Registration Dossier

Administrative data

Description of key information

A 28-day, GLP, repeated dose oral toxicity study in rats conducted according to OECD test guideline 407 demonstrated a NOAEL of 200 mg/kg body weight/day for systemic toxicity of 1,4-butanediol diglycidylether. The same results were found in an OECD 422 study performed with 1,6-hexane diglycidylether. A sub-chronic OECD 408 study performed with 1,6-hexane diglycidylether has shown a NOAEL for systemic toxicity to be 300 mg/kg bw/d and this result can be used for read-across to the structural analogue 1,4-butanediol diglycidylether. Considering the slightly lower molecular weight of the 1,4-butanediol derivative, the NOAEL can be converted to 263 mg/kg bw/d on an equimolar basis.

Thus, it can be assumed that 1,4-butanediol diglycidylether is of low systemic toxicity in repeated-dose studies via oral application. Nevertheless, following a conservative approach, the results from the sub-acute oral toxicity study on 1,4-butanediol diglycidylether are used for DNEL derivation and risk assessment.

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Referenceopen allclose all

Endpoint:
short-term repeated dose toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2010
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Remarks:
Well documented, according to accepted guidelines.
Qualifier:
according to
Guideline:
OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity in Rodents)
Deviations:
yes
Remarks:
-sensory activity, grip strength, and motor activity assessments not performed
Qualifier:
according to
Guideline:
other: OPPTS Guideline 870.3050
Deviations:
not specified
GLP compliance:
yes
Limit test:
no
Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Laboratories, Inc., Raleigh, NC
- Age at study initiation: approximately 38 days old at receipt; 7 weeks old at the initiation of dose administration
- Weight at study initiation: 180 g to 220 g for males and from 154 g to 177 g for females at the time of randomization.
- Fasting period before study: Not reported
- Housing: housed individually in clean, stainless steel, wire-mesh cages suspended above cage-board
- Diet (e.g. ad libitum): PMI Nutrition International, LLC, Certified Rodent LabDiet® 5002, ad libitum
- Water (e.g. ad libitum): Reverse osmosis-treated (on-site) drinking water, delivered by an automatic watering system, ad libitum
- Acclimation period: 13 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21.3 to 22.2
- Humidity (%): 38.7 to 46.0
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12/12
Route of administration:
oral: gavage
Vehicle:
other: 0.5% carboxymethylcellulose in deionized water
Details on oral exposure:
PREPARATION OF DOSING SOLUTIONS: The vehicle suspension was prepared approximately weekly for administration to the control group (Group 1) and for preparation of the test substance formulations; aliquots were prepared for daily dispensation to the control group and stored refrigerated. The vehicle was mixed throughout preparation, sampling, and dose administration procedures.
The test substance formulations were weight/volume (test substance/vehicle) mixtures. The test substance formulations were prepared daily as single formulations for each dosage level and stored at room temperature. The test substance formulations were stirred continuously throughout the preparation, sampling, and dose administration procedures.

- Dosing volume: 10 mL/kg

VEHICLE
- Justification for use and choice of vehicle (if other than water): carboxymethylcellulose sodium, medium viscosity (No justification for use and choice of vehicle provided)
- Concentration in vehicle: 0, 2.5, 10.0, 20.0, and 40.0 mg/mL (test substance concentration)
- Lot/batch no. (if required): YM0461
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Prior to the initiation of dose administration (study day 0), quadruplicate samples (approximately 1 mL each) for homogeneity determination were collected from the top, middle, and bottom strata of the 2.5 and 40 mg/mL dosing formulations. Two of the quadruplicate samples collected from the middle strata for homogeneity determination were used for concentration determination. In addition, quadruplicate samples 10.0, and 20.0 mg/mL dosing formulations for concentration determination. On study days 7, 14, and 21, quadruplicate samples (approximately 1 mL each) for concentration determinations were collected from the middle strata of all dosing suspensions, including the control group. One duplicate set was analyzed and the remaining duplicate set was frozen (approximately -10 °C to -30 °C) and retained as backup samples. All analyses were conducted by the WIL Analytical Chemistry Department using a validated GC/MS method.
Duration of treatment / exposure:
28 days
Frequency of treatment:
Daily
Remarks:
Doses / Concentrations:
25, 100, 200, 400 mg/kg body weight/day
Basis:
actual ingested
No. of animals per sex per dose:
5 animals per sex per dose
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: Test substance dosing concentrations were selected by the Sponsor based on results from acute toxicity testing and were meant to cover a broad range of doses to evaluate toxicity.

The selected route of administration for this study was oral (gavage) because this is the route preferred for subchronic testing.
Positive control:
None
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Twice daily, once in the morning and once in the afternoon (for mortality and moribundity); twice daily, at the time of dose administration and approximately 1 to 2 hours following dose administration (clinical examination)
- Cage side observations checked: mortality and moribundity

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Weekly, beginning at least 1 week prior to test substance administration, at the time of randomization, and prior to the scheduled necropsy

BODY WEIGHT: Yes
- Time schedule for examinations: weekly, beginning at least 1 week prior to randomization.

