2-ethoxy-1,3-dimethylcyclohexane

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was conducted between 09 August 2016 and 23 August 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Reliability 1 is assigned because the study conducted according to OECD TG 402 in compliance with GLP, without deviations that influence the quality of the results.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

GLP compliance:

yes (incl. QA statement)

Test type:

fixed dose procedure

Limit test:

yes

Test material

Test material information

1

Reference substance name:

2-ethoxy-1,3-dimethylcyclohexane

EC Number:

944-610-3

Cas Number:

286472-48-8

Molecular formula:

C10H20O

IUPAC Name:

2-ethoxy-1,3-dimethylcyclohexane

Test material form:

liquid

Details on test material:

- Substance name as cited in test report: FRET 05-0293
- Phystical state: clear, colorless liquid
- Storage conditions: ambient temperature (15-25 °C), protected from light

Specific details on test material used for the study:

Identification: FRET 05-0293
Physical state/Appearance: clear colorless liquid
Expiry Date: 01 March 2018
Storage Conditions: room temperature in the dark

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Five male and five female Wistar (RccHan:WIST) strain rats were supplied by Envigo RMS (UK) Limited, Oxon, UK
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: 8 to 12 weeks of age
- Weight at study initiation: At the start of the study the animals weighed at least 200 g
- Fasting period before study: No
- Housing: The animals were housed in suspended solid floor polypropylene cages furnished with woodflakes. The animals were housed individually during the 24 Hour exposure period and in groups of five, by sex, for the remainder of the study.
- Diet and water (e.g. ad libitum): Free access to mains drinking water and food (2014C Teklad Global Rodent diet) was allowed throughout the study.
- Acclimation period: At least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): The temperature was set to achieve limits of 19 to 25 °C
- Humidity (%): The relative humidity was set to achieve limits of 30 to 70%
- Air changes (per hr): At least fifteen changes per hour
- Photoperiod (hrs dark / hrs light): Lighting was controlled by a time switch to give 12 hours continuous light and 12 hours darkness.

Administration / exposure

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

On the day before treatment the back and flanks of each animal were clipped free of hair.
Using available information on the toxicity of the test item, a single group of animals was treated as follows:

Dose level (mg/kg): 2000
Specific gravity: 0.840
Dose volume (mL/kg): 2.39
Number of rats: 5 Male / 5 female

The calculated volume of test item, as received, was applied as evenly as possible to an area of shorn skin (approximately 10% of the total body surface area) using a graduated syringe. A piece of surgical gauze was placed over the treatment area and semi occluded with a piece of self adhesive bandage. The animals were caged individually for the 24 Hour exposure period. Shortly after dosing the dressings were examined to ensure that they were securely in place.

After the 24 Hour contact period the bandage was carefully removed and the treated skin and surrounding hair wiped with cotton wool moistened with arachis oil BP to remove any residual test item. The animals were returned to group housing for the remainder of the study period.

Duration of exposure:

24 hours

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5 males and 5 females

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations: The animals were observed for deaths or overt signs of toxicity 30 minutes, 1, 2 and 4 hours after dosing and subsequently once daily for 14 day

- Evaluation of skin reactions: After removal of the dressings and subsequently once daily for 14 days, the test sites were examined for evidence of primary irritation and scored according to the following scale:

Erythema and Eschar Formation
No erythema (Value 0)
Very slight erythema (barely perceptible) (Value 1)
Well-defined erythema (Value 2)
Moderate to severe erythema (Value 3)
Severe erythema (beef redness) to slight eschar formation (injuries in depth) (Value 4)

Edema Formation
No edema (Value 0)
Very slight edema (barely perceptible) (Value 1)
Slight edema (edges of area well-defined by definite raising) (Value 2)
Moderate edema (raised approximately 1 millimeter) (Value 3)
Severe edema (raised more than 1 millimeter and extending beyond the area of exposure) (Value 4)

Any other skin reactions, if present were also recorded.

- Necropsy of survivors performed: yes, at the end of the study the animals were killed by cervical dislocation. All animals were subjected to gross necropsy. This consisted of an external examination and opening of the abdominal and thoracic cavities. The appearance of any macroscopic abnormalities was recorded. No tissues were retained.
- Body weights: Individual body weights were recorded prior to application of the test item on Day 0 and on Days 7 and 14.

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

There were no deaths

Clinical signs:

No signs of systemic toxicity were noted during the observation period.

Body weight:

All animals showed expected gains in body weight over the observation period.

Gross pathology:

No abnormalities were noted at necropsy.

Other findings:

Dermal reactions: There were no signs of dermal irritation.

Applicant's summary and conclusion

Interpretation of results:

other: Not classified according to CLP based on OECD TG No.402 study

Conclusions:

The acute dermal toxicity test showed an LD50 of greater than 2000 mg/kg bw.

Executive summary:

Acute dermal toxicity: In this study (conducted to OECD TG No.402), 10 rats (5 males and 5 females) were administered (single, 24 hour, semi-occluded dermal application) the substance at a dose level of 2000 mg/kg bw.

The rats showed no mortality, no clinical signs, no signs of dermal irritaiton, expected gains in body weight, no abnormalities at necropsy.

The acute dermal LD50 for the substance in male and female rats was determined to be greater than 2000 mg/kg bw