity of the reduced body weight development was the only clear difference in the occurrence of treatment-related developmental effects between the substances in the linear subgroup and the mixed branched & linear subgroup.

Incidental findings in relation to developmental toxicity include a test substance-related increased concentration of serum T4 levels in the study with alcohols, C12-14, ethoxylated and a decrease in the mean (normalised) anogenital distance of female pups in the study with hexadecan-1-ol, ethoxylated. These findings were considered non-adverse as they were not associated with an adverse effect or values were within the range of historical control data.

No toxicologically relevant changes were noted in any of the other developmental parameters that were included in the studies (viability index, lactation index, sex ratio and early postnatal pup development consisting of mortality, clinical signs, areola/nipple retention, and macroscopic examination).

 

Conclusion on toxicity to reproduction (fertility)

The data on reproduction toxicity from the combined repeated dose toxicity studies with the reproduction / developmental toxicity screening test (OECD guideline 422) give a consistent picture of the effects across the category. Treatment with AE substances did not lead to adverse effects on parental reproductive parameters, incl. mating and fertility indices, precoital time, number of implantations, spermatogenic profiling, and histopathological examination of reproductive organs. No toxicologically relevant alterations in most developmental parameters were observed, including litter size, sex ratio, anogenital distance, placental weights of live foetuses and early postnatal offspring development consisting of mortality, clinical signs, areola/nipple retention, and macroscopic examination. In two studies, performed with substances in the mixed branched & linear subgroup, reduced offspring body weight was observed at a dose inducing significant maternal toxicity and this was considered a secondary effect of the maternal toxicity. In one study, performed with a substance in the mixed branched & linear subgroup (alcohols, C12-15, branched and linear, ethoxylated) reduced offspring body weight was observed at the highest dose level without clear maternal systemic toxicity. As this was the only study among the eight studies in which an effect was observed on the offspring generation only, this is considered specific to this substance and not relevant to the category as a whole. The NOAELs for toxicity to reproduction (fertility) are given in Table 1 above.

For octadecan-1-ol, ethoxylated (CAS No. 9005-00-9, EC No. 500-017-8) the following NOAELs are read across:

Oral (rat, m/f, OECD 422): NOAEL (reproduction) = 1000 mg/kg bw/day

Oral (rat, m/f, OECD 422): NOAEL (systemic toxicity) = 1000 mg/kg bw/day

Oral (rat, m/f, OECD 422): NOAEL (local toxicity) = 1000 mg/kg bw/day

For a detailed evaluation of the toxicity to reproduction potential of the substances in the AE category, please refer to the category justification attached to the category object.

Effects on developmental toxicity

Description of key information

Oral (rat, OECD 414): NOAEL (developmental toxicity) = 1000 mg/kg bw/day

Oral (rat, OECD 414): NOAEL (teratogenicity) = 1000 mg/kg bw/day

Read-across based on grouping of substances (category approach) considering all the available data on developmental toxicity in the AE category, in a Weight-of-Evidence approach.

Link to relevant study records
Reference
Endpoint:
developmental toxicity
Type of information:
read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Justification for type of information:
Please refer to the category justification provided in the category object.
Key result
Dose descriptor:
NOAEL
Effect level:
>= 1 000 mg/kg bw/day (nominal)
Based on:
test mat.
Basis for effect level:
other: no toxicologically relevant effects observed
Key result
Abnormalities:
no effects observed
Key result
Dose descriptor:
NOAEL
Effect level:
>= 1 000 mg/kg bw/day (actual dose received)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: no toxicologically relevant effects observed
Key result
Abnormalities:
no effects observed
Key result
Developmental effects observed:
no

For a detailed assessment of the developmental toxicity of the Alcohol Ethoxylates (AE) category, please refer to the category justification attached to the category object.

Conclusions:
Applying read-across based on grouping of substances (category approach), no toxicologically relevant effects in relation to developmental toxicity / teratogenicity and a NOAEL for developmental toxicity ≥ 1000 mg/kg bw/day are predicted for the registered substance.


are predicted for the registered substance.
Executive summary:

The available data on developmental toxicity in the 'linear' subgroup of the Alcohol Ethoxylates (AE) category indicates no toxicologically relevant effects for the registered substance. As explained in the category justification, the differences in molecular structure and composition between the registered substance and the members of the AE category are unlikely to lead to differences with respect to developmental toxicity.

