Reaction mass of (2R*,4R*,4aR*,9bS*)-2,4-dimethyl-4,4a,5,9b-tetrahydroindeno[1,2-d][1,3]dioxine and (2R*,4R*,4aS*,9bR*)-2,4-dimethyl-4,4a,5,9b-tetrahydroindeno[1,2-d][1,3]dioxine

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

07 Mar - 29 Mar 2001

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP-Guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2001

Report date:

2001

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

adopted 22 March 1996

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.1 tris (Acute Oral Toxicity - Acute Toxic Class Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

The Department of Health of the Government of the United Kingdom

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

2,4-dimethyl-2H,4H,4aH,5H,9bH-indeno[1,2-d][1,3]dioxine

EC Number:

944-528-8

Molecular formula:

C13H16O2

IUPAC Name:

2,4-dimethyl-2H,4H,4aH,5H,9bH-indeno[1,2-d][1,3]dioxine

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 weeks
- Weight at study initiation: males: 227 - 249 g; females: 201 - 230 g
- Fasting period before study: overnight
- Housing: animals were housed in groups of three by sex in solid-floor polypropylene cages with woodflakes
- Diet: Rat and Mouse Expanded Diet No. 1 (Special Diet Services Limited, Witham, UK), ad libitum
- Water: mains drinking water, ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 - 25
- Humidity (%): 30 - 70
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12 / 12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

arachis oil

Remarks:

Only for the 200 mg/kg bw dose level, the test material was prepared as solution in arachis oil. For the 2000 mg/kg dose level, the test material was used ad supplied.

Details on oral exposure:

VEHICLE
- Justification for choice of vehicle: test material did not dissolve or suspend in distilled water

MAXIMUM DOSE VOLUME APPLIED: 1.83 mL/kg bw (2000 mg/kg bw); 10 mL/kg bw (200 mg/kg bw)

Doses:

2000 mg/kg bw (step 1)
200 mg/kg bw (step 2)

No. of animals per sex per dose:

3 females at 2000 mg/kg bw
3 males and females at 200 mg/kg bw

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Animals were observed 0.5, 1, 2 and 4 hours after dosing and subsequently once daily for 14 days. Individual bodyweights were recorded prior to dosing and 7 and 14 days after treatment or at death.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, gross pathology

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 300 - 500 mg/kg bw

Based on:

test mat.

Remarks on result:

other: according to Appendix 3c in OECD Guideline 423 (adopted Mar 1996)

Mortality:

Two animals treated with 2000 mg/kg bw were found dead one or three days after dosing. One animal treated with 2000 mg/kg bw was killed in extremis one day after dosing. No mortalities were observed at a dose level of 200 mg/kg bw until the end of the study.

Clinical signs:

other: Signs of systemic toxicity noted at a dose level of 2000 mg/kg bw were hunched posture, lethargy, decreased respiratory rate, gasping, laboured and noisy respiration, ataxia, ptosis, dehydration, increased lachrymation, hypothermia, body tremors, prostrat

Gross pathology:

Abnormalities noted at necropsy of animals that died or were killed in extremis during the study were haemorrhagic lungs, dark liver or patchy pallor of the liver, dark kidneys, haemorrhage and sloughing of the gastric mucosa, sloughing of the non-glandular region of the stomach and haemorrhagic small intestine. No abnormalities were noted at necropsy of animals that were killed at the end of the study.

Any other information on results incl. tables

Table 1. Results of the acute toxicity study.

Dose level (mg/kg bw)	Mortalities
	Male	Female
2000	-	3/3
200	0/3	0/3

Applicant's summary and conclusion

Interpretation of results:

harmful

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

In this acute oral toxicity study in rats a LD50 value of > 300 - 500 mg/kg bw was found.