Choline hydroxide

PBT assessment

PBT assessment: overall result

Reference

Reference 1

Name:

Choline hydroxide

Type of composition:

boundary composition of the substance

State / form:

other: aqueous solution

Reference substance:

Choline hydroxide

Reference 2

Name:

Choline hydroxide

Type of composition:

legal entity composition of the substance

State / form:

other: aqueous solution

Reference substance:

Choline hydroxide

PBT status:

the substance is not PBT / vPvB

Justification:

Criteria for assessing PBT properties are defined in Annex XIII, REACH Regulation (EC) No. 1907/2006. Further details are laid down in ECHA Guidance on Information Requirements and Chemical Safety Assessment; Chapter R.11: PBT Assessment (June 2017). The assessment of PBT / vPvB properties is based upon a separate assessment for each parameter (i.e. P or vP, B or vB and T). Substances are only assigned as PBT or vPvB when they fulfill the criteria for all three properties (persistency, bioaccumulation and toxicity in case of PBT substance) or both criteria (i.e. very persistent and very bioaccumulative) in case of vPvB, respectively.

Based on a valid experimental result, the close analogue Choline chloride is considered as "readily biodegradable" (BASF AG, 1988) and therefore not persistent in the environment. This ist also valid for Choline base. Also the B criterion (Bioaccumulative substance) is not fulfilled based on the experimentally determined logPow of -2.25 for Choline base (Intertek, 2013) and the QSAR predicted Bioconcentration Factor (BCF) of 3.16 L/kg for Choline base (Chemservice S.A., 2013), which is far below the trigger value of 100 L/kg. Due to the lack of toxicity observed in ecotoxicity studies, also the first T screening criterion is not fulfilled. Furthermore, no classification exists as carcinogenic, mutagenic or toxic for reproduction according to Regulation (EC) No. 1272/2008. The test substance is neither classified as "T, R48" or as "Xn, R48" based on the criteria laid down in Directive 67/548/EEC nor as STOT RE category 1 or 2.

As conclusion, Choline hydroxide fulfills none of the required parameters and is neither a PBT nor a vPvB substance.

Likely routes of exposure:

Choline hydroxide as an aqueous solution is a colourless to light yellow and nearly odourless liquid.

Workers may be exposed via the dermal route due to substance handling during manufacture. Based on the substance specific properties (i.e. logPow -2.25; Intertek, 2013) the substance will be able to diffuse into the dermis and due to its corrosive character also into the deeper layers of the skin, i.e. the epidermis or bloodstream layers will be crossed. Based on the low vapour pressure of the substance, an uptake via the inhalative route is not relevant. Oral exposure is not relevant based on the handling, education and safety precautions in the factory. As conclusion, only the dermal exposure route may be relevant for humans.