Effect on developmental toxicity: via oral route
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEL
1 000 mg/kg bw/day
Study duration:
subacute
Species:
rat
Quality of whole database:
The available information comprises adequate and reliable (Klimisch score 1) studies from various source substances in the Alcohol Ethoxylates (AE) category with similar structures and intrinsic properties. Read-across is justified based on common toxicokinetic behaviour and consistent trends in environmental fate, ecotoxicological and toxicological properties of the category member substances. The data pool of the AE category is thus sufficient to fulfil the standard information requirements set out in Annexes VIII - X, Section 8.7, in accordance with Annex XI, Section 1.5, of the REACH Regulation (EC) No. 1907/2006.
Effect on developmental toxicity: via inhalation route
Endpoint conclusion:
no study available
Effect on developmental toxicity: via dermal route
Endpoint conclusion:
no study available
Additional information

No data on developmental toxicity are available for octadecan-1-ol, ethoxylated (CAS No. 9005-00-9, EC No. 500-017-8). In order to assess the potential for developmental toxicity, studies in the database of the Alcohol Ethoxylates (AE) category are considered in a read-across approach. Studies investigating developmental toxicity are available for the following AE substances (Table 1-3):

Table 1: Overview of OECD 422 studies, developmental toxicity

CAS No.

EC No.

Substance

Screening study (OECD 422)

 

NOAEL developmental (F1)

[mg/kg bw/day]

NOAEL systemic (F0)

[mg/kg bw/day]

Linear subgroup

26183-52-8

500-046-6

Decan-1-ol, ethoxylated

≥ 950

≥ 950

68439-50-9

500-213-3

Alcohols, C12-14, ethoxylated

≥ 1000

≥ 1000

9004-95-9

939-518-5

Hexadecan-1-ol, ethoxylated

≥ 1000

≥ 1000

(local: 300)

68439-49-6

939-518-5

Alcohols, C16-18 (even numbered), ethoxylated, < 2.5 EO

≥ 1000

≥ 1000

9004-98-2

500-016-2

(Z)-9-Octadecen-1-ol ethoxylated

≥ 1000

≥ 1000

Mixed branched & linear subgroup

160901-09-7

500-446-0

Alcohols, C9-11, branched and linear, ethoxylated

300

300

160901-19-9

500-457-0

Alcohols, C12-13, branched and linear, ethoxylated

300

≥ 1000

106232-83-1

500-294-5

Alcohols, C12-15, branched and linear, ethoxylated

300

≥ 1000

 

Table 2: Overview of OECD 414 studies in the rat

CAS No.

EC No.

Substance

Prenatal developmental toxicity study (OECD 414) in the rat

 

NOAEL [mg/kg bw/day]

 

Systemic (maternal)

Development

Teratogenicity

Linear

68439-50-9

500-213-3

Alcohols, C12-14, ethoxylated

300

300

≥ 1000

68920-66-1

500-236-9

Alcohols, C16-18 and C18-unsatd., ethoxylated

≥ 1000

≥ 1000

≥ 1000

Mixed linear & branched

160901-09-7

500-446-0

Alcohols, C9-11, branched and linear, ethoxylated

300

≥ 800

≥ 800

106232-83-1

500-294-5

Alcohols, C12-15, branched and linear, ethoxylated

≥ 1000

≥ 1000

≥ 1000

 

Table 3: Overview of OECD 414 studies in the rabbit

CAS No.

EC No.

Substance

Prenatal developmental toxicity study (OECD 414) in the rabbit

 

NOAEL [mg/kg bw/day]

 

Systemic (maternal)

Development

Teratogenicity

Linear

68439-50-9

500-213-3

Alcohols, C12-14, ethoxylated

30

200

200

68920-66-1

500-236-9

Alcohols, C16-18 and C18-unsatd., ethoxylated

(study ongoing)

-

-

Mixed linear & branched

106232-83-1

500-294-5

Alcohols, C12-15, branched and linear, ethoxylated

100

 400

400

 

Evaluation of developmental toxicity as observed in available studies

The database for reproductive and developmental toxicity consists of the eight combined repeated dose toxicity studies with the reproduction / developmental toxicity screening test (OECD guideline 422), which are discussed under “Effects on fertility” in section 7.8 and in the repeated dose toxicity section 7.5. In addition, four prenatal developmental toxicity studies (OECD guideline 414) in rats and two prenatal developmental toxicity studies in rabbits (two rat studies and one rabbit study in each of the ‘linear’ and ‘mixed branched & linear’ subgroups, respectively) are available. A third prenatal developmental toxicity study in rabbits is currently ongoing. It has been delayed due to the high workload of the test facility. As soon as reliable results are available, the hazard assessment with respect to developmental toxicity in rabbits will be updated.

