2,2'-(cyclohexylimino)bisethanol

PBT assessment

PBT assessment: overall result

Reference

Name:

2,2'-(Cyclohexylimino)diethanol

Type of composition:

legal entity composition of the substance

State / form:

liquid

Reference substance:

2,2'-(Cyclohexylimino)diethanol

PBT status:

the substance is not PBT / vPvB

Justification:

PERSISTENCE

In an enhanced OECD301B study the registration substance (17 mg/L; 10.8 mg C/L) reached the required level of 60% degradation within 43 days, the substance is therefore ultimately biodegradable using a non-adapted municipal activated sludge. Continuous degradation could be observed starting at day 6 reaching a maximum of 91% degradation on day 60. The only enhancement was the prolongation to 60 days.

Degradation of the registration substance in soil and sediment is likely. No stable metabolites are expected based on degradation pathway modeling. Cyclohexylamine, which is an important metabolite is assessed to be readily biodegradable during CoRAP process of the substance.

Therefore, it can be concluded that the substance is not P and not vP.

BIOACCUMULATION

The registration substance has a low potential for uptake into the organism independent if the driving mechanism is hydrophobicity (log Kow=1.57, calculated BCF < 12 L/kg) or includes an ionic mechanism (logkplip-w < 2.35, conservatively derived from C8-alkyl-dimethyl amine).

It is very unlikely that the ionic registration substance would pass biological membranes.

For similar substances (C9-alkyl-dimethyl amine and C10-alkyl-dimethyl amine), within the ECO37 project fast biotransformation has been shown with measured in-vitro clearance rates (CLS9 of around 300 ml/h/g liver) and an in-vivo bioaccumulation experiment indicated low potential to bioaccumulate (Uptake rate (K1) = 2.2 L/kg.h; Elimination rate (K2) = 0.057 1/h; BCFkinetic = 40 L/kg). All similar substances have longer alkyl-chains than the registration substance, and in all cases the values increase with increasing alkyl-chain-length. Therefore, all values can be seen as worst-case conservative approach. (Further details can be found in IUCLID Chapter 5.3)

 

In conclusion the substance has a low bioaccumulation potential and is not B and not vB.

TOXICITY

The available acute and chronic aquatic ecotoxicty data of registration substance are all > 1mg/L. In addition the registration substance is not classified as carcinogenic, mutagenic or reprotoxic as given in the Criteria for the PBT / vPvB Assessment. But the registration substance is classified under DSD 67/548/EEC as Xn, R48 and under 1272/2008/EC as having a specific target organ toxicity after repeated exposure (STOT RE category 2). This means the 'T' criteria for the PBT / vPvB Assessment is fulfilled.

OVERALL

The registration substance fulfilles the Crititera 'T' but not the 'P' or 'B' criteria relevant for the PBT Assessment under REACH. The overall result is therefore: The registration substance is not PBT/vPvB according the criteria for the PBT Assessment under REACH.