Isotridecanol, ethoxylated

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

Reproductive / developmental screening test (oral, rat, OECD 421): NOAEL (systemic toxicity) = 500 mg/kg bw/day, NOAEL (reproductive toxicity) = 500 mg/kg bw/day

Conclusion based on data obtained with isotridecanol, ethoxylated, < 2.5 EO (CAS No. 69011-36-5, EC No. 500-241-6).

Link to relevant study records

Reference

Endpoint:

screening for reproductive / developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

3 Mar - 14 Aug 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 421 (Reproduction / Developmental Toxicity Screening Test)

Version / remarks:

adopted in 2016

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Details on species / strain selection:

The Sprague Dawley rat is the species and strain of choice because it is accepted by many
regulatory authorities and there are ample experience and background data on this species
and strain.

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Envigo RMS srl, San Pietro al Natisone, Italy
- Females: nulliparous and non-pregnant
- Age at study initiation: 7 - 8 weeks (at arrival) + 25 days (acclimatisation)
- Weight at study initiation: (P) Males 208 - 218 g, females 182 - 194 g
- Housing: From arrival to pairing, up to 5 of one sex to a cage; during mating, one male to one female in a cage. After mating, males were re-caged as they were before mating. The females were transferred to individual solid bottomed cages for the gestation period, birth and lactation.
- Diet: Rodent diet 4 RF 21 (Mucedola srl, SettimoMilanese, Italy), ad libitum
- Water: Via water bottles, ad libitum
- Acclimatisation period: 25 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 24
- Humidity (%): 40 - 70
- Air changes (per hr): 15 - 20
- Photoperiod (hrs dark / hrs light): 12 / 12

IN-LIFE DATES: From: 3 Mar 2020 To: 8 May 2020

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
The required amount of test item was dissolved in the vehicle. The preparations were made weekly (concentrations of 12.5, 37.5 and 125 mg/mL). Concentrations were calculated and expressed in terms of test item as supplied.

VEHICLE
- Justification for use and choice of vehicle: Corn oil had been determined previously as a suitable vehicle for the test item.
- Amount of vehicle (if gavage): 4 mL/kg bw

Details on mating procedure:

- M/F ratio per cage: 1/1
- Length of cohabitation: Until copulation occured or 14 days as the maximum period.
- Proof of pregnancy: Sperm in vaginal smear, vaginal plug in situ or copulation plugs found in the cage tray.
- After successful mating each pregnant female was caged: individually

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Analysis was performed in a separate study in order to validate both the analytical method and the preparation procedure and to verify the stability of the preparations. The analytical method was validated in the range from 10 to 200 mg/mL. Linearity, accuracy and precision were within the limits stated in validation protocol (r > 0.98; accuracy 85 - 115%; precision CV < 5%). In the same study, 28 h stability at room temperature and 8 day stability at 2 - 8 °C were verified in the range from 10 to 200 mg/mL. The proposed preparation procedure for the test item was checked in the same by chemical analysis (concentration) to confirm that the method was suitable.

Duration of treatment / exposure:

Males
Animals were dosed once a day, 7 days a week, for 2 consecutive weeks prior to pairing, through the pairing period and thereafter until the day before necropsy (Day 32). Males were treated for a total of 31 days. Dose volumes were adjusted once per week for each animal according to the last recorded body weight.

Females
Animals were dosed once a day, 7 days a week, for 2 consecutive weeks prior to pairing and thereafter during pairing, gestation and post partum periods until Day 13 post partum (for at least 51 days). One non pregnant female, females with total litter loss and those that did not mate were dosed up to the day before necropsy. Dose volumes were adjusted once per week for each animal according to the last recorded body weight up to mating. During the gestation period, dose volumes were calculated according to individual body weight on Days 0, 7, 14 and 20 of gestation and on Days 1, 4, 7 and 13 post partum.