Certain effects were noted in several of the studies, although the effects were not always considered to be adverse or toxicologically relevant (please refer to the endpoint summary 7.5 Repeated dose toxicity for more details). As can be expected for surfactants with known irritating properties, some effects caused by irritation at the site of contact (fore-stomach) were observed in the studies in the rat. The effects observed in the prenatal developmental toxicity studies are summarised and discussed below.

 

Prenatal developmental toxicity studies in rats

The prenatal developmental toxicity studies were performed according to OECD guideline 414. Groups of 22 dams were administered the test substance by oral gavage, 7 days a week on gestation day 6 – 20. The dose levels applied were either the guideline-recommended top dose of 1000 mg/kg bw/day or were established in appropriate dose range-finding pre-studies that identified top doses inducing significant toxicity without imposing unnecessary suffering on the laboratory animals. The control group was treated according to the same protocol and received the vehicle (corn oil) only. All the females were time-mated and the day of mating was gestation day 0 (Day 0 post-coitum). The dams were sacrificed on gestation day 21.The following parameters were recorded in the dams: mortality/moribundity, clinical signs, body weight and food consumption, water consumption (monitored by visual inspection), thyroid hormone levels (T3, T4 and TSH), macroscopic examination, microscopic examination of the thyroid gland, gravid uterus weight, number of corpora lutea, number of implantations, number of early and late resorptions, and number of live and dead fetuses. The following parameters were recorded in the foetuses: body weight, sex, anogenital distance, external examination, soft tissue examination and skeletal examination for malformations and variations.

In the study with alcohols, C12-14, ethoxylated it was suspected that subgroups 1 and 2 may have been switched after mating. This would indicate that animals of subgroup 1 were dosed on gestation day 5 - 19 and sacrificed on gestation day 20, and animals of subgroup 2 were dosed on gestation day 7 - 21 and sacrificed on gestation day 22. Subgroups 3 and 4 were dosed according to schedule. A full evaluation of the data was still possible, as subgroups 3 and 4 were dosed according to schedule and sufficient data was available, all dose groups were evenly divided over the different subgroups, data of applicable parameters were evaluated separately for the different subgroups, if deemed necessary, and possible test item-related trends were consistent between the different subgroups. Furthermore, for the majority of animals, the critical period of organogenesis was completely included in the dosing period the suspected slight shift in dosing period for subgroups 1 and 2 (i.e., one day earlier and one day later, respectively) had no impact on the overall conclusion. It was therefore concluded that the overall integrity of the study and the interpretation of the study results and conclusions was not compromised.

 

Maternal effects

Maternal effects observed in the studies were mostly related to clinical signs and body weight development. Clinical signs included salivation, piloerection, hunched posture and abnormal breathing sounds and were considered a physiological response to treatment rather than signs of systemic toxicity. Terminal body weights and body weight gain were lower in high-dose females than in the control in all four OECD 414 studies in the rat. In the study with alcohols, C12-14, ethoxylated this resulted in terminal body weights of 7 - 11% lower than controls. The mean overall food intake was reduced by 11 - 24% compared with controls. While effects on body weight development were considered adverse for alcohols, C12-14, ethoxylated, they were not considered adverse for the other three OECD 414 studies in rats due to the limited difference between the treated and control animals. The body weight gain corrected for gravid uterus was slightly reduced compared with control in all four studies, but not considered a toxicologically relevant effect as the difference was limited and not significant.

A reduction in serum levels of total T3 and T4 was noted in the study with alcohols, C16-18 and C18-unsatd., ethoxylated, but the mean value of both parameters remained within the historical control data. Reduced levels of T3 and increased levels of TSH were also noted in the studies with alcohols, C12-14, ethoxylated and alcohols, C12-15, branched and linear, ethoxylated. As there were no correlated histopathological changes and the values remained within the range of the historical control data, the changes in thyroid hormones were not considered to be toxicologically relevant.

