1,3,4,6,7,8a-hexahydro-1,1,5,5-tetramethyl-2H-2,4a-methanonaphthalen-8(5H)-one

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was conducted between 23 April 2014 and 28 May 2014.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2014

Report date:

2014

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.1 bis (Acute Oral Toxicity - Fixed Dose Procedure)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

fixed dose procedure

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

1,3,4,6,7,8a-hexahydro-1,1,5,5-tetramethyl-2H-2,4a-methanonaphthalen-8(5H)-one

EC Number:

245-890-3

EC Name:

1,3,4,6,7,8a-hexahydro-1,1,5,5-tetramethyl-2H-2,4a-methanonaphthalen-8(5H)-one

Cas Number:

23787-90-8

Molecular formula:

C15H24O

IUPAC Name:

1,1,5,5-tetramethylhexahydro-2H-2,4a-methanonaphthalen-8(5H)-one

Test material form:

other: Liquid

Details on test material:

Identification: Isolongifolanone
Batch: SC00010626
Purity: 69.9%
Physical state / Appearance: Extremely pale yellow liquid
Expiry Date: 17 February 2016
Storage Conditions: Room temperature in the dark

Test animals

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

Animals and Animal Husbandry
Female Wistar (RccHan™:WIST) strain rats were supplied by Harlan Laboratories UK Ltd., Oxon, UK. On receipt the animals were randomly allocated to cages. The females were nulliparous and non pregnant. After an acclimatization period of at least five days the animals were selected at random and given a number unique within the study by indelible ink marking on the tail and a number written on a cage card. At the start of the study the animals were eight to twelve weeks of age. The body weight variation did not exceed ±20% of the body weight of the initially dosed animal.

The animals were housed in groups of up to four in suspended solid floor polypropylene cages furnished with woodflakes. With the exception of an overnight fast immediately before dosing and for approximately three to four hours after dosing, free access to mains drinking water and food (2014C Teklad Global Rodent diet supplied by Harlan Laboratories UK Ltd., Oxon, UK) was allowed throughout the study. The diet, drinking water and bedding were routinely analyzed and were considered not to contain any contaminants that would reasonably be expected to affect the purpose or integrity of the study.

The temperature and relative humidity were set to achieve limits of 19 to 25 °C and 30 to 70% respectively. The rate of air exchange was at least fifteen changes per hour and the lighting was controlled by a time switch to give twelve hours continuous light (06:00 to 18:00) and twelve hours darkness.

The animals were provided with environmental enrichment items which were considered not to contain any contaminant of a level that might have affected the purpose or integrity of the study.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

arachis oil

Details on oral exposure:

Test Item Formulation and Experimental Preparation
For the purpose of the 2000 mg/kg dose level, the test item was used as supplied. The specific gravity was determined and used to calculate the appropriate dose volume for the required dose level. For the purpose of the 300 mg/kg dose level, the test item was freshly prepared, as required, as a solution in arachis oil BP. Arachis oil BP was used because the test item did not dissolve/suspend in distilled water.

The test item was formulated within two hours of being applied to the test system. It is assumed that the formulation was stable for this duration.

No analysis was conducted to determine the homogeneity, concentration or stability of the test item formulation. This is an exception with regard to GLP and has been reflected in the GLP compliance statement.

Doses:

300 mg/kg (concentration 30 mg/L) at a dose volume of 10 mL/kg.
2000 mg/kg (specific gravity: 0.999) at a dose volume of 2.01 mL/kg.

No. of animals per sex per dose:

1 female at 300 mg/kg
5 female at 2000 mg/kg

Control animals:

no

Details on study design:

In the absence of data regarding the toxicity of the test item, 300 mg/kg was chosen as the starting dose.

A single animal was treated as follows: 300 mg/kg (concentration 30 mg/L) at a dose volume of 10 mL/kg.

In the absence of toxicity at a dose level of 300 mg/kg, an additional animal was treated as follows: 2000 mg/kg (specific gravity: 0.999) at a dose volume of 2.01 mL/kg.
In the absence of mortality at a dose level of 2000 mg/kg, an additional group of 4 animals was treated as follows: 2000 mg/kg (specific gravity: 0.999) at a dose volume of 2.01 mL/kg.

A total of five animals were therefore treated at a dose level of 2000 mg/kg in the study.

All animals were dosed once only by gavage, using a metal cannula attached to a graduated syringe. The volume administered to each animal was calculated according to the fasted body weight at the time of dosing. Treatment of animals was sequential. Sufficient time was allowed between each dose level to confirm the survival of the previously dosed animals.

