Ethane- 1,2-diol, propoxylated

Endpoint summary

Description of key information

Subacute (28-day) oral repeated dose toxicity (OECD 407): NOAEL (rat, f) = 1000 mg/kg bw/day, NOAEL (rat, m) = 300 mg/kg bw/day (based on effects on the spleen)

Subchronic (90-day) oral repeated dose toxicity (OECD 408): NOAEL (rat, m/f) = 1000 mg/kg bw/day

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Reference 1

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity Study in Rodents)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Ministerium für Arbeit, Gesundheit und Soziales des Landes Nordrhein-Westfalen, Düsseldorf, Germany

Limit test:

no

Species:

rat

Strain:

Wistar

Remarks:

Hsd Cpb:WU

Sex:

male/female

Route of administration:

oral: gavage

Vehicle:

other: Aqua dem.

Details on oral exposure:

The administration volume was 10 mL/kg bw/day. The formulations were prepared as needed and taking into account the analytically determined stability. For the preparation of the formulations the content of test item was assumed to be nominally 100% for calculation. The test item was administered as a solution in the vehicle. The formulations were stored at room temperature.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Before the start of treatment the stability of the formulations were analytically confirmed. For these analyses dosage forms were prepared in the same way as done in the study.
- Stability: The dosage forms prepared for analysis were analysed shortly after preparation (2 h) and 8 days thereafter. The analysis revealed that the test item was stable over this period within the defined limits.
- Content checks: For this purpose the test substance concentrations in formulations (including controls) given to the animals were determined two times during the study.

Duration of treatment / exposure:

29 days

Frequency of treatment:

once daily, 7 days/week

Dose / conc.:

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

Dose / conc.:

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

Dose / conc.:

1 000 mg/kg bw/day (actual dose received)

No. of animals per sex per dose:

5

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale:

In a two-week pilot study five animals per sex and dose received 100, 300 and 1000 mg/kg bw/day test substance. In-life data, necropsy, organ weight measurements and histopathology (stomach only) did not show any treatment-related changes up to 1000 mg/kg bw/day.

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

DETAILED CLINICAL OBSERVATIONS: Yes (incl. Open Field Observations (OFO))
- Time schedule: once before start and once weekly thereafter

BODY WEIGHT: Yes
- Time schedule for examinations: daily

FOOD CONSUMPTION: Yes
- Time schedule for examinations: weekly

WATER CONSUMPTION: Yes
- Time schedule for examinations: weekly

HAEMATOLOGY: Yes
- Time schedule for collection of blood: once, day 28
- How many animals: all dose groups incl. controls

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: once, day 28
- How many animals: all dose groups incl. controls

NEUROBEHAVIOURAL EXAMINATION: Yes
- Battery of functions tested: Functional Observational Battery (FOB); Motor Activity (MA)
- Time schedule for examinations: FOB: once, day 26 - 27; MA: once, day 21 - 22
- Dose groups that were examined: all dose groups incl. controls

Sacrifice and pathology:

GROSS PATHOLOGY: Yes (all dose groups and controls)

ORGAN Weights:
Adrenals, brain, epididymides, heart, kidneys, Liver, Ovaries, Spleen, Testes, Thymus, uterus, prostate, seminal vesicle with coagulation glands

Fixed organs:
Adrenals, aorta, brain (cerebrum, cerebellum, ponslmedulla), epididymides, esophagus, eyes, eyelids, extraorbital lachrymal glands, femur, harderian glands, head (with nasal and paranasal cavities), heart, intestine (duodenum, jejunum, ileum, cecum, colon, rectum and remaining intestine), kidneys, larynx, liver, lymph nodes (mandibular, bronchial/hilus, and mesenteric), lung, mamma, optical nerves, ovaries, oviducts, pancreas, pharynx, pituitary, prostate, salivary glands, sciatic nerve, seminal vesicles (incl. coagulating glands), skeletal muscle (thigh), skin (mammary and muzzle), spinal cord (cervical, thoracic, lumbar), spleen, sternum, stomach (forestomach and glandular stomach), testes, thymus, thyroids (including parathyroid glands), tongue, trachea, ureter, urethra, urinary bladder, uterus with uterine cervix, vagina, Zymbal’s glands and all organs or tissues with macroscopic findings.

