Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Link to relevant study record(s)

Description of key information

Based on physico-chemical properties (low molecular weight, moderate log Ko/w, high water solubility), TAHP is likely to penetrate human body by oral, dermal and inhalation exposure.

Tert-amyl hydroperoxide (TAHP) is a colourless liquid with a molecular weight of 104.1 g/mol. The substance is soluble in water (63.25 g/L à 25 °C). The logKow of TAHP is estimated to be around 2.9. TAHP has a relatively high vapor pressure: 43.20 hPa at 25 °C. The calculated log BCF is 1.580: there is no bioaccumulation potential.

TAHP does not rapidly degrade hydrolytically at pH 4, 7 and 9 for 5 days at 50°C (half live > 1 year). At pH 1.2 and 37°C for 2 and 4 hours, no hydrolysis of the 0.01 M TAHP solution (1.04 g/L) was observed.

Therefore no tert-amyl alcohol is expected to be formed in stomach neither in rats nor in humans, unless an enzymatic transformation occurs.

Oral absorption is favored for molecular weights below 500 g/mol. Based on the moderate logKow and the high water solubility, TAHP can be regarded as a hydrophilic substance. Based on these physico-chemical properties it can be assumed that significant absorption across the gastrointestinal tract epithelium may occur when administered in repeated dosages. This is confirmed by acute oral toxicity data, in which systemic effects were observed.

Based on the high vapor pressure, inhalation is the most reliable route of exposure. In addition the small size of the molecule, its water solubility and its mild logKow are in favor of inhalation uptake. Together, this indicates relatively high systemic availability after inhalation.

Based on physical – chemical properties of TAHP, the substance is likely to penetrate skin. In addition, application of TAHP to skin of rabbits is responsible of severe skin damages, which could enhance the skin absorption. Applied to the skin of guinea pigs, sensitizing effects were observed, indicating that at least small amounts of the substance become available in the body. In addition, systemic effects were observed after a single dermal administration, showing that the substance (or its metabolite) is systemically available.

In conclusion, 100 % of tert-amyl hydroperoxide is considered to be absorbed by inhalation, by oral route and by dermal route.

There is no information on metabolism and toxicokinetic for TAHP. Nevertheless, it is expected that TAHP hydrolyses quickly in the blood in tert-amyl alcohol by an enzymatic way.

Key value for chemical safety assessment

Bioaccumulation potential:
no bioaccumulation potential
Absorption rate - oral (%):
Absorption rate - dermal (%):
Absorption rate - inhalation (%):

Additional information