FOOD CONSUMPTION:
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes

FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: No

WATER CONSUMPTION: No

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: at the scheduled necropsy (Week 4)
- Anaesthetic used for blood collection: Yes (isoflurane and carbon dioxide)
- Animals fasted: Yes
- How many animals: all animals
- Parameters checked: Total leukocyte count (WBC), erythrocyte count (RBC), hemoglobin (HGB), hematocrit (HCT), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), platelet count (PLATELET), prothrombin time (PT), activated partial thromboplastin time (APTT), reticulocyte count [percent (RETIC) and absolute (RETIC ABSOLUTE)], differential leukocyte count [percent and absolute, neutrophil (NEU), lymphocyte (LYMPH), monocyte (MONO), eosinophil (EOS), basophil (BASO), large unstained cell (LUC)], red cell distribution width (RDW), hemoglobin distribution width (HDW), platelet estimate, and red cell morphology (RBC Morphology)

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: at the scheduled necropsy (Week 4)
- Animals fasted: Yes
- How many animals: all animals
- Parameters checked: Albumin, total protein, globulin [by calculation], albumin/globulin ratio (A/G Ratio) [by calculation], total bilirubin (Total Bili), urea nitrogen, creatinine, alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma glutamyltransferase (GGT), glucose, total cholesterol (Cholesterol), calcium, chloride, phosphorus, potassium, sodium, triglycerides (Triglyceride), and sorbitol dehydrogenase (SDH)

URINALYSIS: Yes
- Time schedule for collection of urine: at the scheduled necropsy (Week 4)
- Metabolism cages used for collection of urine: Yes
- Animals fasted: Yes
- Parameters checked: Specific gravity (SG), pH, urobilinogen (URO), total volume (TVOL), color (COL), clarity (CLA), protein (PRO), glucose (GLU), ketones (KET), bilirubin (BIL), occult blood (BLD), leukocytes (LEU), nitrites (NIT), and microscopy of sediment

NEUROBEHAVIOURAL EXAMINATION: No
Sacrifice and pathology:
GROSS PATHOLOGY: Yes; The necropsies included, but were not limited to, examination of the external surface, all orifices, and the cranial, thoracic, abdominal, and pelvic cavities, including viscera.
HISTOPATHOLOGY: Yes; Adrenals (2), aorta, bone with marrow, femur, sternum, bone marrow smear (femur), brain, cerebrum level 1, cerebrum level 2, cerebellum with medulla/pons, cervix, epididymides (2), exorbital lacrimal glands (2), eyes with optic nerve (2), gastrointestinal tract, esophagus, stomach, duodenum, jejunum, ileum, cecum, colon, rectum, heart, kidneys (2), liver (sections of 2 lobes), lungs (including bronchi, fixed by inflation with fixative), lymph nodes, axillary (2), mandibular (2), mesenteric, nasal cavity, ovaries with oviducts (2), pancreas, peripheral nerve (sciatic), peyer’s patches, pharynx, pituitary, prostate, salivary glands (mandibular [2]), seminal vesicles with coagulating gland (2), skeletal muscle (rectus femoris), skin (with mammary gland), spinal cord (cervical, thoracic, lumbar), spleen, testes (2), thymus, thyroid (with parathyroids, if present [2]), trachea, Urinary bladder, uterus, vagina, gross lesions (when possible)

- The following organs were weighed from all animals at the scheduled necropsy: Adrenals, brain, epididymides, heart, kidneys, liver, ovaries with oviducts, prostate with seminal vesicles and coagulating glands, spleen, testes, thymus, thyroid with parathyroids, and uterus with cervix
Other examinations:
None
Statistics:
Each mean was presented with the standard deviation (S.D.), standard error (S.E.), and the number of animals (N) used to calculate the mean. Due to the different rounding conventions inherent in the types of software used, the means and standard deviations on the summary and individual tables may differ by ±1 in the last significant figure.

All statistical tests were performed using WTDMS™ unless otherwise noted. Analyses were conducted using two-tailed tests (except as noted otherwise) for minimum significance levels of 1% and 5%, comparing each test substance-treated group to the control group by sex.

Body weight, body weight change, food consumption, clinical pathology (except gamma glutamyltransferase), and organ weight data were subjected to a parametric one-way ANOVA (Snedecor and Cochran, 1980) to determine intergroup differences. If the ANOVA revealed statistically significant (p<0.05) intergroup variance, Dunnett's test (Dunnett, 1964) was used to compare the test substance-treated groups to the control group. Gamma glutamyltransferase values under range were assigned a value of 0.1 (half the lower limit of quantitation) for statistical analysis and reporting. Gamma glutamyltransferase data were subjected to the Kruskal-Wallis nonparametric ANOVA test (Kruskal and Wallis, 1952) to determine intergroup differences. If the ANOVA revealed significance (p<0.05), Dunn’s test (Dunn, 1964) was used to compare the test substance-treated groups to the control group.
Clinical signs:
effects observed, treatment-related
Mortality:
mortality observed, treatment-related
Body weight and weight changes:
effects observed, treatment-related
Food consumption and compound intake (if feeding study):
no effects observed
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
effects observed, treatment-related
Clinical biochemistry findings:
effects observed, treatment-related
Urinalysis findings:
no effects observed
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Gross pathological findings:
effects observed, treatment-related
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Histopathological findings: neoplastic:
not specified
Details on results:
CLINICAL SIGNS AND MORTALITY
Test substance-related wet clear material around the mouth was noted in the 200 and 400 mg/kg/day group males and females.