HISTOPATHOLOGY: Yes (high dose group and controls)
- Microscopic: Adrenals, aorta, brain (cerebrum, cerebellum, brain stem), epididymides, eyes, femur, heart, intestine (duodenum, jejunum, ileum, cecum, colon, rectum and remaining intestine), kidneys, lung, ovaries, oviducts, prostate, sciatic nerve, skeletal muscle (thigh), spinal cord (cervical, thoracic, lumbar), sternum with bone marrow, testes, seminal vesicles (incl. coagulating glands), stomach, trachea and thyroids glands, urinary bladder, uterus with uterine cervix, vagina and all organs or tissues with macroscopic findings.

HISTOPATHOLOGY: Yes (all dose groups and controls)
-Microscopic: liver, lymph nodes, spleen, thymus

Statistics:

Statistical tests on body weights and weight gain as well as on absolute organ weights were done using the Dunnett Exact Homogeneous Test. For relative organ weights the Dunnett Exact Homogeneous Test after log. Transformation was used.
If primary food and water intake data were recorded, the calculated food/water intake per animal was evaluated using adjusted Mann-Whitney U-test.
The Dunnett Exact Homogeneous or Heterogeneous Test, the Dunnett Exact Homogeneous Test after log. Transformation or the Bonferroni/Mann-Whitney U-test was used for clinical pathology parameters.
Descriptive statistics were provided per sex, dose group and time point for all parameters that were recorded with a specified unit. These included measures of general tendency (mean, median) and general variability (standard deviation, minimum, maximum) as appropriate.
For continuous variables, the statistical test procedure was based on prior knowledge of the respective variable derived from previous studies. For normally distributed variables with equal variances across treatment groups Dunnett’s tests were performed. Heteroscedastic normally distributed variables were analysed using appropriately adjusted Dunnett’s tests, using Satterthwaite adjustments for the degrees of freedom and taking the different variances within the groups into account. For log-normally distributed variables, Dunnett's tests were performed after log-transformation of the original values. If experience with historical data indicated that the assumptions for parametric analyses are violated, Bonferroni-adjusted Mann-Whitney U-tests were employed in the analyses. For small sample sizes, the exact version of this test was used. With respect to data collected in the functional observational battery categorical variables were analyzed with a repeated measures analysis of variance followed by a one-way analysis of variance using the SAS procedure PROC CATMOD.

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not examined

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

no effects observed

Ophthalmological findings:

not examined

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

not examined

Behaviour (functional findings):

no effects observed

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Gross pathological findings:

effects observed, treatment-related

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Histopathological findings: neoplastic:

no effects observed

Details on results:

ORGAN WEIGHTS:
At 1000 mg/kg males exhibited higher means for liver (15-17%) and kidney (11-13%) weights (absolute and as % of terminal body weight). No other organ weight mean was remarkably or dose-dependently changed up to 1000 mg/kg.

GROSS PATHOLOGY:
Gross pathology revealed in the liver of some 1000 mg/kg males distinct lobulation (1/5, enlargement (1/5) or swelling (1/5). The thymus was enlarged in males at 300 mg/kg bw (1/5) and 1000 mg/kg (2/5), without histopathological correlate.

HISTOPATHOLOGY:
In the liver minimal to slight hepatocellular cytoplasmic change/hypertrophy was seen in 1000 mg/kg males (4/5, grade 1; 1/5, grade 2). In the absence of any other liver changes, this is not seen as an adverse effect. In the spleen increased germinal centers were present in the white pulp follicles of 1000 mg/kg males (1/5, grade 1; 3/5, grade 2). A treatment-relation could not be excluded for this finding.

Key result

Dose descriptor:

NOAEL

Effect level:

1 000 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

female

Basis for effect level:

other: no adverse effects observed

Dose descriptor:

NOAEL

Effect level:

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

Sex:

male

Basis for effect level:

other: microscopic changes in the spleen

Key result

Critical effects observed:

no

Due to the amount of supporting information, all data necessary to back-up the information reported in this endpoint study record are attached as pdf document under 'Attached background material'.

