Registration Dossier

Administrative data

Key value for chemical safety assessment

Effects on fertility

Effect on fertility: via oral route
Dose descriptor:
NOAEL
21 mg/kg bw/day
Additional information

The test substance used in investigations supporting this endpoint was TBHP (aqueous 70% solution): all results have been expressed in terms of dry TBHP.

In an oral screening study (TNO Study Director, 1993) no toxicological relevant effects on fertility, reproductive performance or development were found at 21 mg TBHP/kg bwt/day, the highest dose tested. The use of higher treatment levels was not feasible given the occurrence of gastric damage in dose range finding studies that accompanied this investigation. Toxicokinetic data indicate rapid conversion of TBHP to tert-butanol in vivo limiting direct exposure of reproductive tissue to TBHP.


Short description of key information:
Toxicokinetic data demonstrate very low or absent systemic bioavailability. This is consistent with results from a key, GLP compliant guideline screening study which found no adverse effects on reproduction following repeated oral exposure.

Effects on developmental toxicity

Description of key information
Toxicokinetic data demonstrate very low or absent systemic bioavailability. This is consistent with results from a key, GLP compliant guideline developmental toxicity study which found no adverse effects on the foetus following repeated oral exposure.  In addition, teratology studies in two species using the primary metabolite of TBHP, tertiary butyl alcohol (TBA), both found no evidence of teratogenicity at maternally toxic doses.
Effect on developmental toxicity: via oral route
Dose descriptor:
NOAEL
35 mg/kg bw/day
Additional information

No adverse effects on development or litter parameters was found following oral exposure of pregnant rats to TBHP at doses up to 35 mg/kg bwt/day (TNO Study Director, 1993). The use of higher treatment levels was not feasible given the occurrence of gastric damage at higher oral doses while toxicokinetic data indicate rapid conversion of TBHP to tert-butanol in vivo limiting direct exposure of the foetus to TBHP.

The test substance used in this investigation was TBHP (aqueous 70% solution): results have been expressed in terms of dry TBHP.

Studies in mice and rats on TBA similarly found no evidence of teratogenicity, even at doses clearly resulting in maternal toxicity, further supporting the conclusion that TBHP is not expected to present a reproductive or developmental toxicity hazard.

Justification for classification or non-classification

Toxicokinetic data demonstrate rapid conversion of TBHP to TBA in vivo limiting the potential for exposure of gonadal tissue. Results from a rat oral reproduction screening study and a rat oral developmental toxicity text demonstrate no adverse effects on fertility, reproductive performance or foetal development. No classification required under EC Regulation 1272/2008 (CLP)