In the 400 mg/kg/day group males, wet clear material around the mouth was noted in 5/5 males at the time of dosing as early as study day 6 and in 5/5 males 1 to 2 hours following dose administration as early as study day 6. In the 400 mg/kg/day group females, wet clear material around the mouth was noted in 2/5 females at the time of the detailed physical examination on study day 14, in 5/5 females at the time of dosing as early as study day 5, and in 5/5 females 1 to 2 hours following dose administration as early as study day 8. This observation was noted throughout the dosing period in males and females, but to a lesser extent in females.

In the 200 mg/kg/day group males, wet clear material around the mouth was noted in 2/5 males at the time of dosing as early as study day 8 and in 3/5 males 1 to 2 hours following dose administration as early as study day 12. In general, the wet clear material around the mouth was observed throughout the dosing period. This clinical observation was also noted in the 200 mg/kg/day group females, but with fewer occurrences.

There were no other test substance-related clinical observations. All other clinical findings in the test substance-treated groups were noted with similar incidence in the control group, were limited to single animals, were not noted in a dose-related manner, and/or were common findings for laboratory rats of this age and strain.

BODY WEIGHT AND WEIGHT GAIN
Test substance-related effects on body weights were noted in the 400 mg/kg/day group males. Lower mean body weights, body weight gains, and cumulative body weight gains (occasionally significant compared to the control group) were noted throughout the dosing period.

Body weights were not affected in the 25, 100, and 200 mg/kg/day group males or in the 25, 100, 200, and 400 mg/kg/day group females.

FOOD CONSUMPTION
Food consumption was unaffected by test substance administration. There were no statistically significant differences when the control and test substance-treated groups were compared.

HAEMATOLOGY
Test substance-related higher mean absolute neutrophil, lymphocyte, monocyte, basophil, large unstained cell (LUC), and white blood cell counts were noted in the 400 mg/kg/day group males and/or females.

Statistically significantly higher mean absolute basophil counts were noted in the 400 mg/kg/day group males. Statistically significantly higher mean absolute neutrophil, lymphocyte, monocyte, and LUC counts, and consequently higher mean white blood cell counts were noted in the 400 mg/kg/day group males and females. These effects were considered to be test substance-related; however, all mean values were well within WIL historical control reference ranges (version 2.9), reference ranges are wide due to variability in these parameters, and individual values in this study were often variable as well.

There were no other test substance-related effects on hematology and coagulation parameters. Statistically significantly lower mean percent red cell distribution widths were noted in the 100 mg/kg/day group males and higher mean absolute reticulocyte counts were noted in the 400 mg/kg/day group females when the control and test substance-treated groups were compared; however, these differences were not considered test substance-related due to lack of a dose-response relationship, no correlating effects in red cell parameters, and mean values within WIL historical control reference range (version 2.9).

CLINICAL CHEMISTRY
Test substance-related alterations in serum chemistry parameters in the 400 mg/kg/day group males included lower mean globulin levels and subsequent higher A/G ratios, higher mean urea nitrogen values, higher mean alanine aminotransferase (ALT) values, and lower mean total protein values. Test substance-related higher triglyceride values were noted in the 400 mg/kg/day group females.

A statistically significantly higher mean A/G ratio was noted in the 400 mg/kg/day group males, and this value was above WIL historical control reference range (version 2.9). As the mean albumin value was similar to the control group, this ratio difference was associated with lower mean globulin levels. This difference from the control group value, while not statistically significant, was below the WIL historical control reference range (version 2.9). Mean total protein was also slightly lower in the 400 mg/kg/day group males when compared to the control group, although the difference lacked statistical significance. Statistically significant higher mean urea nitrogen and slightly higher mean alanine aminotransferase (ALT) values were also present in the 400 mg/kg/day group males. These effects were considered related to test substance administration.

Statistically significant higher triglycerides were noted in the 400 mg/kg/day group females. Though this effect was considered test substance-related, the mean value was within the WIL historical control reference ranges (version 2.9).

There were no other test substance-related effects on serum chemistry parameters. Statistically significantly lower total bilirubin values were noted in the 100 and 400 mg/kg/day group males; however, these differences were not considered to be test substance-related due to the lack of a dose-response trend, a high control group value (greater than the WIL historical control reference range [version 2.9]) being used for comparison, a toxicologically insignificant direction of change, and the mean values being within WIL historical control reference range (version 2.9). Statistically significantly higher chloride values were noted in the 400 mg/kg/day group males; however, this difference was not considered to be test substance-related due to the low magnitude of change, no effects noted on other electrolyte parameters, and the mean value being within WIL historical control reference range (version 2.9).

