(2α,4aα,8α)-hexahydro-1,1,5,5-tetramethyl-2H-2,4a-methanonaphthalen-8(5H)-one

Endpoint summary

Description of key information

The median lethal dose was LD50 ≥ 2000 mg/kg bw. The test substance does not need to be classified for acute oral toxicity.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

18.10.2016 - 13.01.2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 8-9 weeks
- Weight at study initiation: 178.8−227.9 g
- Housing: Stainless wire mesh cage, 260W×350D×210H (mm), 1 animal / cage
- Diet: ad libitum, pelleted rodent chow (Teklad Certified Irradiated Global 18% Protein Rodent Diet 2918C)
- Water: ad libitum, public tap water in Cheongju-si was filtered and irradiated by ultraviolet light
- Acclimation period: 7 days (quarantined for 4 days and acclimated for 3 days)
- Fasting period before study: 16 hours

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20.7−22.9
- Humidity (%): 48.4−58.8
- Air changes (per hr): 10−15 clean, fresh, filtered air
- Photoperiod (hrs dark / hrs light): 12 hour light/dark cycle (7 AM−7 PM via automated timer), 150−300 Lux

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

- The required amount of the test substance was weighed by an electronic balance and the vehicle, corn oil, was added and mixed gradually to yield the desired concentrations (60 and 400 mg/mL).
- All preparations were conducted just prior to use.
- Stability and concentration analyses of dosing formulations were not performed.
- Individual doses were calculated based on the animals’ body weight recorded prior to dosing at a dose volume of 5 mL/kg body weight. Animals were dosed via gastric intubation with a 1- or 3-mL syringe fitted with an intubation tube.

Doses:

300 and 2000

No. of animals per sex per dose:

6

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: day 0, 1, 3, 7 and 14
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight and histopathology

Statistics:

Statistical analysis was not performed. Mean scores and values were determined.

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No animals died during the course of the study.

Clinical signs:

Mucous stool was observed in 3 animals at 300 mg/kg and 2 animals at 2,000 mg/kg on Day 1, however, this disappeared on Day 2. It was considered to be a test substance-related temporary change.

Body weight:

Normal body weight gain was observed in all animals throughout the study.
A tendency for suppression of body weight gain was observed in 1 animal at 2,000 mg/kg on Day 1. However, the body weight gain normalized in this animal on Day 3. This change was considered to be a test substance-related effect.

Gross pathology:

No gross visible findings were observed in any animal at 300 and 2,000 mg/kg.

Interpretation of results:

GHS criteria not met

Conclusions:

The median lethal dose was LD50 ≥ 2,000 mg/kg b.w. Based on the result the test substance does not need to be classified.

Executive summary:

In this study the potential toxicity of the test item was assessed following a single oral dose administration to female Sprague-Dawley rats. The test was carried out according to OECD 423 and GLP.

Four dose groups of three females were used as follows: Groups 1 and 2 (Steps 1 and 2): 300 mg/kg of the test substance and groups 3 and 4 (Steps 3 and 4): 2,000 mg/kg of the test substance. In steps 1 a dose of 300 mg/kg was administered. No mortality was observed, whereafter a second dose of 300 mg/kg was administered (Step 2).

In steps 3 and 4 a dose of 2,000 mg/kg was administered as no mortality was observed in the first 2 steps. In step 3 no animals died and therefore a fourth dose of 2,000 mg/kg was administered (Step 4).

All animals were monitored for clinical signs and body weight changes during the 14-day observation period after administration and subjected to gross necropsy at the end of the observation period.

There were no deaths at any dose and no gross pathologic findings were observed in any animal at 300 and 2,000 mg/kg.

Mucous stool was observed in 3 animals at 300 mg/kg and 2 animals at 2,000 mg/kg on Day 1, however, this disappeared on Day 2.

Normal body weight gain was observed in all animals throughout the study. A tendency for suppression of body weight gain was observed in 1 animal at 2,000 mg/kg on Day 1. However, the body weight gain normalized in this animal on Day 3. This change was considered to be a test substance-related effect.

The median lethal dose was LD50 ≥ 2,000 mg/kg b.w. Based on the result of the current acute oral toxicity study, the test substance does not need to be classified according to CLP regulation.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Additional information

For this endpoint, 1 study is available for acute oral toxicity. In this study the potential toxicity of the test item was assessed following a single oral dose administration to female Sprague-Dawley rats. The test was according to OECD 423 and GLP. The testing was done in 4 steps and the dose given in the first 2 steps was 300 mg/kg, while the dose in the second group was 2000 mg/kg.

All animals were monitored for clinical signs and body weight changes during the 14-day observation period and subjected to gross necropsy at the end of the observation period.

There were no deaths at any dose and no gross pathologic findings were observed in any animal.

Mucous stool was observed in 3 animals at 300 mg/kg and 2 animals at 2000 mg/kg on Day 1, however, this disappeared on Day 2.

Normal body weight gain was observed in all animals throughout the study.

The median lethal dose was LD50 > 2000 mg/kg b.w. Based on the result of the current acute oral toxicity study, the test substance does not need to be classified according to CLP regulation.

Justification for classification or non-classification

According to the EU Regulation No. 1272/2008 on the Classification, Labelling and Packaging of Substances and Mixtures (CLP) the substance is not considered to be classified as acute toxic because the LD50 is > 2000 mg/kg bw (Table 3.1.1).