Frequency of treatment:

Daily, 7 days per week

Dose / conc.:

50 mg/kg bw/day (nominal)

Dose / conc.:

150 mg/kg bw/day (nominal)

Dose / conc.:

500 mg/kg bw/day (nominal)

No. of animals per sex per dose:

20

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: The dose levels were selected based on the results of a Dose Range Finding Study (ERBC Study No. E0407) and from a 13-week oral toxicity study (GLP compliant study, ERBC Study No. A3596). and with the aim to produce graded responses to the test item.

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS AND MORTALITY: Yes
- Time schedule: Mortality was checked at least twice daily, clinical signs were checked at least once daily.

DETAILED CLINICAL OBSERVATIONS: No

BODY WEIGHT: Yes
- Time schedule for examinations: Males were weighed weekly from allocation to termination, females were weighed weekly from allocation to positive identification of mating and on
Days 0, 7, 14 and 20 of gestation. Dams were also weighed on Days 1, 4, 7, 13 post partum and just before necropsy.

FOOD CONSUMPTION:
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: No
- Details: The weight of food consumed by each cage of males and females was recorded weekly during the pre-mating period starting from Day 1 of dosing. Individual food consumption for the females was also measured on Days 7, 14 and 20 of gestation starting from Day 0 post coitum and on Days 7 and 13 post partum starting from Day 1 post partum.

WATER CONSUMPTION: No

SERUM HORMONES: Measurement of total triiodothyronine (total T3), total thyroxine (total T4) and thyroid stimulating hormone (TSH) was conducted for all F0-males.

Oestrous cyclicity (parental animals):

Vaginal smears were taken in the morning from Day 1 of treatment, up to and including positive identification of mating (not less than 2 weeks before the pairing).
The vaginal smear data were examined to determine the following:
– anomalies of the oestrous cycle,
– pre-coital interval (i.e., the number of nights paired prior to the detection of mating).
Vaginal smears were also taken from all females, before despatch to necropsy.

Sperm parameters (parental animals):

Parameters examined in F0-males: Testis weight and epididymis weight.
- Additional examination: A morphological evaluation of the seminiferous epithelium (staging of spermatogenic cycle) was performed. The evaluation took into account the tubular stages of the spermatogenic cycle, in order to identify treatment-related effects, such as: missing germcell layers or types, retained spermatids, multinucleated or apoptotic germcells and sloughing of spermatogenic cells into the lumen.

Litter observations:

STANDARDISATION OF LITTERS
On Day 4 post partum, all pups were weighed and litters in excess of 8 offspring were culled to 8 (4 males and 4 females, where possible) by a random selection.

PARAMETERS EXAMINED
The following parameters were examined in F1 offspring: Number and sex of pups, stillbirths, live births, postnatal mortality, presence of gross anomalies, weight gain, physical or behavioural abnormalities, anogenital distance (AGD), pup weight on the day of AGD, presence of nipples/areolae in male pups. Particular attention was paid to the external reproductive genitals which were examined for signs of altered development.

GROSS EXAMINATION OF DEAD PUPS
Pups found dead were examined for external and internal abnormalities; possible cause of death was/was not determined for pups born or found dead.

SERUM HORMONES
Blood samples were taken and measurement of total triiodothyronine (total T3), total thyroxine (total T4) and thyroid stimulating hormone (TSH) was conducted for all pups on Day 14 post partum.

Postmortem examinations (parental animals):

SACRIFICE
Parental animals that had completed the scheduled test period, were killed by exsanguination under isoflurane anaesthesia. A detailed post mortem examination was conducted (including examination of the external surface and orifices).

-Males: surviving males were killed after the end of mating period on Day 32 of the study. Males were treated for a total of 31 days.

-Females: females with live pups were killed on Day 14 post partum. Females were dosed for a
minimum of 51 consecutive days. The females showing no evidence of copulation were killed 27 days after the last day of the mating session.

GROSS NECROPSY
- Gross necropsy consisted of external and internal examinations including the cervical, thoracic, and abdominal viscera. Parental females were examined also for the number of visible implantation sites and the number of corpora lutea.