URINALYSIS
There were no test substance-related effects on urinalysis parameters. However, one statistically significant difference was observed when the control and test substance-treated groups were compared. Higher total urine volume in the 400 mg/kg/day group females was not considered to be test substance-related as there was no dose response, the magnitude of the difference was small, expected variability for this parameter is large, and the mean value was within WIL historical control reference range (version 2.9).

ORGAN WEIGHTS
Test substance-related lower final body weights were noted in the 400 mg/kg/day group males. Higher liver weights relative to body weights were noted in the 400 mg/kg/day group males and females and were considered related to test substance administration.

Statistically significantly lower final body weights were noted in the 400 mg/kg/day group males and were considered test substance-related. Mean liver weight relative to body weight differences were statistically significant in the 400 mg/kg/day group males and females when compared to the control group mean; due to final body weight differences in the males, only relative (to final body weight) values were employed as these values were considered to be more accurate in assessing a test substance-related effect. All mean values were within WIL historical control reference range (version 2.9), and there were no histologic correlates.
Statistically significantly higher brain weights relative to final body weights were noted in the 400 mg/kg/day group males; however, this difference was considered to be a result of the test substance-related effect on final body weight and, therefore, not directly related to test substance administration. There were no other test substance-related effects on organ weights. There were no test substance-related alterations in mean final body weight in the females.

GROSS PATHOLOGY
Thickened stomach was noted in the 400 mg/kg/day group males and females and was considered to be test substance-related due to correlation with histologic changes.

HISTOPATHOLOGY: NON-NEOPLASTIC
Test substance-related histologic alterations were observed in the stomach (nonglandular portion), exorbital lacrimal glands, and pancreas.

Hyperplasia of the stratified squamous epithelium of the nonglandular portion of the stomach was identified in 0/5, 1/5, 1/5, 3/5, and 5/5 males and 0/5, 0/5, 1/5, 4/5, and 4/5 females in the control, 25, 100, 200 and 400 mg/kg/day groups, respectively. This lesion correlated to gross observations of “thickened” stomach identified in both males and females in the 400 mg/kg/day group. At minimal to mild levels, a slight increase in keratin production was observed with only minimal hyperplasia of the underlying epithelial layers. At moderate to severe levels, rete peg formation, mucosal ridges, and remarkably increased keratin production were prominent. In 1 animal of each sex, associated submucosal edema and inflammation were also observed. The glandular stomach was unaffected.

Secretory depletion within the exorbital lacrimal glands was noted in 1/5, 1/5, 1/5, 2/5, and 3/5 males in the control, 25, 100, 200, and 400 mg/kg/day groups, respectively; this effect was absent in females. Given the similar incidence in the control, 25, and 100 mg/kg/day groups, this finding was considered an incidental background lesion in these animals, while secretory depletion was considered to be test substance-related in the 200 and 400 mg/kg/day groups based on a dose-responsive higher incidence and/or severity.

Zymogen depletion within the pancreas was observed in 1/5, 0/5, 1/5, 0/5, and 5/5 males and 1/5, 2/5, 2/5, 3/5, and 2/5 females in the control, 25, 100, 200, and 400 mg/kg/day groups, respectively. Based on incidence and severity, this finding was considered to be test substance-related in the 400 mg/kg/day group males. Although normal biological variability cannot be entirely excluded, based on the results of this study, zymogen depletion within the pancreas was considered to be test substance-related in the 25, 100, 200, and 400 mg/kg/day group females. The low number of animals per group complicated interpretation, particularly in the 25 mg/kg/dose group females. The relationship of this finding to the test substance was less apparent in the females. Although a single animal in the control group was minimally affected, a higher incidence was noted throughout the test substance-treated groups, with an increased severity in individuals in the 100 and 400 mg/kg/day dose groups. No dose response was observed.

Test substance-related zymogen depletion (mostly minimal to mild) noted in the pancreas of all test substance-treated females and 400 mg/kg/day group males, and secretory depletion of the exorbital lacrimal glands (minimal to mild) in the 200 and 400 mg/kg/day group males and females were of unknown toxicological significance and may represent a stress response.

There were no other test substance-related histopathologic changes. Histopathologic findings were considered to be incidental, manifestations of spontaneous diseases or related to some aspect of experimental manipulation other than exposure to the test substance. There was no test substance related alteration in the prevalence, severity, or histologic character of these incidental tissue alterations.
Dose descriptor:
NOAEL
Effect level:
200 mg/kg bw/day (actual dose received)
Sex:
male/female
Basis for effect level:
other: Based on lower body weights and body weight gains (males), as well as changes to hematological and clinical chemistry parameters and higher liver weights (both sexes).
Critical effects observed:
not specified

Test substance-related clinical findings were limited to wet clear material around the mouth noted in the 200 and 400 mg/kg/day males and females.

Test substance-related lower body weights, body weight gains, and cumulative body weight gains were noted in the 400 mg/kg/day group males throughout the dosing period. This effect was evident in subsequent test substance-related lower final body weights noted at the scheduled necropsy.

Test substance-related higher absolute neutrophil, lymphocyte, monocyte, basophil, large unstained cell (LUC), and consequent white blood cell counts were noted in the 400 mg/kg/day group males and/or females.