In the study with alcohols, C9-11, branched and linear, ethoxylated, a single (non-pregnant) female of the high-dose group (800 mg/kg bw/day) was sacrificed in extremis on gestation day 12, as it was in poor health with laboured breathing, lateral recumbent position, a weak appearance and decreased activity, cold to the touch and slight salivation. The days before its death, slight body weight loss was noted for gestation day 6 - 9, with no recovery thereafter. In addition, the food consumption was lower during gestation day 6 - 12. Although no definite cause of the poor health could be determined at necropsy (i.e. no macroscopic abnormalities), a possible relation to treatment with the test substance could not be excluded. In the study with alcohols, C9-11, branched and linear, ethoxylated the macroscopic evaluation showed an irregular surface in the forestomach of 1/22 females in the mid-dose group and 5/22 females of the high-dose group, respectively. No microscopic evaluation was performed. However, this finding is in agreement with the observations in the subacute and subchronic repeated dose toxicity studies with the substance, and it is classified for its eye irritation potential. It is likely that the effects is caused by a local irritant effect.

No treatment-related and/or toxicologically relevant changes were noted for any of the other maternal systemic and reproductive parameters recorded in the studies (thyroid gland weights, microscopic evaluation of the thyroid gland, uterine contents, corpora lutea, pre- and post-implantation sites, and pre- and post-implantation loss).

 

Effects on offspring

The mean fetal body weights (male, female and combined) were reduced, compared with control, in the studies with alcohols, C12-14, ethoxylated and alcohols, C16-18 and C18-unsatd., ethoxylated. For alcohols, C12-14, ethoxylated the effect was considered adverse as the mean values were below or at the lower end of the historical control range, while for alcohols, C16-18 and C18-unsatd., ethoxylated the effect was not considered to be adverse as the difference in mean body weight was around 3% for all treatment groups.

In the study with alcohols, C12-14, ethoxylated effects relating to offspring development were found. These effects, noted in the high-dose group (1000 mg/kg bw/day), were all skeletal variations: signs of delays of ossification (unossified metacarpals, sternebrae and hyoid body, incompletely ossified sternebrae, skull bones (e.g., supraoccipital, parietal and frontal), vertebra (cervical and sacral) and pelvic girdles (ischium)). Incompletely ossified skull bones also occurred across the control and low-dose group (100 mg/kg bw/day). None of the findings was considered adverse as the effects are defined as a variation. The degree of ossification was correlated with the body weight of the respective foetuses and the body weights varied by subgroup, due to the inadvertent switch of two subgroups. A few cases of external, visceral and skeletal malformations and -variations were recorded in the remaining three studies in the rat, included cleft palate, a small upper jaw, exencephaly, dilated brain ventricles and bent humeri. These cases were all considered to be incidental due to the low number or were observed in all groups including control in similar numbers.

No toxicologically relevant changes were observed in any of the remaining developmental parameters investigated in the studies (litter size, sex ratio, anogenital distance and placental weights of live foetuses).

 

 

Prenatal developmental toxicity studies in rabbits

The prenatal developmental toxicity studies were performed according to OECD guideline 414. Groups of 22 dams were administered the test substance by oral gavage, 7 days a week on gestation day 7 – 28. The dose levels applied were established in appropriate dose range-finding pre-studies that identified top doses inducing significant toxicity without imposing unnecessary suffering on the laboratory animals. The control group was treated according to the same protocol and received the vehicle (propylene glycol) only. All the females were time-mated and the day of mating was gestation day 0 (Day 0 post-coitum). The dams were sacrificed on gestation day 29.The following parameters were recorded in the dams: mortality/moribundity, clinical signs, body weight and food consumption, water consumption (monitored by visual inspection), macroscopic examination, gravid uterus weight, number of corpora lutea, number of implantations, number of early and late resorptions, and number of live and dead fetuses. The following parameters were recorded in the foetuses: body weight, sex, external examination, soft tissue examination and skeletal examination for malformations and variations.