HISTOPATHOLOGY / ORGAN WEIGHTS
Histopathology/organ weights was conducted for the following tissues: Adrenal glands, Brain (cerebrum, cerebellum, medulla/pons), Clitoral gland, Epididymides, Kidneys, Liver, Mammary gland - Females, Mammary gland - Males, Ovaries with oviducts, Parathyroid glands, Pituitary gland, Penis, Prostate gland (dorsolateral and ventral), Sciatic nerve, Seminal vesicles with coagulating glands, Spleen, Stomach, Testes, Thymus (where present), Thyroid, Uterus – cervix, Vagina.

Postmortem examinations (offspring):

SACRIFICE
All pups found dead in the cage were examined for external and internal abnormalities. All culled pups sacrificed on Day 4 post partum were subjected to an external examination. Sex was determined by internal gonads inspection. All live pups sacrificed on Day 14 post partum were killed and examined for external abnormalities and sex confirmation by gonadal inspection. Thyroid was weighed from one male and female from each litter (if possible the same pup selected for serum hormone determination) and preserved in 10% neutral buffered formalin. The thyroid weight was determined after fixation. Pups with abnormalities were retained in 10% neutral buffered formalin.

Statistics:

Standard deviations were calculated as appropriate. For variables, e.g. body weight, food consumption, clinical pathology parameters and organ weights, the significance of the differences amongst group means was assessed by Dunnett’s test or a modified t test, depending on the homogeneity of data. Statistical analysis of histopathological findings was carried out by means of the nonparametric Kolmogorov-Smirnov test. The non-parametric Kruskal-Wallis analysis of variance was used for the other parameters. Intergroup differences between the control and treated groups were assessed by the nonparametric version of the Williams test. The criterion for statistical significance was p < 0.05. The mean values, standard deviations and statistical analysis were calculated from actual values in the computer without rounding off.

Reproductive indices:

Males:
Copulation Index (%) = no. of males with confirmed mating/no. of males cohabitated × 100
Fertility Index (%) = no. of males which induced pregnancy/no. of males cohabitated × 100

Females
Copulatory Index (%) = no. of females with confirmed mating/no. of females cohabitated × 100
Fertility Index (%) = no. of pregnant females/no. of females cohabitated × 100
Pre-implantation loss was calculated as a percentage from the formula: no. of corpora lutea − no. of implantations/no. of corpora lutea × 100

Males and females
Pre coital Interval = The numbers of nights paired prior to the detection of mating

Offspring viability indices:

Pre-natal loss on Day 0 post partum, before culling, was calculated as a percentage from the formula:
no. of visible implantations − live litter size at birth/no. of visible implantations × 100

Pup loss at Day 0 post partum was calculated as a percentage from the formula:
Total litter size − live litter size/Total litter size × 100

Post-natal loss on Day 4 post partum (before culling) was calculated as a percentage from the formula:
Live litter size at birth − live litter size at Day 4(before culling)/Live litter sizeat birth × 100

Post-natal loss on Day 13 post partum (after culling) was calculated as a percentage from the formula:
Live litter size on Day 4(after culling) − live litter size on Day 13/Live litter size on Day 4 (after culling) × 100

Sex ratios were calculated at birth, on Days 4 and 14 post partum and were presented as the percentage of males per litter.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

In all males receiving 500 mg/kg bw/day and in 9/10 males receiving 150 mg/kg bw/day, salivation was sporadically observed during the treatment period. Also 3/10 males receiving 50 mg/kg bw/day showed salivation on three occasions. Salivation was observed sporadically during the treatment period in all females receiving 500 mg/kg bw/day and 150 mg/kg bw/day. No clinical signs were observed during the study in females receiving 50 mg/kg/day. Salivation was considered treatment-related but not adverse.

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

In males body weight and body weight gain recorded during the study were comparable to the control group males. In female animals, on Days 4 and 13 of the post partum period and limited to the high dose group, statistically significant slight decrease in body weight gain (-6%) was noted, when compared to the control group. Body weight gain in high dose females, increased during the first week of treatment (Day 8 of the premating phase).

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Food consumption recorded in male animals during the premating period was unaffected by treatment. A statistically significant decrease (ranging from -12% to -22%) in food consumption was evident in all treated groups of female animals at the end of the post partum period only.

