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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Classification & Labelling & PBT assessment

PBT assessment

Currently viewing:

Administrative data

PBT assessment: overall result

3,5,5 trimethylhexyl 3,5,5 trimethylhexanoate
Type of composition:
boundary composition of the substance
State / form:
Reference substance:
3,5,5 trimethylhexyl 3,5,5 trimethylhexanoate
PBT status:
the substance is not PBT / vPvB

The PBT Assessment for 3,5,5-trimethylhexyl 3,5,5-trimethylhexanoate (CAS 59219-71-5) is based on the criteria set out in the “Guidance on information requirements and chemical safety assessment, Chapter R.11: PBT Assessment” (ECHA, 2014).


Based on read across to branched-nonyl 3,5,5 trimethylhexanoate (EC 701-133-3), the substance 3,5,5-trimethylhexyl 3,5,5-trimethylhexanoate (CAS 59219-71-5) is readily biodegradable (OECD 301B, 91% CO2 evolution after 28 d). Thus, the test substance does not meet the screening criterion for persistency and it is not considered to be P or vP.


The bioaccumulation factor (BCF) of 3,5,5-trimethylhexyl 3,5,5-trimethylhexanoate (CAS 59219-71-5) was estimated using a reliable QSAR model (BCFBAF v3.01; Gerloff-Elias, 2015). The substance fell in the applicability domain of the model indicating that the results are reliable and can be used to assess the bioaccumulation potential of 3,5,5-trimethylhexyl 3,5,5-trimethylhexanoate. The BCF/BAF was calculated to be 152.9 / 703.9 L/kg (upper trophic) using the model of Arnot-Gobas which includes biotransformation. In conclusion, 3,5,5-trimethylhexyl 3,5,5-trimethylhexanoate has a low potential for bioaccumulation and the highest calculated BAF of 703.9 L/kg is clearly below the trigger value of 2000 L/kg to be classified as bioaccumulative (B-criterion) in the PBT assessment. Thus, taking all information into account, the test substance is not considered to be B or vB.


Long-term toxicity testing with the read across substance branched-nonyl 3,5,5 trimethylhexanoate (EC 701-133-3) resulted in a NOELR (21 d) of ≥ 100 mg/L (OECD 211; nominal) for Daphnia magna. All available short-term toxicity data did not result in any toxicity up to the water solubility limit. Moreover, 3,5,5-trimethylhexyl 3,5,5-trimethylhexanoate (CAS 59219-71-5) is not classified according to Directive 67/548/EEC and Regulation (EC) No. 1272/2008. Thus, the criteria set out in Annex XIII of Regulation (EC) No. 1907/2006 are not met and the test substance is not considered to meet the T criterion.


In conclusion the substance is not considered to meet the criteria to be classified as PBT or vPvB based on the available data.