Executive summary:

{TO BE DELETED - identical text as in EPS:

In a repeated dose oral toxicity study in rats (Wistar, OECD TG 407), ethan-1,2 -diol, propoxylated was adimistered via gavage to 5 rats/sex/dose at 0, 100, 300, 1000 mg/kg bw for 4 weeks. Up to and including 1000 mg/kg bw no mortality occured. The behavior and clinical appearance of the rats were not influenced by the treatment up to and including 1000 mg/kg in both sexes. The body weight gain, the food and water intake were not affected up to and including 1000 mg/kg in males and females. The results from Functional Observational Battery (FOB) measurements in males and females receiving up to and including 1000 mg/kg bw did not differ from the control animals. Motor and Locomotor Activity(MA/LMA) tests did not indicate neurotoxicity up to and including 1000 mg/kg. No effects with toxiocological relevance in haematology in both sexes up to and including 1000 mg/kg bw. No remarkable changes occurred in clinical chemical parameters in the blood up to and including 1000 mg/kg in males and females. Gross pathology revealed in the liver of some 1000 mg/kg males distinct lobulation, enlargement or swelling and accordingly an increase in liver weights.

Histopathologically these findings correlated with minimal to slight hepatocellular cytoplasmic change/hypertrophy in the males of the 1000 mg/kg bw dose group. In the absence of any other liver changes, this is not seen as an adverse effect but as an adaptive response. In the spleen increased germinal centers were present in the white pulp follicles of 1000 mg/kg males. A treatment-relation could not be excluded for this finding.

Based on these results the NOAEL was considered to be 1000 mg/kg bw and day for females and 300 mg/kg bw and day for males due to the microscopic changes in the spleen }

Reference 2

Endpoint:

sub-chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15 Jan - 25 Sep 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity Study in Rodents)

Version / remarks:

adopted Jun 2018

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.26 (Sub-Chronic Oral Toxicity Test: Repeated Dose 90-Day Oral Toxicity Study in Rodents)

Version / remarks:

adopted May 2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.3100 (90-Day Oral Toxicity in Rodents)

Version / remarks:

adopted Aug 1998

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

The Department of Health of the Government of the United Kingdom, Medicines & Healthcare Products Regulatory Agency, UK

Limit test:

no

Specific details on test material used for the study:

Batch no.: VOEL 115 Pt. 1

Species:

rat

Strain:

Wistar

Remarks:

Crl:WI(Han)

Details on species / strain selection:

The species and strain chosen are the accepted rodent species and strain for nonclinical toxicity testing by regulatory agencies.

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Envigo RMS (UK) Limited, Oxon, UK
- Age at study initiation: 8 weeks
- Weight at study initiation: 210 - 273 g (males) and 149 - 188 g (females)
- Housing: Up to 3 animals of each sex per dosing group in polycarbonate cages with stainless steel grid tops and solid bottoms; appropriate bedding was provided.
- Diet: Special Diet Services Rat and Mouse No. 1 Diet SQC, ad libitum; supplier: Special Diet Services, Witham, England
- Water: Public tap water, ad libitum
- Acclimation period: 16 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 - 24
- Humidity (%): 32 - 71
- Air changes (per hr): >= 10
- Photoperiod (hrs dark / hrs light): 12 / 12

IN-LIFE DATES: From: To:15 Jan - 23 Apr 2020

Route of administration:

oral: gavage

Details on route of administration:

The oral (gavage) route of exposure was selected because it is accepted to be the most appropriate route of administration for this kind of study.

Vehicle:

water

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS:
Dosing solutions were prepared weekly by dissolving appropriate amounts of the test material in water yielding a final concentrations of 10, 30 and 100 mg/mL.

VEHICLE
- Concentration of test substance in vehicle: 10, 30 and 100 mg/mL
- Dose volume: 10 mL/kg bw
- Lot/batch no.: Not applicable, continously prepared by a Mili-Q system

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Dosing formulations were analysed for concentration, homogeneity and stability by gas chromatography (GC) with flame ionisation detection (FID) using a validated analytical procedure (Oxenham, 2020, study 424104). Concentration and homogeneity determinations yielded acceptable results (for concentration: mean sample concentration results within or equal to ± 15% of theoretical concentration, each individual sample concentration result within or equal to ± 20%; for homogeneity: relative standard deviation (RSD) of concentrations of <= 10% for each group). The stability analyses performed demonstrated that the test substance is stable in the vehicle.