Test substance-related alterations in serum chemistry parameters in the 400 mg/kg/day group males included lower globulin levels and subsequent higher A/G ratios, higher urea nitrogen values, higher alanine aminotransferase (ALT) values, and lower total protein values. Test substance-related higher triglyceride values were noted in the 400 mg/kg/day group females.

Test substance-related higher liver weights (relative to body weight) were noted in the 400 mg/kg/day group males and females.

Test substance-related histologic changes included hyperplasia of the stratified squamous epithelium of the nonglandular stomach in the 25, 100, 200, and 400 mg/kg/day group males and the 100, 200, and 400 mg/kg/day females correlating to gross observations of “thickened” stomach in the 400 mg/kg/day group animals, secretory depletion in the exorbital lacrimal glands of the 200 and 400 mg/kg/day group males and females, and secretory depletion of zymogen granules in the pancreas of the 400 mg/kg/day group males and the 25, 100, 200, and 400 mg/kg/day group females. Findings of epithelial hyperplasia within the nonglandular stomach in this study are consistent with a local irritant effect of the test substance (GRILONIT RV 1806, MSDS No. 231053, 2010). Although this portion of the stomach (cardia) is comprised of keratinized stratified squamous epithelim in the rodent (Brown et al., 1990), the human stomach bears only glandular mucosa throughout (Burkitt et al., 1993). There were no histologic alterations of the glandular portion of the stomach of rats in this study.

Conclusions:
The NOAEL (oral, rat) in this sub-acute 28 day study for 1,4-butanediol diglycidyl ether was found being 200 mg/k bw/d.
Endpoint:
sub-chronic toxicity: oral
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study
Remarks:
Source study is Klimisch 1 but reduced liability due to read-across
Justification for type of information:
REPORTING FORMAT FOR THE ANALOGUE APPROACH
[Please provide information for all of the points below. Indicate if further information is included as attachment to the same record, or elsewhere in the dataset (insert links in 'Cross-reference' table)]

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
[Describe why the read-across can be performed (e.g. common functional group(s), common precursor(s)/breakdown product(s) or common mechanism(s) of action]
Please refer to the corresponding section in attached justification!

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
[Provide here, if relevant, additional information to that included in the Test material section of the source and target records]
Please refer to the corresponding section in attached justification!

3. ANALOGUE APPROACH JUSTIFICATION
[Summarise here based on available experimental data how these results verify that the read-across is justified]
Please refer to the corresponding section in attached justification!

