2,2'-(cyclohexylimino)bisethanol

Endpoint summary

Description of key information

Repeated oral administration of the submission substance at doses of 0, 12, 30 and 75 mg/kg body weight per day for 28 consecutive days to groups of 5 male and 5 female Wistar rats revealed no mortality and no clinical signs of intoxication. Additionally, no adverse effects were noted in functional observation battery, ophthalmoscopic, haematological or blood coagulation parameters. Body weight development was not impaired. Gross macroscopy and histopathology revealed no adverse effects. However, a preceding 14-day dose-range-finder study in rats revealed clinical effects, reduction in food intake and tendencies of reduced body weight gain as well as indications of altered organ weights and secondary inflammatory changes as evidenced by white blood cell counts at doses slightly above the highest dose tested in the main study. Based on all available data, the no-observed-adverse-effect level (NOAEL) of the test item with regard to repeated dose toxicity is considered to be equal or greater 75 mg/kg body weight per day.

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

February - July 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study according to GLP

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)

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Wistar rat, Crl: WI(Han) (SPF), Charles River, Germany
- Age at study initiation: 7-8 weeks (males); 7-8 weeks (females)
- Weight at study initiation: 132-178 g (males); 123-138 g (females)
- Fasting period before study: over night
- Housing: individual housing in IVC cages, type III H
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3 °C
- Humidity (%): 55 +/- 10 %
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12 hourd light / dark

Route of administration:

oral: gavage

Vehicle:

water

Analytical verification of doses or concentrations:

yes

Duration of treatment / exposure:

7 days/week, for 28 days

Frequency of treatment:

once daily

Remarks:

Doses / Concentrations:
0 mg/kg
Basis:
actual ingested

Remarks:

Doses / Concentrations:
12 mg/kg
Basis:
actual ingested

Remarks:

Doses / Concentrations:
30 mg/kg
Basis:
actual ingested

Remarks:

Doses / Concentrations:
75 mg/kg
Basis:
actual ingested

No. of animals per sex per dose:

5

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: based on 14 day dose-range finder
- Rationale for animal assignment (if not random): random
- Rationale for selecting satellite groups: n.a.
- Post-exposure recovery period in satellite groups: 14 days
- Section schedule rationale (if not random): random

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: daily

BODY WEIGHT: Yes
- Time schedule for examinations: at beginning of treatment and weekly thereafter

OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations:before tretament, last week of treatments, end of recovery period
- Dose groups that were examined: all animals

HAEMATOLOGY: Yes
- Time schedule for collection of blood: after last administration
- Anaesthetic used for blood collection: No
- Animals fasted: No
- How many animals: all surviving animals

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: after last administration
- Animals fasted: No
- How many animals: all surviving animls

URINALYSIS: Yes
- Time schedule for collection of urine: prior to sacrifice
- Metabolism cages used for collection of urine: No
- Animals fasted: No

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: once before first exposure and in forth week of exposure
- Dose groups that were examined: all animals
- Battery of functions tested: sensory activity / grip strength / motor activity / other: Functional observation battery

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes

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):

not examined

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

no effects observed

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

no effects observed

Behaviour (functional findings):

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

no effects observed

Details on results:

CLINICAL SIGNS AND MORTALITY
No mortality and no clinically signs

BODY WEIGHT AND WEIGHT GAIN
no effects on body weight development

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
no effect on food consumption and/or water intake

FOOD EFFICIENCY
n.a.

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study)
n.a.

OPHTHALMOSCOPIC EXAMINATION
no ophthalmoscopic findings

HAEMATOLOGY
no changes in haematological parameters

CLINICAL CHEMISTRY
all changes noted within range of historical controls

URINALYSIS
no changes in urinary parameters

NEUROBEHAVIOUR
no effects in FOB parameters noted

ORGAN WEIGHTS
no treatment related changes in organ weights

GROSS PATHOLOGY
no macroscopic findings

HISTOPATHOLOGY: NON-NEOPLASTIC
no treatment or test substance related histopathological changes

HISTOPATHOLOGY: NEOPLASTIC (if applicable)
n.a.

HISTORICAL CONTROL DATA (if applicable)
n.a.

Dose descriptor:

NOAEL

Effect level:

>= 75 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: overall effects

Critical effects observed:

not specified

Conclusions:

Based on the data of the present study, the no observed adverse effect level (NOAEL) of the test substance is equal or greater 75 mg/kg body weight per day.

Executive summary:

The test item was orally administered in graduated doses of 0, 12, 30 and 75 mg/kg body weight per day to 3 groups of male and female Wistar rats by oral gavage. One group receiving the vehicle sterile water served as control. The volume of application was 5 mL/kg body weight and the animals were dosed 7 days per week for a period of 28 days. No mortality and no clinical signs were recorded in any of the dose groups during the treatment period of this study. Additionally, no effects with clinical relevance were observed in any of the parameters of the functional battery testing and no ophthalmoscopic findings were noted. Body weight development and food intake were not affected. No relevant differences were found for haematological and blood coagulation parameters. Slight deviations in the clinical biochemistry parameters glucose, total protein, cholesterol and sodium in male or female treatment groups were within the range of historical controls. Additionally, deviation observed for relative weight (to terminal body weight) of kidney in female high dose group animals were not associated with histopathological findings and hence, were unlikely to be related to treatment. Based on the data generated the no observed adverse effect level (NOAEL) of Genamin CH 020 is considered to be equal or greater 75 mg/kg body weight per day.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

75 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

Guideline study according to GLP available. No derivations and/or confounders. Klimisch rating 1 representing reliability without restrictions. Information valid and meets data requirements with regard to hazard identification and classification.