Duration of treatment / exposure:

at least 90 days

Frequency of treatment:

once daily, 7 days/week

Dose / conc.:

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

Dose / conc.:

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

Dose / conc.:

1 000 mg/kg bw/day (actual dose received)

No. of animals per sex per dose:

10

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: Dose levels were based on the results of a foregoing range finding study, in which animals were orally exposed to 100, 300 and 1000 mg/kg bw/day for 28 days. At 1000 mg/kg
bw/day, germinal centers in the white pulp follicles of the spleen were increased in males. This finding was assessed to be non-adverse. Females were not affected. Therefore, 100, 300 and 1000 mg/kg bw/day were selected as the dose levels for the main study.
- Fasting period before blood sampling for clinical biochemistry: Overnight with a maximum of 24 h

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS, MORTALITY AND POSTDOSE OBSERVATIONS: Yes
- Time schedule: At least once daily before animals were dosed, beginning in the week before dosing commenced.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Weekly, from the week before dosing commenced and throughout the study.

BODY WEIGHT: Yes
- Time schedule for examinations: Weekly, from the week before dosing commenced and throughout the study.

FOOD CONSUMPTION:
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: No, food consumption determined at least weekly, from the week before dosing commenced and throughout the study, quantitatively measured per cage.

WATER CONSUMPTION: Yes
- Time schedule for examinations: Checked on regular basis throughout the study, monitored by visual inspection of the water bottles.

OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule and dose groups for examinations: Pretreatment: once (all animals), dosing period: week 13 (all animals of control and high-dose groups).

HAEMATOLOGY: Yes
- Time schedule for collection of blood: At termination of study.
- Anaesthetic used for blood collection: Yes (isofluorane).
- Animals fasted: Yes (overnight, max. 24 h).
- How many animals: All
- Parameters examined: Red blood cell count, hemoglobin concentration, hematocrit, mean corpuscular volume, red blood cell distribution width, mean corpuscular hemoglobin concentration, mean corpuscular hemoglobin, reticulocyte count (absolute), platelet count, white blood cell count, neutrophil count (absolute), lymphocyte count (absolute), monocyte count (absolute), eosinophil count (absolute), basophil count (absolute), large unstained cells (absolute), other cells (as appropriate).

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: At termination of study.
- Animals fasted: Yes (overnight, max. 24 h).
- How many animals: All
- Parameters examined: Alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, gamma-glutamyltransferase, creatine kinase, total bilirubin, urea, creatinine, calcium, phosphate, blood urea nitrogen (BUN), total protein, albumin, globulin (calculated), albumin/globulin ratio, glucose, total Cholesterol, HDL and LDL cholesterol, triglycerides, sodium, potassium, chloride.

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule and dose groups for examinations: Once during the dosing period, 5 animals per sex per group in Week 13.
- Battery of functions tested: sensory activity / grip strength / motor activity / pain perception / landing foot splay.

IMMUNOLOGY: No

OTHER:
- Detailed Functional Observations: Once during pretreatment and once weekly during the dosing period for all animals, incl. posture/condition on first approach (animal undisturbed), checking prostration, sterotypy / bizarre behaviour, tremors (head, limbs, whole body), convulsions, ease of removal from the cage, body temperature, rectal temperature, condition of the eyes, body tone. pinna response, presence of salivation, overall ease of handling, respiration rate and pattern, air righting, extensor thrust, observations in a standardised arena (2 min observation period).
- Monitoring of Estrous Cycle: Vaginal smears of all females were examined on the morning of necropsy.
- Thyroid hormones: TSH, T3 and T4 (on morning of necropsy after overnight fasting on all animals).