4. DATA MATRIX
Please refer to the corresponding section in attached justification!
Reason / purpose:
read-across source
Qualifier:
according to
Guideline:
OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity in Rodents)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Limit test:
no
Clinical signs:
effects observed, non-treatment-related
Description (incidence and severity):
There were considered to be no clinical signs apparent that could be attributed to systemic toxicity of the test item. Instances of increased salivation were evident in all animals treated with 300 mg/kg bw/day and in all males treated with 100 mg/kg bw/day throughout the majority of the treatment period. Two females treated with 100 mg/kg bw/day also exhibited increased salivation but only on one occasion each during the study. Observations of this nature are commonly observed following the oral administration of an unpalatable or slightly irritant test item formulation and in isolation are generally considered to be of no toxicological importance. Other effects observed were considered incidental or reflecting difficulties in dosing.
Mortality:
no mortality observed
Description (incidence):
There were no unscheduled deaths.
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
Male animals treated with 300 mg/kg bw/day showed a reduction in body weight gain during the first week of treatment. Thereafter, slightly lower body weight gains were noted on some occasions during the treatment period, this resulted in an overall reduction in body weight gain when compared to control. Female animals from all treatment groups exhibited general reductions in body weight gain throughout the treatment period, however, true dose related responses were not evident. No such effects were noted in male animals treated with 30 or 100 mg/kg bw/day.
Food consumption and compound intake (if feeding study):
no effects observed
Description (incidence and severity):
No significant effects were detected in food consumption for treated animals of either sex.
Water consumption and compound intake (if drinking water study):
no effects observed
Description (incidence and severity):
Visual inspection of water bottles did not reveal any intergroup differences.
Ophthalmological findings:
no effects observed
Description (incidence and severity):
Ophthalmoscopic examination of animals of both sexes from the control and 300 mg/kg bw/day dose group during week 12 of the treatment period did not indicate any treatment-related differences.
Haematological findings:
no effects observed
Description (incidence and severity):
There were no toxicologically significant effects detected in the hematological parameters examined.
Clinical biochemistry findings:
no effects observed
Description (incidence and severity):
There were no toxicologically significant effects detected in the blood chemical parameters examined.
Behaviour (functional findings):
no effects observed
Description (incidence and severity):
There were no treatment-related changes in the behavioural parameters measured and no toxicologically significant changes in functional performance.
Organ weight findings including organ / body weight ratios:
effects observed, non-treatment-related
Description (incidence and severity):
Males and females treated with 300 mg/kg bw/day exhibited increases in absolute and relative liver weights. Females treated with 100 mg/kg bw/day showed a statistically significant reduction (p<0.05) in absolute liver weight but showed a statistically significant increase (p<0.05) in relative liver weight. These findings correlate with the hypertrophic changes noted in the liver during histopathological examination and are considered to be due to an adaptive response to treatment with the test item. Animals of either sex treated with 300 mg/kg bw/day showed statistically significant increases in absolute and relative kidney weight (p<0.01). Approximately 60% of control male animals, 90% of treated males, 30% of control females and 60% of treated females showed values that exceeded the normal control ranges. As there were no histopathological correlates to account for the effects on the kidneys, these findings are considered to be of no toxicological significance. No such effects were noted in male animals treated with 100 mg/kg bw/day or in animals of either sex treated with 30 mg/kg bw/day.
Gross pathological findings:
effects observed, non-treatment-related
Description (incidence and severity):
The following treatment related effects were noted in the stomachs of animals of either sex treated with 300 mg/kg bw/day: One male animal showed dark colored contents, all males and nine females exhibited raised white patches on the non-glandular region and nine males exhibited signs of sloughing and/or thickening of the non-glandular region or a raised limiting ridge. All other findings were without histopathological correlates and were considered to be incidental and not related to treatment with the test item; for details refer to source study.
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Description (incidence and severity):
The following treatment related effects were noted in the stomachs of animals of either sex treated with 300 mg/kg bw/day: One male animal showed dark colored contents, all males and nine females exhibited raised white patches on the non-glandular region and seven males exhibited signs of sloughing and/or thickening of the non-glandular region or a raised limiting ridge. All other findings were considered to be incidental and not related to treatment with the test item.
Liver: Centrilobular hepatocyte hypertrophy was noted in four males and four females treated with 300 mg/kg bw/day only.
Non Glandular Stomach: Ulceration or erosion was present in seven males and five females treated with 300 mg/kg bw/day.
Hyperplasia including hyperkeratosis, of moderate or marked severity, was present in all males treated with 300 mg/kg bw/day. Hyperplasia including hyperkeratosis, of mild or moderate severity, was noted in all females treated with 300 mg/kg bw/day.
No other findings were present at histopathology which could be attributed to treatment with the test item or correlated with in-life changes noted.
Details on results:
The oral administration of 1,6-hexanediol reaction product chloromethyloxirane to rats for a period of ninety consecutive days at dose levels of 30, 100 and 300 mg/kg bw/day resulted in treatment related effects in animals of either sex treated with 300 mg/kg bw/day and in female animals treated with 30 and 100 mg/kg bw/day.
Reductions in body weight gain were noted in male animals treated with 300 mg/kg bw/day during the first week of treatment. Thereafter, slightly lower body weight gains were noted on some occasions during the treatment period which resulted in an overall body weight gain which was approximately 16 % lower than controls. Female animals from all treatment groups exhibited general reductions in body weight gain throughout the treatment period. Overall body weight gains for all female treatment groups were approximately 15 % to 19 % lower than controls but were not in a dose related manner.
Although there were some statistically significant differences in treated animals from controls for the hematological and blood parameters measured, these differences were considered not to be of toxicological significance as the majority of values lay within the historical control data range and no histopathological correlates were apparent. A significant proportion of control data values also exceeded the historical control data and as such these findings were considered to be due to normal biological variation and not related to treatment of the test item.
Animals of either sex treated with 300 mg/kg bw/day exhibited increases in absolute and relative liver weights. Females treated with 100 mg/kg bw/day showed a reduction in absolute liver weight but showed a statistically significant increase (p<0.05) in relative liver weight. These findings correlate with the hypertrophic changes noted in the liver during histopathological examination and are considered to be due to an adaptive response to treatment with the test item.
Histopathological examination of the stomach revealed ulceration or erosion in the non-glandular region and was present in seven males and five females treated with 300 mg/kg bw/day. Hyperplasia including hyperkeratosis, of moderate or marked severity, was present in all males treated with 300 mg/kg bw/day and was noted at mild or moderate severity in all females from this dose group. These stomach findings could be considered an adverse effect as they point to an irritant effect of the test item on the non-glandular mucosa. However, these stomach findings are considered not to be relevant for humans as the unique structure of the rodent’s stomach is considered to lead to prolonged exposure to the test item and the corresponding anatomical area is not present in man. In terms of risk assessment, the findings observed on this study would suggest that a No Observed Adverse Effect Level (NOAEL) can be established at 300 mg/kg bw/day for animals of either sex because the findings in general do not reflect true systemic toxicity of the test item.
A No Observed Effect Level (NOEL) for systemic toxicity was considered to be 100 mg/kg bw/day for male animals; this could not be established in females due to the equivocal effect on body weight gain at 100 and 30 mg/kg bw/day.
Based on the read-across considerations presented above, these findings can be considered also representative for 1,4-butanediol, reaction product with 1-chloro-2,3-epoxypropane, the target substance for read-across, and the NOAEL, corrected at a molar level, is 263 mg/kg bw/d, accordingly.
Key result
Dose descriptor:
NOAEL
Effect level:
263 mg/kg bw/day (actual dose received)
Based on:
test mat.
Remarks:
corrected to target substance reflecting differences in molecular weight
Sex:
male/female
Basis for effect level:
other: A No Observed Adverse Effect Level (NOAEL) by the target substance was established at 300 mg/kg bw/day for animals of either sex because the findings in general did not reflect true systemic toxicity of the test item.
Key result
Critical effects observed:
no
Conclusions:
The oral administration of the read-across structural homologue 1,6-hexanediol reaction product with chloromethyloxirane to rats for a period of ninety consecutive days, to Wistar rats of both sexes at dose levels of 30, 100 or 300 mg/kg bw/day resulted in treatment related effects in animals of either sex treated with 300 mg/kg bw/day. A No Observed Effect Level (NOEL) for systemic toxicity was considered to be 100 mg/kg bw/day for male animals; this could not be established in females due to the slight body weight effects noted at 30 mg/kg bw/day. The microscopic liver change evident in animals of either sex treated with 300 mg/kg bw/day was considered to be an adaptive response to treatment and as such is considered to be non-adverse in nature. The stomach findings of ulceration or erosion and hyperplasia including hyperkeratosis (to varying degrees of severity) were noted in animals of either sex treated with 300 mg/kg bw/day and could be considered an adverse effect. However, these findings are likely to reflect an irritant effect of the test item on the non-glandular mucosa and are considered not to be relevant for humans as the unique structure of the rodent’s stomach is considered to have led to a prolonged exposure to the test item and the corresponding anatomical area is not present in man. In terms of risk assessment, the findings observed on this study would suggest that a No Observed Adverse Effect Level (NOAEL) can be established at 300 mg/kg bw/day for animals of either sex because the findings in general do not reflect true systemic toxicity. This NOAEL, corrected by molar weight, results in a NOAEL for 1,4-butanediol reaction product with chloromethyloxirane (1,4-butanediol, reaction product with 1-chloro-2,3-epoxypropane) of 263 mg/kg bw/d.
Executive summary:

Introduction

The study with the target substance 1,6-hexanediol reaction product with chloromethyloxirane was designed to investigate its systemic toxicity and is compatible with the OECD Guidelines for Testing of Chemicals No. 408 "Subchronic Oral Toxicity - Rodent: 90 Day Study” (Adopted 21 September 1998) and with Commission Regulation (EC) No 440/2008 of 30 May 2008, laying down test methods pursuant to Regulation (EC) No 1907/2006 of the European Parliament and of the Council on the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH).

Methods

The test item was administered by gavage to three groups, each of ten male and ten female Wistar Han™:RccHan™:WIST strain rats, for ninety consecutive days, at dose levels of 30, 100 and 300 mg/kg bw/day. A control group of ten males and ten females was dosed with vehicle alone (Arachis oil BP).

Clinical signs, functional observations, body weight change, dietary intake and water consumption were monitored during the study. Hematology and blood chemistry were evaluated for all animals at the end of the study. Ophthalmoscopic examination was also performed on control group and high dose animals.

All animals were subjected to gross necropsy examination and histopathological evaluation of selected tissues from all control and high dose animals (Groups 1 and 4) as well as any gross lesions from low and intermediate dose animals (Groups 2 and 3) was performed in the first instance. As there were treatment-related findings in the liver and stomach and equivocal changes in the thyroid, examination of these tissues was subsequently extended to include relevant animals from the low and intermediate dose groups.

Results

Mortality: There were no unscheduled deaths.

Clinical Observations: There were considered to be no clinical signs apparent that could be attributed to systemic toxicity of the test item.

Behavioral Assessment: There were no treatment-related changes in the behavioural parameters measured.

Functional Performance Tests: There were considered to be no toxicologically significant changes in functional performance.

Sensory Reactivity Assessments: There were no treatment-related changes in sensory reactivity.

Body Weight: Male animals treated with 300 mg/kg bw/day showed a reduction in body weight gain during the first week of treatment. Thereafter, slightly lower body weight gains were noted on some occasions during the treatment period, this resulted in an overall reduction in body weight gain when compared to control. Female animals from all treatment groups exhibited general reductions in body weight gain throughout the treatment period, however, true dose related responses were not evident. No such effects were noted in male animals treated with 30 or 100 mg/kg bw/day.

Food Consumption: No significant effects were detected in food consumption for treated animals of either sex.

Water Consumption: Visual inspection of water bottles did not reveal any intergroup differences.

Ophthalmoscopy: Ophthalmoscopic examination of animals of both sexes from the control and 300 mg/kg bw/day dose group during week 12 of the treatment period did not indicate any treatment-related differences.

Hematology: There were no toxicologically significant effects detected in the hematological parameters examined.

Blood Chemistry: There were no toxicologically significant effects detected in the blood chemical parameters examined.

Necropsy: The following treatment related effects were noted in the stomachs of animals of either sex treated with 300 mg/kg bw/day: One male animal showed dark colored contents, all males and nine females exhibited raised white patches on the non-glandular region and seven males exhibited signs of sloughing and/or thickening of the non-glandular region or a raised limiting ridge. All other findings were considered to be incidental and not related to treatment with the test item.

