Registration Dossier

Administrative data

Description of key information

Acute toxicity of this substance is the range of oral LD50 value 130-800 mg/kg in rats and mice. Toxic signs were found at 800 mg/kg in males and 130 mg/kg or more in female rats. These were hypoactivity, a prone or lateral position and soiled fur. Bradypnea and Cheyne-Strokes' respiration in moribund animals of both sexes and hypothermia, clonic convulsion, ataxic gait and vocalisation in females were observed. 
Studies for acute inhalative and acute dermal toxicity are not available

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion
Dose descriptor:
LD50
130 mg/kg bw

Additional information

The acute oral LD50 value is in the range of 130 -800 mg/kg bw (M: 320 -800 mg/kg, F:130 -320 mg/kg)

number of dead animals/number of dosed animals:

M: 130 mg/kg: 0/5, 320 mg/kg: 0/5; 800 mg/kg; 4/5, 2000 mg/kg: 3/5

F: 130 mg/kg: 0/5, 320 mg/kg: 3/5; 800 mg/kg; 4/5, 2000 mg/kg: 4/5

Studies for acute inhalative and acute dermal toxicity are not available and not necessary, because 6-tert-butyl-m-cresol shall be registrated according REACH Article 18 (transported isolated intermediate).

Additional 6-tert-butyl-m-cresol is classifed as C, R34 (corrosive, causes burns). Studies for acute inhalation and acute dermal toxicity are therefore not justified scientifcally and are precluded on grounds of animal welfare.

Justification for classification or non-classification

from the results of the acute toxicity study the dead rate shows the same tendency in male and female rats - with the exception of the dose group of 320 mg/kg. In this dose group none of the male animals died but 3 of 5 female rats died. In higher dose groups (800 mg/kg) the same number of male and female rats died. In the dose group of 2000 mg/kg 3 of 5 male rats died and 4 of 5 female rats died.

Because the death rate in male and female rats is not very different in each gender with the exception of the dose group of 320 mg/kg where considerable more female rats died - there in no clear evidence for a clear higher sensitivity of the female rats.

In conclusion the LD50 value for both genders seems between 130 and 800 mg/kg bw and not at the lower end of this range.

A classification as Xn (harmful), R22 (harmful if swallowned) is justified.