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Endocrine findings:

no effects observed

Description (incidence and severity):

No differences between control and parental treated males were recorded in thyroid hormones (T3, T4 and TSH) determination performed at the end of the study.

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Treatment-related changes were present in the stomach (non-glandular region) of mid-dose and high-dose animals of both sexes. Epithelial hyperplasia was seen in the non-glandular region of the stomach (forestomach) in 9/10 males and 9/10 females of the high dose group, with minimal to moderate degree for males and minimal to mild degree for females, whereas the same lesion, of minimal degree, was noted in 1/10 males and 2/10 females of the mid-dose group. The gastric lesion was characterised by convolutions of the epithelium with downward projections of rete peg-like structures and sometimes associated with the presence of hyperkeratosis with chronic inflammation and/or oedema in the submucosa, and in one instance with mucosal erosion of non-glandular region of the stomach. Epithelial hyperplasia of the non-glandular region of the stomach (forestomach) was evaluated to be a local irritant effect relevant to the rat. Since humans do not have a forestomach, the changes are considered not relevant to human.
In one male of the high-dose group, hepatocytic necrosis of the liver associated with cortical hypertrophy of the adrenals (monolateral) was noted. As the liver change was seen only once in the high-dose group and such a change is known to occur sporadically in untreated animals, the present case was considered an incidental finding, whereas the cortical hypertrophy of the adrenals was considered secondary to the stress induced by the liver and gastric (epithelial hyperplasia) lesions and therefore not related to treatment.

Histopathological findings: neoplastic:

not examined

Other effects:

not examined

Reproductive function: oestrous cycle:

no effects observed

Description (incidence and severity):

The total number of oestrous cycles observed in all females before pairing (number of non-sequential days in which the females were in oestrous) were similar between control and treated groups and was of 2-3 cycles. Vaginal smears examined on the day of necropsy showed the phase of diestrous for the majority of females sacrificed on Day 14 post partum. The non-pregnant females and those not mated, showed phase of the dioestrus on the day of necropsy but the oestrous cycle during the study was regular.

Reproductive function: sperm measures:

no effects observed

Description (incidence and severity):

Seminiferous tubules were evaluated with respect to their stage in the spermatogenic cycle and to the integrity of the various cell types within the different stages; regular layering in the germinal epithelium was noted in all control and high-dose males.

Reproductive performance:

no effects observed

Description (incidence and severity):

Copulatory index was 100% for both males and females of control and low dose groups and 90% for for mid- and high-dose groups. Fertility index both for males and females was 100% each for control and low dose groups, 90% for mid-dose group and 80% for high dose group. One mid-dose female and one high dose female did not mate. These cases were considered incidental. The number of copulatory plugs were similar between groups.
Gestation length was similar between treated and control groups and no signs of dystocia were observed. Corpora lutea, implantations and pre-implantation loss, live litter size and pre-natal loss (percentage) did not show dose-related or treatment-related differences.

Key result

Dose descriptor:

NOAEL

Remarks:

reproduction

Effect level:

500 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: No toxicologically relevant effects observed

Dose descriptor:

NOAEL

Remarks:

systemic

Effect level:

500 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

Clinical signs:

effects observed, non-treatment-related

Description (incidence and severity):

No food intake (milk), small appearance, pallor and cold to touch were the main clinical signs noted in control and treated pups.

Dermal irritation (if dermal study):

not examined

Mortality / viability:

mortality observed, non-treatment-related

Description (incidence and severity):

Dead and/or missing pups were observed both in control and treated groups, with similar incidence.

Body weight and weight changes:

effects observed, non-treatment-related

Description (incidence and severity):

Reductions in mean litter weight and consequently in mean pup weight were evident in all litters of treated females on Day 13 post partum. Statistical significance was present in high dose females only for the mean litter weight and in low and high dose females for the mean pup weight. However, since the mean litter and pup weight values were within the historical control data, the changes in mean values were considered incidental and not treatment-related.

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

no effects observed

Description (incidence and severity):

No differences were recorded between control and treaded groups in thyroid hormones of pups sacrificed on Day 14 post partum.

