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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

PBT status:
the substance is not PBT / vPvB
Justification:

TBBS (95 -31 -8): Neither the P (vP), the B (vB) nor the T criteria are fulfilled and therefore TBBS is not PBT or vPvB.

TBBS hydrolyses fast with a half-life of 7.76 - 9.53 hours at pH 7 and 25°C. The main hydrolysis products of TBBS are MBT (149 -30 -4) and tert-butylamine (75 -64 -9). Therefore the hydrolysis products have to be taken into account for the assessment, as well.

MBT (149-30-4): MBT is not persistent due to fast hydrolysis but its photolysis products BT and BTon are persistent and the described metabolite MeSBT is also persistent. MBT is neither B (vB) nor T and therefore it can be concluded that MBT is not PBT or vPvB. MBT being released into the waste water and the atmosphere undergo different degradation reactions. The known reaction pathways and relevant metabolites of MBT are already described in the appendix A of the EU-Risk Assessment for CBS from 2008. These described metabolites are MBTS (CAS: 120-78-5), BT (CAS: 95-16-9), BTon (CAS: 934-34-9), MeSBT (CAS: 615-22-5). As the BCF values of all metabolites are smaller than 2000 (EU-RAR, 2008) the B (vB) criteria are not filfilled and therefore the metabolites are neither PBT nor vPvB.

tert-butylamine (75-64-9): The substance does not fulfil the B (vB) criteria and therefore tert-butylamine is neither PBT nor vPvB.

Neither the substance TBBS itself nor the corresponding transformation products have to be classified as PBT or vPvB.

The above stated evaluation is further supported by a published report of the TC NES subgroup of 2008 in which the PBT and vPvB properties of TBBS were assessed.

"Persistence: N-tert-butylbenzothiazole-2-sulphenamide (TBBS) does not meet the P criterion due to a rapid hydrolysis observed in two OECD 111 -tests. Degradation of the identified hydrolysis products was not further reviewed for this report since they are not considered as PBT substances due to their low bioaccumulation potential.

Bioaccumulation: No experimental data on bioaccumulation of TBBS are available. However, the substance is not likely to be subject to relevant bioaccumulation due to its fast hydrolysis. The identified hydrolysis products do not meet the B criterion based on the available logKow –values and/or experimental BCF-values.

Toxicity: Data on ecotoxicity were not reviewed for this report.

Summary: N-tert-butylbenzothiazole-2-sulphenamide (TBBS) does not meet the P criterion due to a fast hydrolysis. Degradation of its identified hydrolysis products was not assessed for this report. TBBS is not likely to be subject to relevant bioaccumulation in the environment due to its fast hydrolysis. The hydrolysis products do not meet the B criterion. Ecotoxicity data were not reviewed for this report. It is concluded that the substance is not considered as a PBT substance." (TC NES subgroup, 2008)