Organ Weights: Males and females treated with 300 mg/kg bw/day exhibited increases in absolute and relative liver weights. Females treated with 100 mg/kg bw/day showed a statistically significant reduction (p<0.05) in absolute liver weight but showed a statistically significant increase (p<0.05) in relative liver weight. No such effects were noted in male animals treated with 100 mg/kg bw/day or in animals of either sex treated with 30 mg/kg bw/day.

Histopathology

Liver: Centrilobular hepatocyte hypertrophy was noted in four males and four females treated with 300 mg/kg bw/day only.

Non Glandular Stomach: Ulceration or erosion was present in seven males and five females treated with 300 mg/kg bw/day.

Hyperplasia including hyperkeratosis, of moderate or marked severity, was present in all males treated with 300 mg/kg bw/day. Hyperplasia including hyperkeratosis, of mild or moderate severity, was noted in all females treated with 300 mg/kg bw/day.

No other findings were present at histopathology which could be attributed to treatment with the test item or correlated with in-life changes noted.

 

Conclusion

The oral administration of 1,6-hexanediol reaction product chloromethyloxirane to rats for a period of ninety consecutive days, to Wistar rats of both sexes at dose levels of 30, 100 or 300 mg/kg bw/day resulted in treatment related effects in animals of either sex treated with 300 mg/kg bw/day. A No Observed Effect Level (NOEL) for systemic toxicity was considered to be 100 mg/kg bw/day for male animals; this could not be established in females due to the slight body weight effects noted at 30 mg/kg bw/day. The microscopic liver change evident in animals of either sex treated with 300 mg/kg bw/day was considered to be an adaptive response to treatment and as such is considered to be non-adverse in nature. The stomach findings of ulceration or erosion and hyperplasia including hyperkeratosis (to varying degrees of severity) were noted in animals of either sex treated with 300 mg/kg bw/day and could be considered an adverse effect. However, these findings are likely to reflect an irritant effect of the test item on the non-glandular mucosa and are considered not to be relevant for humans as the unique structure of the rodent’s stomach is considered to have led to a prolonged exposure to the test item and the corresponding anatomical area is not present in man. In terms of risk assessment, the findings observed on this study would suggest that a No Observed Adverse Effect Level (NOAEL) can be established at 300 mg/kg bw/day for animals of either sex because the findings in general do not reflect true systemic toxicity.

Based on the read-across considerations presented above, these findings can be considered also representative for 1,4-butanediol, reaction product with 1-chloro-2,3-epoxypropane, the target substance for read-across, and the NOAEL, corrected at a molar level, is 263 mg/kg bw/d, accordingly.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEL
200 mg/kg bw/day
Study duration:
subacute
Species:
rat

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

The oral toxicity of butanediol diglycidylether was assessed in a 28-day, GLP study (Seidel, 2010) that was conducted according to OECD test guideline 407. Sprague Dawley rats (5/sex/group) were administered 1,4-butanediol diglycidylether by oral gavage for 28 consecutive days at 0 (vehicle control), 25, 100, 200, or 400 mg/kg body weight/day. The no-observed-adverse-effect level (NOAEL) for systemic toxicity was 200 mg/kg body weight/day. This level was based on lower body weights and body weight gains (males) as well as changes to hematological and clinical chemistry parameters and higher liver weights (both sexes) that were observed at the highest dose level of 400 mg/kg body weight/day. The NOAEL for local site of contact toxicity could not be established in males given the presence of hyperplasia of the stratified squamous epithelium of the non-glandular stomach at all doses. In females, the NOAEL for local site of contact toxicity was considered to be 25 mg/kg body weight/day on the basis of effects in the non-glandular stomach at ≥100 mg/kg body weight /day. Findings of epithelial hyperplasia within the non-glandular stomach in this study were reported by the authors to be consistent with a local irritant effect of the test substance. The observation of hyperplasia of the stratified squamous epithelium of the non-glandular stomach was considered by the authors to be a rodent-specific effect (i.e., not applicable to human exposure), since the human stomach consists of only glandular epithelia. There were no histologic alterations of the glandular portion of the stomach of rats in this study.

Similar results were found in an OECD 422 study performed with 1,6-hexane diglycidylether and therein also a NOAEL of 2000 mg/kg bw/d was derived. A sub-chronic OECD 408 study performed with 1,6-hexane diglycidylether has shown a NOAEL for systemic toxicity to be 300 mg/kg bw/d and this result can be used for read-across to the structural analogue 1,4-butanediol diglycidylether. Considering the slightly lower molecular weight of the 1,4-butanediol derivative, the NOAEL can be converted to 263 mg/kg bw/d on an equimolar basis.

Thus, it can be assumed that 1,4-butanediol diglycidylether is of low systemic toxicity in repeated-dose studies via oral application. Nevertheless, following a conservative approach, the result from the sub-acute oral toxicity study on 1,4-butanediol diglycidylether (NOAEL 200 mg/kg bw/d) is used for DNEL derivation and risk assessment.

Justification for classification or non-classification

Specific Target Organ Toxicity – Repeated Exposure: The notifiable substance did not exhibit significant toxic effects arising from a repeated exposure. As a result, the substance does not meet the criteria for classification according to Regulation (EC) No 1272/2008, Annex I section 3.9.