Urinalysis findings:

not examined

Sexual maturation:

not examined

Anogenital distance (AGD):

effects observed, non-treatment-related

Description (incidence and severity):

No differences in the anogenital distance (normalised value) to the cube root of the body weight, performed on Day 1 post partum, were seen between control and treated groups for male pups. In female pups, a slight decrease, significant at statistical analysis, in the mean values was noted in low dose female pups when compared to the control value. However, since the mean value increment was not dose-related and values recorded for all treated female groups were within the historical control data, this finding was considered incidental and not treatment-related.

Nipple retention in male pups:

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Description (incidence and severity):

No relevant differences were noted in thyroid weight of pups between control and treated groups.

Gross pathological findings:

effects observed, non-treatment-related

Description (incidence and severity):

Decedent pups: autolysis of all organs were mainly observed in pups. No milk in stomach was noted in several pups belonging to the dams of the high-dose group. These findings were considered incidental and not treatment-related due to the single occurrence. No toxicologically relevant or treatment-related findings were recorded in pups sacrificed on Day 14 post partum.

Histopathological findings:

not examined

Other effects:

not examined

Behaviour (functional findings):

not examined

Developmental immunotoxicity:

not examined

Key result

Dose descriptor:

NOAEL

Remarks:

development

Generation:

F1

Effect level:

500 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

Additional data are provided under 'Attached background material' in the form of pdf documents.

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

500 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

The available information comprises an adequate and reliable (Klimisch score 1) study performed with the registered substance. The selected study is thus sufficient to fulfil the standard information requirements set out in Annexes VIII - X, Section 8.7, 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

Reproductive / developmental toxicity screening

The reproductive toxicity of isotridecanol, ethoxylated, < 2.5 EO (CAS No. 69011-36-5, EC No. 500-241-6) was tested in Sprague-Dawley rats in a reproductive / developmental toxicity screening test according to OECD guideline 421 under GLP conditions (Sasol/BASF, 2021c). Groups of 10 animals per sex received doses of 50, 150 and 500 mg/kg bw/day by daily oral gavage, 7 days a week for a minimum of 31 days. A control group was dosed with the vehicle (corn oil) only. Males were treated two weeks prior to pairing until the day before necropsy for a total of 31 days whereas females were treated for two weeks prior to pairing, during pairing, gestation and postpartum periods until Day 13 postpartum (for at least 51 days). One non-pregnant female, one that lost its litter and those showing no evidence of copulation were dosed up to the day before necropsy. The following parameters and  endpoints relevant for reproductive and developmental toxicity were recorded or measured: mortality, clinical signs, body weight, food consumption, oestrous cycle, mating performance, litter data, sex ratios, measurement of anogenital distance, blood collection for hormone assay (adult animals and pups), macroscopic observations and organ weights. Vaginal smears in all adult female groups were investigated at termination. Routine histopathological examination was performed in the first instance only on control and high dose groups. Since histopathological changes in the stomach were observed in high dose animals of both sexes, the examination of this organ was extended to low and mid-dose animals. The identification of the stages of the spermatogenic cycle was also performed in all males of the control and high dose groups. Thyroid hormone determination was performed in all adult males. Clinical signs observations were performed in all pups. Thyroid weight and thyroid hormone determination of 1/pup/sex/litter (where possible) at Day 14 postpartum were determined. All pups found dead in the cage were examined for external and internal abnormalities. Moreover, all culled pups sacrificed at Day 4 post partum and those sacrificed on Day 14 postpartum were subjected to an external examination and the sex was determined by internal gonads inspection.

The details of the results with respect to developmental toxicity are summarised below under 'Additional information' in the section for effects on developmental toxicity.