 

Behavioural episodes observed in dams

In both of the available prenatal developmental toxicity studies in rabbits incidences during which individual dams showed severe clinical signs were noted. In the study with alcohols, C12-14, ethoxylated, the episodes occurred on several (consecutive) days of treatment from gestation day 15 onwards in 5/22 animals of the high-dose group (200 mg/kg bw/day). The episodes consisted of the following clinical signs: increased respiratory rate, shallow breathing, uncoordinated movements, lying on one side, head tilt, prostrate position, decreased activity and/or extensor rigidity of both hind limbs, prior to and/or during the first post-dose observation. In addition, uncoordinated movement and/or lying on the side was noted in 18/22 and 16/22 animals, respectively, in the high-dose group. The episodes were not observed in the low- (30 mg/kg bw/day) and mid-dose group (80 mg/kg bw/day).

In the high-dose group (400 mg/kg bw/day) of the study with alcohols, C12-15, branched and linear, ethoxylated, 2/19 females similar incidences were noted on gestation day 20 and 22, 2-4 h post-dose. A combination of the following clinical signs was observed: uncoordinated movements with extensor rigidity of both hind limbs, rolling and/or shallow breathing, decreased activity, limited use of both hind limbs, lameness of both hind limbs, abnormal gait, lying on the side, difficulty rising and/or abnormal respiratory rate. Extensor rigidity of both hind limbs, lying on the side, prostrate position, erected fur and/or hunched posture was also noted in these two females as well as in three additional females of this dose group on individual days between gestation day 23 and 28. Moreover, one female in the mid-dose group (250 mg/kg bw/day) showed extensor rigidity of both hind limbs, lying on the side, prostrate position, erected fur and/or hunched posture on individual days between gestation day 23 and 28, mostly 2-4 h post-dose.

The behavioural episodes or individual clinical signs associated with them, e.g. uncoordinated movement and extensor rigidity of both hind limbs, started around gestation day 15, about 7-10 days after the treatment with the test substances started. Only a minority of the females were subject to the episodes. Clinical signs observed in other females included decreased activity, hunched posture, erected fur and prostrate position. These clinical signs are probably a consequence of a disturbed well-being of the pregnant rabbits as a result the treatment. They do not appear to be associated with the episodes.

The cause of the episodes is unknown. It is notable that they started around 7-10 days after initiation of the dosing and that only a fraction of the test animals - even in the high-dose groups - was subject to all the clinical signs associated with the ‘episodes’. Certain clinical signs characteristic for the episodes were also observed in other females. It is well-known that rabbits - and especially pregnant rabbits - are more sensitive than other laboratory animals in general and may consequently show more (severe) adverse effects of treatment with a xenobiotic test material. However, no comparable observations were found in the toxicological literature and none of the toxicological and veterinary experts involved in (evaluation of) the studies was aware of similar effects in rabbits during studies. There were no indications of similar or comparable effects found in the prenatal developmental toxicity studies in rats.

One possible explanation of the episodes that was considered is that they indicate a rabbit-specific metabolisation of AE substances leading to metabolites responsible for the strong effects observed in rabbits but not in rats and other species. Since the ‘episodes’ were reported to occur approx. 1 to 4 h after dosing, it is possible that metabolisation of the substances’ constituents is needed, i.e. that certain metabolites are responsible for the severe clinical signs. In order to evaluate this assumption, the results of the comparative in vitro metabolisation investigation reported in section 7.3 were evaluated in the context of the observed clinical signs. The study did not reveal substantial species differences with respect to the metabolisation of AE substances. Different metabolisation rates and half-lives were observed as can be expected for different species. However, the metabolites identified after incubation with human, rat and hamster liver S9 fractions and hepatocytes did not differ qualitatively. Although the amount of certain metabolites varied between the species, no differences in metabolic pathways were identified. All three investigated species (human, rat and hamster) produced the same metabolite spectrum. For a detailed discussion of the comparative in vitro metabolism investigation performed with selected AE test substances and of the ‘common underlying mechanism’, please refer to section 7. The findings of the in vitro metabolism investigation are a clear indication that there are no species differences in relation to the metabolism of AE substances. This result is also supported by studies reviewed in the HERA report (refer to section 7.1). There are no indications that AE substances are metabolised in a different way in rabbits when compared to humans, rats and hamsters. Based on all available information, it is reasonable to assume that the episodes observed in the rabbit studies - but not in any of the available studies in rats - are a consequence of the generally higher sensitivity of pregnant rabbits to treatment under similar conditions. In addition to the generally higher sensitivity of rabbits under similar conditions, it should be noted that the studies in rats were all performed using corn oil as vehicle whereas propylene glycol had to be used in the rabbit studies. While corn oil is known to mitigate effects of local irritation, propylene glycol cannot reduce local irritation effects. The treated rabbits may consequently be more affected by the gavage exposure to an irritant substance. The difference between using corn oil and propylene glycol as the vehicle in combination with the generally higher susceptibility of pregnant rabbits, compared with rats, to treatment under similar conditions may contribute to the ‘episodes’. Therefore, the behavioural episodes are not considered to be an indication of a rabbit-specific systemic toxicity. Since an additional prenatal developmental toxicity study in rabbits is currently ongoing with alcohols, C16-18 and C18-unsatd., ethoxylated, a final evaluation of the effects observed in pregnant rabbits can only be made when the results of this study will be available.

