Registration Dossier

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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Stability of PTAP in the environment:

In accordance with Annex X of the Regulation (EC) No 1907/2006 REACH concerning the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH), phototransformation in air, as well as in water and soil, are not mandatory requirements. However, modeled data on phototransformation in air is presented for informational purposes.

The authors found that the calculated vapour phase half-life p-tert-amylphenol was 3 hours.

No data are available on hydrolysis of p-tert-amylphenol. The substance is an alkyl-substituted phenol derivative and has no functional groups that can be hydrolyzed, i.e. ester, amide or any substituents on the alkyl-groups or the aromatic ring that could be substituted by OH- ions under the condition of the guideline test on hydrolysis as function of pH (OECD 111, EU method C7). Therefore from the structure of the substance it can be deduced that it does not undergo abiotic degradation through hydrolysis and the study is scientifically unjustified.

Biodegradation of PTAP:

Reliable measured biodegradation studies for p-tert-amylphenol and the analogue, p-tert-butylphenol, are available and included in the dossier. A reliable study by Haener (1999) showed that p-tert-amylphenol degraded 73% at the end of the 28 day test, although did not pass the 10-day window. A reliable study by Matthews and Schaefer (2013) showed that p-tert.-butylphenol degraded 59% and 64%, in two different test concentrations, at 28 days, although did not pass the 10-day window.As per REACH Guidance Ch R.7.b, ready biodegradability tests can be used to prove inherent biodegradability when the pass level criterion is almost fulfilled (i.e., slightly below 60% degradation). Since degradation of 73% (Haener 1999) and 59% and 64% (Matthews and Schaefer 2013) occurred during the study, the test substance can be deemed inherently biodegradable. The key and supporting study results indicate that the test substance biodegrades rapidly once microbes have had a chance to acclimate. All effluents related to the use of p-tert-amylphenol will be through industrial WWTP as the substance is used as an intermediate. Any release to wastewater treatment plant or soil from residual p-tert-amylphenol in resin is negligible.

Bioaccumulation of PTAP:

Measured bioconcentration information for aquatic or terrestrial organisms is not available for p-tert-amylphenol, although modeled data are presented below.  

Reliable modeled BCF value for p-tert-amylphenol, using the measured log Kowof 3.6 was estimated to be 229 L/kg wt for fish. Other modeled data and supporting data for the structural analogue indicate that there may be low potential for bioaccumulation of p-tert-amylphenol. Although the The Environmental Risk Assessment Report:4-tert-pentylphenol (CAS no. 80-46-6) (Environment Agency, 2008) (RAR) concludes that the study values suggest a modest potential for p-tert-amylphenol, to bioconcentrate, the report concludes that the modeled BCF may be overestimated. In all cases, though, BCF values are well below the REACH bioaccumulation criterion (B) of 2000.

Reliable modeled BCF value for p-tert-amylphenol, using the measured log Kowof 3.6 was estimated to be 48.6 L/kg wt for earthworm. Other supporting data indicate that there may be very low potential for bioaccumulationof p-tert-amylphenol in terrestrial organisms.

In accordance with REACH annex VIII, a substance fulfills the bioaccumulation criterion (B) when the bioconcentration factor in aquatic species is higher than 2 000. Therefore, p-tert-amylphenol is not considered bioaccumulative in aquatic or terrestrial organisms.

Transport and distribution of PTAP:  

No reliable measured absorption (Koc) values are available for p-tert-amylphenol. However, modeled Koc values have been predicted using quantitative structure– activity relationships (QSARs), based on Kow. The European Union System for the Evaluation of Substances (EUSES) model was used to estimate bioconcentration for p-tert-amylphenol. Using the measured log Kow of 3.6, a Koc of 1470 L/kg was estimated.

No data are available regarding Henry’s Law and Distribution for p-tert-amylphenol. In accordance with the REACH Regulations determination of Henry’s Law and distribution are not standard information requirements.