No mortality occurred throughout the study. One high-dose female was not pregnant at necropsy. One female of the mid- and one of the high-dose group did not mate and were found not pregnant at necropsy. In addition, one high-dose female lost its litter on Day 13 postpartum. The number of females with live pups on Day 14 postpartum was 10, 10, 9 and 7 in the control, low-dose (50 mg/kg bw/day), mid-dose (150 mg/kg bw/day) and high-dose group (500 mg/kg bw/day), respectively. In all high-dose males and in the majority of mid-dose males, salivation was generally observed during the treatment period although not continuously during the treatment. Three males of the low-dose group showed salivation only for a few days during the premating phase. In all females of the high-dose and in the majority of mid-dose females, salivation was sporadically observed during the treatment period. No clinical signs were observed during the study in females receiving 50 mg/kg b/day and in control females. This clinical sign (salivation) was considered treatment-related but not adverse. No relevant differences in body weight and body weight gain were noted between control and treated males throughout the study. In female animals, no differences of toxicological significance were noted in body weight before pairing. A statistically significant decrease in body weight (-8%) was seen at the end of the postpartum period in the high-dose group, compared with the control. Due to the low magnitude, this decrease was not considered adverse. In high-dose females, body weight gain was reduced at the beginning and at the end of the postpartum period. Food consumption recorded in male animals during the premating period was unaffected by treatment. A significant decrease (-12 to -22%) in food consumption was evident in all treated groups of female animals at the end of the postpartum period only, compared with the control. This is considered an incidental occurrence as it was only observed at one time point. No differences between control and treated males were recorded in thyroid hormones determination performed at the end of the study. Oestrous cycle, pre-coital intervals, copulatory index and fertility index did not show treatment-related effects. Furthermore, implantation, pre- and post-natal loss and gestation length were unaffected by treatment. A statistically significant decrease in terminal body weight was observed in high-dose treated females when compared to the controls. The reduction was approximately 8% compared with the control and therefore this decrease was not considered adverse. No relevant changes were observed in absolute and relative organ weights of treated animals, when compared to the controls. A statistically significant increase in absolute and relative mean liver weights was recorded in high-dose males. There were no associated histological changes and the weight increase is considered to be an adaptive effect and likely related to treatment. No other relevant changes were observed in absolute and relative organ weights of treated animals when compared to the controls. No treatment-related changes were noted following gross pathology examination. Treatment-related findings were seen in the stomach in mid- and high-dose groups of both sexes, consisting of epithelial hyperplasia of the non-glandular stomach. The epithelial hyperplasia was observed in 0/10, 0/10, 1/10 and 9/10 males, and 0/10, 0/10, 2/10 and 9/10 females in the control, 50, 150 and 500 mg/kg bw/day group, respectively. This finding was considered not relevant for humans due to the location (the non-glandular stomach in the rat is not present in humans). No other treatment-related changes were noted in animals sacrificed at the end of the treatment period. Regular layering in the germinal epithelium was noted in the seminiferous tubules of the control and high dose males.

Based on the results obtained in the study, the No Observed Adverse Effect Level (NOAEL) for general toxicity and for reproductive toxicity was considered to be 500 mg/kg bw/day for both sexes, i.e. the highest dose tested.

Extended one-generation reproductive toxicity study

According to Annex IX, Section 8.7.3, Column 1, of the REACH Regulation (EC) No. 1907/2006 an extended one-generation reproductive toxicity study (EOGRTS, OECD 443) must be performed if the available repeated dose toxicity studies (e.g. 28-day or 90-day studies, OECD 421 or 422 screening studies) indicate adverse effects on reproductive organs or tissues or reveal other concerns in relation to reproductive toxicity. The repeated dose toxicity as well as reproductive / developmental data available for isotridecanol, ethoxylated, < 2.5 EO (CAS No. 69011-36-5, EC No. 500-241-6) do not provide any concern in relation to reproductive toxicity. No toxicologically relevant effects were noted in reproductive organs and tissues.

It is, therefore, concluded that the triggers of Annex IX, Section 8.7.3, Column 1, of the REACH Regulation are not met and an EOGRTS is not required for isotridecanol, ethoxylated, < 2.5 EO (CAS No. 69011-36-5, EC No. 500-241-6).

Effects on developmental toxicity

Description of key information

Reproductive / developmental screening test (oral, rat, OECD 421): NOAEL (developmental toxicity) = 500 mg/kg bw/day

Conclusion based on data obtained with isotridecanol, ethoxylated, < 2.5 EO (CAS No. 69011-36-5, EC No. 500-241-6).

