2,5-di-tert-butylhydroquinone

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

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 (Acute Toxicity (Oral))

Deviations:

no

GLP compliance:

yes

Test type:

fixed dose procedure

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

2,5-di-tert-butylhydroquinone

EC Number:

201-841-8

EC Name:

2,5-di-tert-butylhydroquinone

Cas Number:

88-58-4

Molecular formula:

C14H22O2

IUPAC Name:

2,5-di-tert-butylhydroquinone

Specific details on test material used for the study:

The test substance is identified as di-tert-butyl hydroquinone. The purity is 99.6%. The physical state/appearance of material is white solid. The expiry date of material is 01 march 2019. The substance can be stored at room temperature in the dark conditions.

Test animals

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

Female Wistar (RccHanTM :WIST) strain rats were supplied by Envigo RMS (UK) Limited, 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 5 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 8 to 12 weeks of age. The body weight variation did not exceed ±20% of the mean body weight at the start of treatment.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

not specified

Details on oral exposure:

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 group to confirm the survival of the previously dosed animals.

Doses:

300 and 50

Details on study design:

A total of five animals were therefore treated at a dose level of 50 mg/kg in the study and 1 for 300 mg/kg.

Results and discussion

Effect levels

Sex:

female

Dose descriptor:

LD50

Effect level:

50 - 300 mg/kg bw

Based on:

test mat.

Mortality:

The animal treated at a dose level of 300 mg/kg was killed for humane reasons, 1 day after dosing, due to the occurrence of clinical signs of toxicity that approached the severity limit set forth in the UK Home Office Project Licence. There were no deaths noted at a dose level of 50 mg/kg

Clinical signs:

other: Signs of systemic toxicity noted in the animal treated at a dose level of 300 mg/kg were ataxia, hunched posture, lethargy, pilo-erection, ptosis, occasional body tremors, tiptoe gait, emaciation, pallor of the extremities, hypothermia and elevated tail.

Gross pathology:

Hemorrhagic non-glandular epithelium of the stomach was noted at necropsy of the animal treated at a dose level of 300 mg/kg. No abnormalities were noted at necropsy of animals treated at a dose level of 50 mg/kg.

Applicant's summary and conclusion

Interpretation of results:

Category 3 based on GHS criteria

Conclusions:

The acute oral median lethal dose (LD50) of the test item in the female Wistar strain rat was estimated to be in the range of 50 - 300 mg/kg body weight (Globally Harmonized Classification System — Category 3).

Executive summary:

The study was performed to assess the acute oral toxicity of the test item in the Wistar strain rat. Following a sighting test at dose levels of 300 mg/kg and 50 mg/kg, a further group of four fasted females was given a single oral dose of test item, as a suspension in arachis oil BP, at a dose level of 50 mg/kg body weight. Clinical signs and body weight development were monitored during the study. All animals were subjected to gross necropsy. The animal treated at a dose level of 300 mg/kg was killed for humane reasons, 1 day after dosing, due to the occurrence of clinical signs of toxicity that approached the severity limit set forth in the UK Home Office Project Licence. There were no deaths noted at a dose level of 50 mg/kg. Signs of systemic toxicity noted in the animal treated at a dose level of 300 mg/kg were ataxia, hunched posture, lethargy, pilo-erection, ptosis, occasional body tremors, tiptoe gait, emaciation, pallor of the extremities, hypothermia and elevated tail. There were no signs of systemic toxicity noted at a dose level of 50 mg/kg.

Animals treated at a dose level of 50 mg/kg showed expected gains in body weight. In necropsy Hemorrhagic non-glandular epithelium of the stomach was noted at necropsy of the animal treated at a dose level of 300 mg/kg. No abnormalities were noted at necropsy of animals treated at a dose level of 50 mg/kg.The acute oral median lethal dose (LD50) of the test item in the female Wistar strain rat was estimated to be in the range of 50 - 300 mg/kg body weight (Globally Harmonized Classification System — Category 3).