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
- Organs and tissues: Artery (aorta), body cavity (nasal), bone marrow (sternum), bone marrow smear, bone (sternum), brain, epididymides, esophagus, eye, ganglion (dorsal root, lumbar), glands (adrenal, clitoral, lacrimal, Harderian, mammary, parathyroid, pituitary, preputial, prostate, salivary (submandibular, sublingual and parotid), seminal vesicle, thyroid, Zymbal’s), gut-associated lymphoid tissue, heart, kidney, large intestine (cecum, colon and rectum), larynx, liver, lung, lymph node (mandibular and mesenteric), skeletal muscle, nerve (optic, sciatic and tibial), ovary, oviduct, pancreas, skin, small intestine (duodenum, ilium and jejunum), spinal cord, spleen, stomach, testis, thymus, tongue, trachea, ureter, urinary bladder, uterus/cervix, vagina

HISTOPATHOLOGY: Yes
- Like above EXCEPT: Bone marrow smear, ganglion (dorsal root, lumbar), glands (clitoral, lacrimal, Harderian, preputial, salivary, Zymbal's), nerve (tibial), oviduct, ureter

Other examinations:

Monitoring of Estrous Cycle: Vaginal smears on all females were examined on the morning of necropsy to determine the stage of estrous cycle to allow correlation with histopathology of ovaries.

Sperm Evaluation:
- Computer-aided sperm assessment (CASA): All males, an appropriate sperm suspension was examined using a Hamilton Thorne sperm motility analyser
- Sperm count and morphological analysis: Sperm suspension were counted using a haemocytometer, a total sperm count expressed per cauda epididymis and per gram of cauda epididymis was obtained; a sperm smear was prepared and stained with eosin Y solution, from the control and high-dose group males at least 200 sperm per animal were evaluated for morphological abnormalities
- Spermatid count: A suspension was prepared by homogenising the right testes, the number of homogenisation-resistant spermatids were counted using a haemocytometer to obtain a total spermatid count expressed per testis and per gram of testis

Statistics:

Constructed Variables:
Body Weight Gains: Calculated between each scheduled interval
Organ Weight Relative to Body Weight: Calculated against the terminal body weight
Organ Weight Relative to Brain Weight: Calculated against the brain weight

Descriptive Statistical Analyses:
Means, standard deviations, percentages, numbers, and/or incidences have been reported as appropriate by dataset.

Inferential Statistical Methods:
All statistical tests were conducted at the 5% significance level. All pairwise comparisons were conducted using two sided tests and have been reported at the 1% and 5% levels.

Parametric/Non-parametric
Levene’s test was used to assess the homogeneity of group variances. The groups were compared using an overall one-way ANOVA F-test if Levene’s test was not significant or the Kruskal-Wallis test if it was significant. If the overall F-test or Kruskal-Wallis test was found to be significant, then pairwise comparisons were conducted using Dunnett’s or Dunn’s test, respectively. Datasets with two groups were compared using a Dunnett’s test (equivalent to t-test in Nevis 2012 tables) or Dunn’s test (equivalent to Wilcoxon Rank-Sum test in Nevis 2012 tables).

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not examined

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

no effects observed

Ophthalmological findings:

no effects observed

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

Increased white blood cell count (neutrophils, lymphocytes, monocytes and basophils) and red blood cell index (red blood cell count, haemoglobin and haematocrit) in females at 1000 mg/kg bw/day, non-adverse.

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

Increased cholesterol (incl. high-density lipoproteins and low-density lipoproteins) in males at 1000 mg/kg bw/day (2.252 mmol/L vs. 1.687 mmol/L in the control), non-adverse.
Increased T3 in females of all dose groups, non-adverse.

Urinalysis findings:

not examined

Behaviour (functional findings):

no effects observed

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

Increased liver weights in treated animals at 1000 mg/kg bw/day in the percentage body weight analysis (males and females) and the absolute analysis (males), non-adverse.
Slightly higher absolute thyroid gland weights in males of all dose groups (statistically significance at 300 and 1000 mg/kg bw/day), no correlating histopathological changes found, relationship to treatment cannot be assessed with any certainty, finding remains of equivocal toxicological significance.

Gross pathological findings:

no effects observed

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

not examined

Other effects:

no effects observed

Description (incidence and severity):

No effects were observed on oestrus cycle and sperm analysis.

Details on results:

Mortality:
There were no premature deaths.

Clinical observations:
There were no treatment-related clinical observations.

Food consumption and body weight development:
There were no treatment-related changes in food consumption and body weight or body weight gain.

Ophthalmologic examinations:
There were no ophthalmologic findings considered to be treatment-related.