Pre-natal developmental study (oral, rat, OECD 414): NOAEL (maternal systemic toxicity) = 250 mg/kg bw/day, LOAEL (maternal systemic toxicity) = 750 mg/kg bw/day, NOAEL (developmental toxicity) = 750 mg/kg bw/day

Read-across based on data obtained with the analogue source substance 11-methyldodecan-1-ol (CAS No. 27458-92-0, EC No. 248-469-2).

Link to relevant study records

Reference

Endpoint:

developmental toxicity

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

Please refer to the Analogue Approach Justification provided in Section 13.

Reason / purpose for cross-reference:

read-across source

Species:

rat

Dose descriptor:

NOAEL

Remarks:

maternal

Effect level:

250 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

clinical biochemistry

clinical signs

food consumption and compound intake

organ weights and organ / body weight ratios

other: maternal toxicity

Remarks on result:

other: Source: CAS 27458-92-0, 2003, BASF, 30R0197/03011

Key result

Dose descriptor:

NOAEL

Effect level:

750 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: embryotoxicity

Remarks on result:

not determinable due to absence of adverse toxic effects

Remarks:

Source: CAS 27458-92-0, 2003, BASF, 30R0197/03011

Key result

Dose descriptor:

NOAEL

Effect level:

750 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: fetotoxicity

Key result

Dose descriptor:

NOAEL

Effect level:

750 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: teratogenicity

Key result

Abnormalities:

no effects observed

Key result

Developmental effects observed:

no

Conclusions:

No effect on intrauterine development or teratogenicity is predicted for the target substance based on an adequate analogue source substance.

Executive summary:

The prenatal developmental toxicity of the target substance is predicted based on an adequate and reliable prenatal developmental toxicity study of a structural analogue source substance. Treatment of pregnant rats with the test substance at 750 mg/kg bw/day induced a significant maternal toxic response in the form of transient salivation, urine smeared fur, reduced food consumption, increased alanine aminotransferase activities, decreased total protein and globulin concentrations, increased triglyceride levels and a statistically significant increase in absolute and relative liver weights. At 60 and 250 mg/kg bw/day, the test substance did not cause maternal toxicity. No effects on intrauterine development and no indication of teratogenicity was noted in either dosing group. Therefore, a lack of developmental toxicity and teratogenicity is prediced for the target substance. As explained in the analogue read-across justification, the differences in composition and molecular structure between the target and the source substances are unlikely to lead to differences in the developmental toxicity.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

750 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

The available information comprises adequate and reliable (Klimisch score 1) studies performed with the registered substance and with an analogue source substance with similar structures and intrinsic properties. Read-across is justified based on common toxicokinetic behaviour and consistent trends in toxicological properties of target and source substances. The selected studies are 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

Data on developmental toxicity for isotridecanol, ethoxylated, < 2.5 EO (CAS No. 69011-36-5, EC No. 500-241-6) are available from a screening study. However, no in-depth investigation of prenatal developmental toxicity is available. In order to assess prenatal developmental toxicity of the target substance, read-across from the analogue source substance 11-methyldodecan-1-ol (CAS No. 27458-92-0, EC No. 248-469-2) is applied in accordance with Annex XI, Section 1.5, of the REACH Regulation (EC) No. 1907/2006. Structural similarity and similarity with respect to toxicokinetic behaviour and toxicological properties and/or activities of the source and target substance are the basis of the read-across approach. A detailed justification of the analogue read-across approach is provided in IUCLID section 13.

Reproductive / developmental toxicity screening

As described under 'Additional information' in the section 'Effects on fertility' above, the reproductive and developmental toxicity of isotridecanol, ethoxylated, < 2.5 EO (CAS No. 69011-36-5, EC No. 500-241-6) was tested in Sprague-Dawley rats in a reproductive / developmental toxicity screening test according to OECD guideline 421 under GLP conditions (Sasol/BASF, 2021c). The experimental details of the study are summarised above. Only results relevant for developmental toxicity are provided here.