 

Other maternal effects

Up to 3 females died or were sacrificed in extremis prior to scheduled sacrifice in all the control and treatment groups, in both studies. This was partly due to the behavioural episodes described above, partly due to animals that were in poor health as they were not eating enough, partly caused by gavage error, and partly due to early delivery. In the study with alcohols, C12-14, ethoxylated, one case in the high-dose group was considered adverse as this animals had severe behavioural episodes. In the study with alcohols, C12-15, branched and linear, ethoxylated, one case in the mid-dose group and three in the high-dose group were considered adverse due to body weight loss and clinical signs. The mean overall body weight gain was reduced by 7-11% in all treatment groups in the study with alcohols, C12-14, ethoxylated. The changes were limited and not statistically significant, and therefore not considered to be toxicologically relevant. In the study with alcohols, C12-15, branched and linear, ethoxylated the overall body weight gain was reduced by 35%, compared with control (not statistically significant). This was a toxicologically relevant effect due to the large change. The reduction in food consumption was considered toxicologically relevant only in the high-dose group of the study with alcohols, C12-15, branched and linear, ethoxylated as it was 18% lower than for control. 

Terminal body weights and body weight gain were lower in high-dose females than in the control in all four OECD 414 studies in the rat. In the study with alcohols, C12-14, ethoxylated this resulted in terminal body weights of 7 - 11% lower than controls. The mean overall food intake was reduced by 11 - 24% compared with controls. While effects on body weight development were considered adverse for alcohols, C12-14, ethoxylated, they were not considered adverse for the other three OECD 414 studies in rats due to the limited difference between the treated and control animals. The body weight gain corrected for gravid uterus was slightly reduced compared with control in all four studies, but not considered a toxicologically relevant effect as the difference was limited and not significant.

In the females sacrificed according to the protocol on gestation day 29, prominent lobular architecture of the liver was noted in 1/21, 2/20, 3/21 and 3/21 females in the control, low- mid- and high-dose group, respectively. In addition, 1/21 mid-dose females showed an abnormal appearance of the medial hepatic lobe and 2/21 high-dose females pale discoloration in the liver. The liver changes were considered treatment-related and a result of the metabolic load of the treatment, but not toxicologically relevant.

No treatment-related effects were noted on litter loss, number of corpora lutea, number of pre- and post-implantations, number of early and late resorptions, and number of live and dead fetuses.

 

Effects on offspring

In the study with alcohols, C12-14, ethoxylated, the mean body weight for male and female fetuses combined was 5, 6 and 8% lower in the low- mid- and high-dose group, respectively, compared with the control. This was considered a treatment-related, but minor, effect and secondary to the systemic maternal toxicity. The changes were therefore not considered adverse. No effects on body weight (gain) were noted in the other study in the rabbit.

A few cases of external malformations were recorded in the two studies in the rabbit, including malrotated hind limbs, cleft palate, hyper-flexed forepaws and malrotated hind paws. Several visceral malformations affecting the subclavian artery, kidneys, heart and major blood vessels, lung, diaphragm, brain and eye as well as skeletal malformations concerning thoracic, lumbar or caudal vertebrae, sternebrae or nasal bones were found. These cases were all considered to be incidental due to the low number or were observed in all groups including control in similar numbers. No treatment-related effects were noted on litter loss, number of corpora lutea, number of pre- and post-implantations, and number of early and late resorptions.