Functional observational battery and motor activity:
There were no quantitative or qualitative functional observations or motor activity findings considered to be treatment-related. All differences, including those that were statistically significant, were considered within normal biological variation, and/or were similar to control values and were considered unrelated to the treatment.

Oestrus cycle:
Oestrus cyclicity was not affected by treatment.

Sperm and spermatid analysis:
No effects were observed in the sperm analysis. The individual spermatid count per testis was slightly lower than controls in males dosed at 1000 mg/kg bw/day (93 x10E6 compared to 110 x10E6 in the controls). However, this difference was without any statistical significance, values were within historical control data and were not biologically relevant. Therefore, this finding was considered not treatment-related.

Haematology:
The white blood cell count (mainly attributed to neutrophils, lymphocytes, monocytes and basophils) and red blood cell index (red blood cell count, hemoglobin and hematocrit), were higher in females dosed at 1000 mg/kg bw/day, reaching statistical significance in the red blood cell count and haematocrit values, when compared with controls. The differences was slight and/or there was no dose dependent relationship, values were within historical control data and there was no evidence of correlating histopathological changes. These findings were, therefore, considered non-adverse.

Clinical chemistry:
Cholesterol (including high-density lipoproteins and low-density lipoproteins) was statistically significantly increased in males (2.252 mmol/L compared to 1.687 mmol/L in the control) dosed at 1000 mg/kg bw/day. The differences were slight and/or values were within historical control data and there was no evidence of correlating histopathological changes. These findings were, therefore, considered non-adverse.

Thyroid hormone analysis:
Triiodothyronine (T3) was found to be increased in females of all dose groups, when compared with controls. Due to the lack of dose-dependency and associated histopathological changes in the thyroid, these findings were considered non-adverse. There were no other changes in the thyroid hormones considered to be related to treatment.

Gross pathology:
There were no gross findings which could be associated with treatment. All findings were of the nature commonly observed in this strain and age of rat or occurred at a similar incidence in control and treated animals.

Organ weights:
Slightly increased liver weights were noted in males and females when dosed at 1000 mg/kg bw/day with the test subsgtance. In the absence of any correlating microscopic findings or liver enzyme changes, this was considered an adaptive change and therefore non-adverse. There were individual organ weight values that were different from their respective controls. There were, however, no patterns or correlating data (taking into account differences in sexual maturity) to suggest these values were test substance-related. In addition, there were slighty increased absolute thyroid gland weights noted in males of all treatment groups reaching statistical significance at 300 or 1000 mg/kg bw/day. However, there was no dose-response relationship. The thyroid gland weights were decreased in females when compared to controls, demonstrating the opposite trend to that seen in males. As there was no evidence of correlating histopathological changes found in the thyroid, a relationship to treatment cannot be made with any certainty and the higher thyroid weight in males remains of equivocal toxicological significance.

Histopathology:
There were no microscopic findings which could associated with the treatment. All findings were of the nature commonly observed in this strain and age of rat, or occurred at a similar incidence in control and treated animals.

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 adverse effects observed

Key result

Critical effects observed:

no

Due to the amount of supporting information, all data necessary to back-up the information reported in this endpoint study record are attached as pdf document under 'Attached background material'.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 000 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Quality of whole database:

The available information comprises adequate and reliable subacute and subchronic studies (both Klimisch score 1) performed with the registered substance. The selected studies are thus sufficient to fulfil the standard information requirements set out in Annexes VIII - X, Section 8.6, of Regulation (EC) No. 1907/2006 (REACH).

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Short-term (28-day)