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Quality of whole database:

Available data allows for route-to-route extrapolation.

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Quality of whole database:

Available data allows for expert judgement concerning this endpoint.

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Quality of whole database:

Available data allows for route-to-route extrapolation.

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Quality of whole database:

Available data allows for expert judgement concerning this endpoint.

Additional information

There are no human data available on repeated dose toxicity of the test item. Likewise no data from repeated dose studies are available for the inhalatory or dermal route of exposure. For the oral route of exposure information from a 14 -day dose-range-finder study as well as from a guideline compliant subacute 28 -day study is available.

In the 14 -day DRF mortality occurred at the high dose of 500 mg/kg body weight per day. Clinical signs of intoxication, tendencies of reduced food intake and body weight gain, and slightly altered organ weights were observed at the mid-dose of 125 mg/kg body weight. With regard to the corrosive nature of the test material, these effects may be regarded to be secondary due to irritative stress mediated by inflammatory changes as substantiated by differential blood cell count data.

In the 28-day oral toxicity study, doses up to 75 mg/kg body weight per day were devoid of any distinct adverse effect attributable to the treatment. There were no mortalities, no influence on food intake or body weight development and no clinical signs of intoxication. No relevant effetcs were observed in any parameter from the functional observation battery before and at the end of the treatment period. There were also no relevant differences in body temperature between the groups. Haematology, urinalysis and clinical chemistry revealed no statistical significant differences between treated and control animals. With regard to organ weights, there were slight deviations in the relative kidney weight in females from the high dose group. However, these were not considered to be treatment related since there were no structural and/or functional histopathological findings neither in the kidneys nor in any other organ evaluated. The no-observed-adverse-effect level (NOAEL) from this 28 -day oral toxicity study was considered to be 75 mg/kg body weight per day.

Justification for selection of repeated dose toxicity via oral route - systemic effects endpoint:
Guideline study according to GLP with a Klimisch rating of 1. Study design allows for endpoint related classification of substance

Repeated dose toxicity: via oral route - systemic effects (target organ) cardiovascular / hematological: other; digestive: stomach; digestive: other

Justification for classification or non-classification

The results from the available studies with repeated exposure of the submission substance indicate that the test material is systemically available following oral administration. Mortalities in male and female animals were observed at doses of 500 mg/kg body weight per day after approximately 6 - 8 days of dosing. Decrease in food intake was observed in male and female animals of the 500 mg/kg and 125 mg/kg dose groups in the first week of treatment. Haematological findings revealed increases in white blood cell count in male and females from these two higher dose groups as well as increased neutrophil counts in males and increased monocyte, eosinophil and baophil counts in females. These haematological findings are interpreted to be associated with inflammatory changes related to treatment. A possible explanation may be seen in the strong irritative / corrosive properties of the test material which may excert a cytotoxic potential at any site of contact, e.g. the mucosa of the gastrointestinal tract. The no-observed-adverse-effect level (NOAEL) from the subsequent 28 -day subacute oral toxicity study was established at 75 mg/kg body weight per day.

Based on ECHA guidance on the application of the CLP criteria (version 3.0), substances are classified as specific target organ toxicants following repeated exposure by the use of expert judgement on the basis of the weight of all evidence available, including the use of recommended guidance values. In this respect, the evidence from studies with repeated dose toxicity studies indicate that the submission substance has the potential to be harmful to human health following repeated exposure. Taking into account the guidance values as provided in annex 3.9.2.9.7 to Regulation (EC) No 1272/2008 (CLP), the respective dose range showing adverse health effects is indicative of a category 2 classification for the test item. Based on the extrapolated "equivalent" guidance values from 28 -day oral toxicity studies, the relevant dose range where adverse effects have to be seen is between 30 and 300 mg/kg body weight per day. The NOAEL for the test item identified in the 28 -day study is 75 mg/kg body weight per day.Taking into account that mortality was observed at 500 mg/kg body weight per day and at 125 mg/kg body weight per day significant changes in body weight development, organ weights and haematologial parameters occurred, the submission substance should be classified as

Xn; R48/22 Harmful: Danger of serious damage to health by prolonged exposure if swallowed (according to DSD)

Warning; STOT-RE Category 2 - H373: May cause damage to the gastrointestinal tract through prolonged or repeated

exposure via the oral route (according to CLP)

Inclusion of the inhalation route of exposure in the hazard statement according to CLP is not considered necessary, because of the very low vapour pressure of the submission substance and because the material is not a solid and thus exposure to dusts will not occur. In the unlikely event that the substance becomes airborne as an inhalable aerosol, the strong irritative properties of the submission substance will exhibite self-warning effects in the respiratory tract.

Inclusion of the dermal route of exposure in the hazard statement according to CLP is not considered necessary, because any dermal exposure has to be minimized due to strong irritative / corrosive properties of the submission substance and because the gastrointestinal tract is the primary target organ.