In conclusion, despite the occurrence of ‘episodes’ in the dams, no toxicologically relevant changes were noted in the offspring for any developmental parameters and there was no teratogenicity in the prenatal developmental studies in rabbits.

 

Conclusion on developmental toxicity and teratogenicity in the rat and the rabbit

The data on developmental toxicity from the combined repeated dose toxicity study with the reproduction / developmental toxicity screening tests (OECD 422) and the prenatal developmental toxicity studies (OECD 414) in a rodent (rat) and a non-rodent species (rabbit) give mainly a consistent picture of the effects across the category and species.

Treatment with AE substances according to OECD guideline 422 did not lead to adverse effects on most developmental parameters, including litter size, sex ratio, anogenital distance, placental weights of live foetuses and early postnatal offspring development consisting of mortality, clinical signs, areola/nipple retention, and macroscopic examination. In two studies, performed with substances in the mixed branched & linear subgroup, reduced offspring body weight was observed at a dose inducing significant maternal toxicity and this was considered a secondary effect of the maternal toxicity. In the OECD 422 study with alcohols, C12-15, branched and linear, ethoxylated, the mean body weight of male pups were statistically significantly decreased at PND 7 and 13 in the high-dose group (1000 mg/kg bw/day). In addition, mean body weights of female pups in the high-dose group were decreased at PND 13, though not reaching statistical significance. These findings were considered adverse. However, a significant result was only observed in males at PND 7 and 13 and not in the combined mean body weight for males and females, or for females individually. The reduced weight of male pups is therefore more likely an incidental effect as it is unlikely males put on less weight than females under the same treatment circumstances. No effects on body weight were recorded in the prenatal developmental toxicity study performed with alcohols, C12-15, branched and linear, ethoxylated. As this was the only study among the eight OECD 422 studies in which an effect was observed on the offspring generation only, this is considered specific to this substance and not relevant to the category as a whole.

In prenatal developmental toxicity studies performed in rats and rabbits, the maternal effects observed in pregnant rats and rabbits were primarily clinical signs, and reduced body weight development and food consumption, compared with the control. An increased occurrence of ‘episodes’ was recorded in maternal rabbits only, during which the animals showed severe clinical signs that in some cases led to unscheduled sacrifice. No treatment-related and/or toxicologically relevant changes were noted for any other maternal systemic and reproductive parameters recorded in the studies, including: thyroid gland weights (in the rat), thyroid hormone levels (in the rat), microscopic evaluation of the thyroid gland, uterine contents, corpora lutea, pre- and post-implantation sites, pre- and post-implantation loss, viability and litter loss.

In the fetuses, reduced fetal body weight was considered toxicologically relevant in the study with alcohols, C12-14, ethoxylated, however, this was a secondary effect of maternal systemic toxicity. No toxicologically relevant changes were observed in the offspring in any of the remaining developmental parameters, including: litter size, sex ratio, anogenital distance (in the rat) and placental weights of live fetuses. No teratogenic effects were observed in the prenatal developmental studies performed in rats and rabbits.

There was no clear difference in (lack of) reproductive and developmental and effects between the linear subgroup and the mixed branched & linear subgroup, indicating consistency across the category. 

The NOAELs for developmental toxicity and teratogenicity are given in Table 2 and 3 above.

For octadecan-1-ol, ethoxylated (CAS No. 9005-00-9, EC No. 500-017-8) the following NOAELs are read across:

Oral (rat, OECD 414): NOAEL (developmental toxicity) = 1000 mg/kg bw/day

Oral (rat, OECD 414): NOAEL (teratogenicity) = 1000 mg/kg bw/day

For a detailed evaluation of the toxicity to reproduction potential of the substances in the AE category, please refer to the category justification attached to the category object.

 

Justification for classification or non-classification

The available data on toxicity to reproduction obtained with octadecan-1-ol, ethoxylated (CAS No. 9005-00-9, EC No. 500-017-8) and with other members of the Alcohol Ethoxylates (AE) category do not meet the criteria for classification according to the CLP Regulation (EC) No. 1272/2008 and are therefore conclusive but not sufficient for classification.

Additional information