Clinical observations were made 0.5, 1, 2, and 4 hours after dosing and then daily for fourteen days. Morbidity and mortality checks were made twice daily.

Individual body weights were recorded on Day 0 (the day of dosing) and on Days 7 and 14.

At the end of the observation period the animals were killed by either exposure to a rising concentration of carbon dioxide followed by cervical dislocation or cervical dislocation alone. 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.

Results and discussion

Effect levels

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

At dose level 300 mg/kg there was no mortality.
At dose level 2000 mg/kg there were no deaths.

Clinical signs:

other: At dose level 300 mg/kg there were no signs of systemic toxicity were noted during the observation period. At dose level 2000 mg/kg ataxia and increased respiratory rate were noted during the day of dosing in the initial treated animal. Hunched posture w

Gross pathology:

At dose level 300 mg/kg there were no abnormalities were noted at necropsy.
At dose level 2000 mg/kg there were no abnormalities were noted at necropsy.

Any other information on results incl. tables

Individual Clinical Observations and Mortality Data 300mg/kg

Dose Level mg/kg	Animal Number and Sex	Effects Noted After Dosing (Hours)				Effects Noted During Period After Dosing (Days)
		½	1	2	4	1	2	3	4	5	6	7	8	9	10	11	12	13	14
300	1-0 Female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0

0=   No signs of systemic toxicity

Individual Body Weights and Body Weight Changes 300mg/kg

Dose Level mg/kg	Animal Number and Sex	Body Weight (g) at Day			Body Weight Gain (g) During Week
		0	7	14	1	2
300	1-0 Female	166	187	199	21	12

Necropsy Findings 300 mg/kg

Dose Level mg/kg	Animal Number and Sex	Time of Death	Macroscopic Observations
300	1-0 Female	Killed Day 14	No abnormalities detected

Individual Clinical Observations and Mortality Data 2000mg/kg

Dose Level mg/kg	Animal Number and Sex	Effects Noted After Dosing (Hours)				Effects Noted During Period After Dosing (Days)
		½	1	2	4	1	2	3	4	5	6	7	8	9	10	11	12	13	14
2000	2-0 Female	ARi	Ri	Ri	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	3-0 Female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	3-1 Female	0	H	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	3-2 Female	0	H	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	3-3 Female	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0

0=   No signs of systemic toxicity

A =  Ataxia

H =  Hunched posture

Ri = Increased respiratory rate

Individual Body Weights and Body Weight Changes 2000mg/kg

Dose Level mg/kg	Animal Number and Sex	Body Weight (g) at Day			Body Weight Gain (g) During Week
		0	7	14	1	2
2000	2-0 Female	151	180	199	29	19
	3-0 Female	179	200	216	21	16
	3-1 Female	184	212	226	28	14
	3-2 Female	172	190	201	18	11
	3-3 Female	180	207	219	27	12

Individual Necropsy Findings 2000mg/kg

Dose Level mg/kg	Animal Number and Sex	Time of Death	Macroscopic Observations
2000	2-0 Female	Killed Day 14	No abnormalities detected
	3-0 Female	Killed Day 14	No abnormalities detected
	3-1 Female	Killed Day 14	No abnormalities detected
	3-2 Female	Killed Day 14	No abnormalities detected
	3-3 Female	Killed Day 14	No abnormalities detected

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The acute oral median lethal dose (LD50) of the test item in the female Wistar strain rat was estimated to be greater than 2000 mg/kg body weight.

Executive summary:

Introduction

The study was performed to assess the acute oral toxicity of the test item in the Wistar strain rat.

 

Methods

Following a sighting test at dose levels of300 mg/kg and2000 mg/kg, a further group of four fasted females was given a single oral dose of test item at a dose level of2000 mg/kg body weight. Clinical signs and body weight development were monitored during the study. All animals were subjected to gross necropsy.

 

Results

Mortality. There were no deaths.

 

Clinical Observations. Signs of systemic toxicity noted at a dose level of 2000 mg/kg were hunched posture, ataxia and increased respiratory rate. There were no signs of systemic toxicity noted in two animals treated at a dose level of 2000 mg/kg and the animal treated at a dose level of 300 mg/kg.

 

Body Weight. All animals showed expected gains in body weight.

 

Necropsy. No abnormalities were noted at necropsy.

 

Conclusion

The acute oral median lethal dose (LD₅₀) of the test item in the female Wistar strain rat was estimated to be greater than2000 mg/kg body weight (Globally Harmonized Classification System-Category 5).