In a short-term repeated dose oral toxicity study in Han Wistar rats performed under GLP conditions and according to OECD guideline 407, ethan-1,2 -diol, propoxylated (CAS No.31923-84-9, EC No. 500-078-0) was adimistered via gavage to 5 rats/sex and dose at 100, 300 and 1000 mg/kg bw/day for 4 weeks (rel 1-key, rat, gavage, 28d, OECD 407, Bayer Schering Pharma, 2010a, T7080702). Control animals received the vehicle (aqua dem.). Up to and including 1000 mg/kg bw/day no mortality occured. The behaviour and clinical appearance of the rats were not influenced by the treatment up to and including 1000 mg/kg bw/day in both sexes. The body weight gain, the food and water intake were not affected up to and including 1000 mg/kg bw/day in males and females. The results from Functional Observational Battery (FOB) measurements in males and females receiving up to and including 1000 mg/kg bw/day did not differ from the control animals. Motor and Locomotor Activity (MA/LMA) tests did not indicate neurotoxicity up to and including the top dose. No effects of toxiocological relevance in haematology in both sexes up to and including 1000 mg/kg bw/day were observed. No remarkable changes occurred in clinical chemical parameters in the blood up to and including the highest dose tested in males and females. Gross pathology revealed in the liver of some males receiving 1000 mg/kg bw/day distinct lobulation, enlargement or swelling and accordingly an increase in liver weights. Histopathologically these findings correlated with minimal to slight hepatocellular cytoplasmic change/hypertrophy. In the absence of any other liver changes, this is not seen as an adverse effect but as an adaptive response. In the spleen increased germinal centers were present in the white pulp follicles of 1000 mg/kg bw/day males. A relation to the treatment with the test substance could not be excluded for this finding. Its biological relevance remained unclear. Based on these results the no-observed-adverse-effect level (NOAEL) was considered to be 1000 mg/kg bw/day for females and 300 mg/kg bw/day for males due to the microscopic changes in the spleen.

Subchronic (90-day)

The subchronic oral repeated dose toxicity of ethane-1,2-diol, propoxylated (CAS No. 31923-84-9, EC No. 500-078-0) was investigated in a study conducted according to OECD guideline 408 under GLP conditions (rel 1-key, rat, gavage, 90d, OECD 408, Charles River, 2020, 510622). Groups of 10 Han Wistar rats per sex were administered the test substance by oral gavage for at least 90 consecutive days at doses of 100, 300 and 1000 mg/kg bw/day. The control group received the vehicle (water). The following parameters were evaluated: clinical signs, body weights, food consumption, ophthalmology, detailed functional observations, estrous cycles, sperm evaluation, clinical parameters (haematology, coagulation, clinical chemistry and thyroid hormone analysis), gross necropsy findings, organ weights and histopathological examinations. All animals survived until scheduled necropsy. There were no clinical observations, changes in bodyweight, food consumption, ophthalmologic findings, functional observations, motor activity, estrous cycle, sperm analysis, gross necropsy or microscopic observations considered to be related to the administration of test substance. Non-adverse changes in the white blood cell count and red blood cell index were noted in females dosed at 1000 mg/kg bw/day, in cholesterol levels in males dosed at 1000 mg/kg bw/day and in T3 levels in all treated females. There were slightly increased thyroid gland weights noted in all males treated with the test substance. This finding was considered to be of equivocal toxicological significance and a relationship to treatment could not be made with any certainty. In addition, slightly increased liver weights were found in males and females of the high-dose group (1000 mg/kg bw/day). This finding was not correlated with any microscopic changes and, therefore, considered non-adverse. In conclusion, administration of ethane-1,2-diol, propoxylated by once daily oral gavage for 90 days was well tolerated in rats at levels of up to 1000 mg/kg bw/day. Based on these results, the no-observed-adverse-effect level (NOAEL) was considered to be 1000 mg/kg bw/day for both male and female rats.

Conclusion on repeated dose toxicity

The histopathological changes in the spleen of male animals dosed at 1000 mg/kg bw/day with ethane-1,2-diol, propoxylated which were observed in the short-term (28-day) repeated dose toxicity study could not be confirmed in the subchronic (90-day) study. No effects on the spleen of either male or female animals of any treatment group was apparent in the subchronic study. Since the subchronic study uses the longer exposure period, the no-observed-adverse-effect level (NOAEL) of 1000 mg/kg bw/day for male and female rats determined in this study is taken forward to the hazard assessment, determination of the classification and labelling and the risk assessment.

Justification for classification or non-classification

The available data on subacute and subchronic repeated dose toxicity with ethane-1,2-diol, propoxylated (CAS No.31923-84-9, EC No. 500-078-0) do not meet the criteria for classification according to Regulation (EC) No. 1272/2008 (CLP) and are therefore conclusive but not sufficient for classification.