Litter data of treated females (total litter size, live litter size, pup loss, litter weight and mean pup weight) recorded at birth and on Days 1, 4 and 13 postpartum did not show treatment-related effects. Sex ratios at birth, on Days 4 and 14 postpartum did not show relevant differences between groups, when calculated as the percentage of males. There were no treatment-related clinical signs in the pups.. No nipples were found in male pups at Day 13 of lactation. No treatment-related effects were observed in anogenital distance measured in male and female pups of the treated groups. Necropsy findings in deceased pups and in pups sacrificed on Days 4 and 14 postpartum did not reveal any treatment-related effect. No relevant differences were noted in thyroid weight of pups between control and treated groups. No differences were recorded in thyroid hormone levels of pups sacrificed on Day 14 postpartum.

Based on the findings of this study, a No-Observed-Adverse-Effect-Level (NOAEL) of 500 mg/kg bw/day (i.e. the highest dose tested) for developmental toxicity was determined.

Prenatal developmental toxicity

Since the target substance contains a substantial amount of non-ethoxylated alcohol, i.e. isotridecanol, a developmental toxicity study (BASF, 2003) conducted with the pure alcohol 11-methyldodecan-1-ol (isotridecanol, CAS No. 27458-92-0, EC No. 248-469-2) is used in the analogue read-across approach. 11-Methyldodecan-1-ol (CAS No. 27458-92-0, EC No. 248-469-2) was administered to pregnant Wistar rats daily by stomach tube from implantation to one day prior to the expected day of parturition (Days 6-19 post coitum). Substance-related signs of maternal toxicity occurred at 750 mg/kg bw/day. The most obvious clinical effects on the high-dose dams were transient salivation in all dams immediately after treatment on certain days, urine smeared fur in four dams and statistically significantly reduced food consumption at initiation of treatment period (Days 6-10 post coitum). Regarding clinical pathology, statistically significantly increased alanine aminotransferase activities, decreased total protein and globulin concentrations, and increased triglyceride levels in the serum of the high-dose females were recorded. These changes, which were accompanied by statistically significantly increased absolute and relative liver weights (about 14% or 18%, respectively, above control values), are indicative for a mild adverse effect on the liver. The only substance-induced finding on the mid-dose dams (250 mg/kg bw/day) consisted in transitory salivation in 17 out of 25 rats, which, by itself and if seen in isolation, is not assessed as an adverse or toxic effect. No substance-induced effects on the dams occurred at the low-dose level (60 mg/kg bw/day). The oral administration of the test substance to the dams at all three dose levels (60, 250 and 750 mg/kg bw/day) had no influence on the gestational parameters. The following parameters were unaffected by treatment with the test substance: conception rate, mean number of corpora lutea, total implantations, resorptions and live foetuses, fetal sex ratio and the values calculated for the pre- and the post-implantation losses. No substance-related differences were recorded for placental and fetal body weights. The external, soft tissue and skeletal (including cartilage) examinations of the foetuses revealed no differences between the control and the substance-treated groups, which might be related to the test substance administration. Number and type of fetal external, soft tissue and skeletal findings, which were classified as malformations and/or variations, recorded for the 60, 250 and 750 mg/kg bw/day foetuses were unaffected by treatment. These findings appeared without a clear relation to dosing and/or were seen at incidences previously found to occur spontaneously in control foetuses of this strain of rats. Additionally, there was no specific malformation pattern, which could be indicative of a selective teratogenicity. Thus, the test substance induced no signs of prenatal developmental toxicity and in particular no indications for teratogenicity at dose levels up to and including 750 mg/kg bw/day.

Based on these results, the No-Observed-Adverse-Effect-Level (NOAEL) for maternal toxicity is 250 mg/kg bw/day, while it is 750 mg/kg bw/day for prenatal developmental toxicity.

Justification for classification or non-classification

The available data on reproductive and developmental toxicity obtained with isotridecanol, ethoxylated, < 2.5 EO (CAS No. 69011-36-5, EC No. 500-241-6) and with the analogue source substance 11-methyldodecan-1-ol (CAS No. 27458-92-0, EC No. 248-469-2) 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.