2,6-Octadienal, 3,7-dimethyl-, acid-isomerized

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1.12.2016-19.12.2016

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 402 (Acute Dermal Toxicity)

Version / remarks:

Adopted: 24th February 1987

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2,6-Octadienal, 3,7-dimethyl-, acid-isomerized

EC Number:

291-768-8

EC Name:

2,6-Octadienal, 3,7-dimethyl-, acid-isomerized

Cas Number:

90480-35-6

IUPAC Name:

1-methyl-4-(propan-2-yl)benzene; ethanol

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 8 - 9 weeks
- Weight at study initiation: 287.1−308.3g for males and 211.1−241.9g for females
- Housing: one animal per stainless wire mesh cage
- Diet: ad libitum; pelleted rodent chow (Teklad Certified Irradiated Global 18% Protein Rodent Diet 2918C, Envigo RMS, Inc., U.S.A.)
- Water: ad libitum; public tap water in Cheongju-si was filtered and irradiated by ultraviolet light
- Acclimation period: 4 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21.1−24.5
- Humidity (%): 45.7−63.9
- Air changes (per hr): 10−15
- Photoperiod (hrs dark / hrs light): 12

Administration / exposure

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

The test item was applied to an area of approximately 5 cm×6 cm for males and females. After the application of the test substance to a lint tape, the application site was covered with the lint tape and plastic film. Each animal’s back was over-wrapped with Soft Cloth Tape with Liner (5 cm width, 3M Co., Ltd., Republic of Korea) and surgical tape.
Dose volume: 2.24 mL/kg body weight.

Duration of exposure:

24 hours

Doses:

2000 mg/kg

No. of animals per sex per dose:

5 males/5 females

Control animals:

yes, concurrent no treatment

Details on study design:

RANGE FINDING STUDY
- goal: Justification for dose level
- animals: 1 male and 1 female
- dose: 2000 mg/kg
- dose volume: 2.24 mL/kg

MAIN STUDY

OBSERVATIONS
Clinical signs
All animals were observed for mortality, general condition and clinical signs (type, severity, time of onset and recovery) at 30 minutes after dosing and at 1, 2, 4 and 6 hours after dosing on Day 0 and once daily thereafter for 14 days (Day 1−Day 14).

Body weights
The body weights were recorded prior to dosing on Day 0 and on Days 3, 7 and on the day of necropsy, Day 14.

PATHOLOGY
Necropsy
On Day 14, all animals were anesthetized with CO2 and exsanguinated from the abdominal aorta. Complete gross postmortem examinations were performed on all animals in the study.

Histopathology
Since no gross findings were observed at necropsy, histopathological examinations were not performed.

Statistics:

Statistical analysis was performed using SAS Program (version 9.3, SAS Institute Inc., U.S.A.). Body weights were analyzed utilizing Folded-F test for homogeneity of variance (significance level: 0.05). Student t-test was employed on homogeneous data (significance levels: 0.05 and 0.01, two-tailed).

Results and discussion

Preliminary study:

In a preliminary study, one male and one female rat were dermally dosed at a dose of 2000 mg/2.24 mL/kg. No deaths occurred. Therefore, the dose level was selected at 2000 mg/kg for the main study.

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 of animals in the 2,000 mg/kg groups.

Clinical signs:

other: No abnormalities of clinical signs were observed in any animal in the control groups and 2000 mg/kg groups throughout the study.

Gross pathology:

No grossly visible findings were observed in any animal in the control groups and 2000 mg/kg groups.

Other findings:

No other findings to report.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Based on the result of this study, the LD50 value of the test substance was considered to be greater than 2000 mg/kg in male and female rats under the conditions of this study.

According to the EU Regulation No. 1272/2008, the test substance does not need to be classified and has no obligatory labelling requirement.

Executive summary:

The purpose of this study was to assess the potential toxicity and the approximate LD50 value of the test substance following a single dermal application to Sprague-Dawley rats. The study was carried out in accordance with OECD Guideline No. 402, "Acute Dermal Toxicity" and under GLP regulations.

Test groups consisted of one dose group at a dose of 2000 mg/kg and a control group, and each group consisted of 5 males and 5 females. All animals were monitored for clinical signs and bodyweight changes after dosing during the 14-day observation period. They were subjected to gross necropsy at the end of the observation period.

There were no deaths of animals in the 2000 mg/kg groups. No test substance-related effects were observed in clinical signs, bodyweight data or necropsy findings in the 2000 mg/kg groups.

Based on the result of this study, the LD50 is > 2000 mg/kg bw for the test substance in male and female rats and under the conditions of this study.

Hence, the substance should not be classified as acute toxic according to the criteria described in EU Regulation No. 1272/2008 on the Classification, Labelling and Packaging of Substances and Mixtures (CLP).