4-isopropyl-1-methylcyclohexene

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Remarks:

OECD No.420 (2001) "Acute Oral Toxicity, Fixed Dose Procedure"

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 420 (Acute Oral Toxicity - Fixed Dose Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

fixed dose procedure

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

4-isopropyl-1-methylcyclohexene

EC Number:

226-841-5

EC Name:

4-isopropyl-1-methylcyclohexene

Cas Number:

5502-88-5

Molecular formula:

C10H18

IUPAC Name:

1-methyl-4-(propan-2-yl)cyclohex-1-ene

impurity 1

Reference substance name:

rel-(1R,4R)-1-isopropyl-4-methylcyclohexane

Cas Number:

1678-82-6

Molecular formula:

C10H20

IUPAC Name:

rel-(1R,4R)-1-isopropyl-4-methylcyclohexane

impurity 2

Reference substance name:

rel-(1S,4S)-1-isopropyl-4-methylcyclohexane

Cas Number:

6069-98-3

Molecular formula:

C10H20

IUPAC Name:

rel-(1S,4S)-1-isopropyl-4-methylcyclohexane

Test material form:

liquid

Specific details on test material used for the study:

Appearance: Colourless to pale yellow liquid
Batch: VE00460490
Purity/Composition: See Certificate of Analysis
Test item storage: In refrigerator (2-8°C) protected from light
Stable under storage conditions until: 16 December 2018 (expiry date)
Purity/Composition correction factor: No correction factor required
Test item handling: Use amber glassware or wrap container in aluminum-foil
Chemical name (IUPAC, synonym or trade name: 1-METHYL-4-ISOPROPYL-3-CYCLOHEXENE

Test animals

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

The Wistar Han rat was chosen as the animal model for this study as recognized by international guidelines as a recommended test system. The test method and number of animals were based on the test guidelines.

Species: Rat
Strain: Crl: WI(Han)
Condition: Outbred, SPF-Quality
Source: Charles River France, L’Arbresle, France
Charles River UK, Kent, England
Number of Animals: 5 Females
Females were nulliparous and non-pregnant.
Age at the Initiation of Dosing: Young adult animals (approximately 9-12 weeks old)
were selected.
Weight at the Initiation of Dosing: 189 to 229 g.

On arrival, animals were group housed (up to 5 animals of the same sex together) in polycarbonate cages (Makrolon MIV type; height 18 cm.) and following assignment to the study, animals were individually housed (pilot study) or group housed (main study, up to 5
animals of the same sex and same dosing group together) in polycarbonate cages (Makrolon MIV type; height 18 cm.) containing sterilized sawdust as bedding material (Lignocel S 8-15, JRS - J.Rettenmaier & Söhne GmbH + CO. KG, Rosenberg, Germany) equipped with water bottles. These housing conditions were maintained unless deemed inappropriate by the Study Director and/or Clinical Veterinarian. The room(s) in which the animals were kept were documented in the study records. Animals were separated during designated procedures/activities. Each cage was clearly labeled.

Target temperatures of 18 to 24°C with a relative target humidity of 40 to 70% were maintained. The actual daily mean temperature during the study period was 21 to 22°C with an actual daily mean relative humidity of 43 to 64%. A 12-hour light/12-hour dark cycle was maintained. Ten or greater air changes per hour with 100% fresh air (no air recirculation) were maintained in the animal rooms.

Pelleted rodent diet (SM R/M-Z from SSNIFF® Spezialdiäten GmbH, Soest, Germany) was provided ad libitum throughout the study, except during designated procedures. The feed was analyzed by the supplier for nutritional components and environmental contaminants. Results of the analysis were provided by the supplier and are on file at the Test Facility. It is considered that there were no known contaminants in the feed that would interfere with the objectives of the study.

Municipal tap-water was freely available to each animal via water bottles. Periodic analysis of the water was performed, and results of these analyses are on file at the Test Facility. It is considered that there were no known contaminants in the water that would interfere with the objectives of the study.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

A single dose of test item was administered to the appropriate animals by oral gavage on Day 1, using a syringe with a plastic gavage cannula attached. The Starting dose level was 2000
mg/kg body weight. The dose volume for each animal was based on the body weight measurement prior to dosing.

Dose volume (mL/kg body weight) was calculated as follows:
Dose level (g/kg) / spec.gravity or density (g/mL).
The dosing formulations were stirred continuously during dose administration.
Animals were deprived of food overnight (for a maximum of 20 hours) prior to dosing and until 3-4 hours after administration of the test item. Water was available.

Doses:

2000 mg/kg bw.

No. of animals per sex per dose:

5 females

Control animals:

no

Details on study design:

Initially, Para-Menthene was administered by oral gavage to one female Wistar rat at 2000 mg/kg body weight. As no mortality occurred and no signs of toxicity were observed, the
main study was conducted with a fixed dose of 2000 mg/kg body weight administered to four female rats. The animals were subjected to daily observations. Body weights were
determined on Days 1, 8 and 15. Macroscopic examination was performed after terminal sacrifice.

Statistics:

None.
All results presented in the tables of the report are calculated using values as per the raw data rounding procedure and may not be exactly reproduced from the individual data presented.
The oral LD50 value of the test item was ranked within the following ranges: 0-5, 5-50, 50-300 or 300-2000 mg/kg b.w. or as exceeding 2000 mg/kg b.w. The LD50 cut-off value was established based on OECD guideline 423. No statistical analysis was performed (The method used is not intended to allow the calculation of a precise LD50 value).

Results and discussion

Effect levels

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

not determinable due to absence of adverse toxic effects

Mortality:

At 2000 mg/kg, no mortality occurred and no significant signs of systemic toxicity were observed during the observation period.

Clinical signs:

Lethargy, hunched posture, uncoordinated movements, head tilt, head drop, abnormal gait, piloerection, deep respiration, hypersensitivity to touch, salivation, chromodacryorrhoea (snout) and/or ptosis were noted among the animals on Day 1. Additionally, hunched posture was noted for one animal between Days 2 and 5.

Body weight:

The body weight gain shown by the animals over the study period was considered to be similar to that expected of normal untreated animals of the same age and strain.

Gross pathology:

No abnormalities were found at macroscopic post mortem examination of the animals.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The minimum oral lethal dose of Para-Menthene in rats was established to exceed 2000 mg/kg body weight. The highest dose level of Para-Menthene that did not produce mortality in Wistar rats was established as 2000 mg/kg body weight.
According to the OECD 420 test guideline, the LD50 cut-off value was considered to exceed 2000 mg/kg body weight.

Executive summary:

LD50 > 2000 mg/kg body weight.