Choline hydrogen carbonate

Endpoint summary

Additional information

Abiotic degradation

In general, phototransformation and hydrolysis are the main abiotic degradation pathways for a substance. Choline hydrogen carbonate is neither susceptible for phototransformation in air, water and soil nor for hydrolysis under environmental conditions. Experimental investigations are not triggered for a registration under REACH.

Biotic degradation

The read-across substance Choline chloride (CAS 67-48-1) was found to be "readily biodegradable" (BASF AG, 1984). The read-across procedure is considered as valid based on the structural and characteristical similarities to the target substance Choline hydrogen carbonate. Therefore, also Choline hydrogen carbonate is considered as "readily biodegradable" and no further investigations for biotic degradation are triggered. The substance will be degraded when entering the environmental compartment and therefore will not be persistent.

Bioaccumulation

Bioaccumulation in aquatic organisms is not expected for Choline hydrogen carbonate. It was not possible to determine the logPow experimentally, however, based on the substance characteristics, an experimental investigation can be waived in accordance to REACH, Annex IX, Section 9.3.2, column 2. Since the Bioconcentration factor (BCF) is an important parameter, a read-across is intended to the structural analogue Choline chloride (CAS 67-48-1). The BCF was predicted as 3.16 L/kg using the scientifically accepted QSAR software BCFBAF v3.01 (Chemservice S.A., 2013). Thus, for Choline chloride as well as for the target substance no potential to bioaccumulate in aquatic biota is expected.

Transport and distribution

Soil adsorption of Choline hydrogen carbonate was not investigated experimentally. The logPow could not be determined experimentally, however, based on the on the physico-chemical properties and the structural composition of the substance, only a low adsorption potential is expected. Therefore, in accordance to REACH, Annex IX, Section 9.3.3, column 2, an experimental investigation can be waived. The organic carbon-normalized sorption coefficient (Koc) is an important parameter for the chemical safety assessment of a substance and can be predicted with the scientifically accepted QSAR software KOCWIN v2.00 (EPIWIN software by US-EPA). Since Choline hydrogen carbonate is lying out of the domain, such a prediction is not possible. Therefore, the prediction result for the reliable read-across substance Choline chloride (CAS 67-48-1) is taken into account (Chemservice S.A., 2013). The traditional method gives a Koc of 3.736E-3 L/kg, whereby the MCI method, which is taken more seriously into account, reveals a value of 1.438 L/kg as result. An important note is the fact that choline chloride is a Quaternary Ammonium Compound (QAC) and therefore the adsorption will depend on the cation-exchange capacity of the sorbent and a variety of other parameters. Further confirmation, that the substance has no soil adsorption capacity is reported in the OECD SIDS Report for Choline chloride (2005). A prediction with SRC PCKOWIN v1.66 is reported therein, resulting in a Koc 2.34 (BASF AG, 2003).

Although the Henry´s Law constant (HLC) is no mandatory requirement under REACH, it is an important parameter for the derivation of the PNECsoil using the Equilibrium Partitioning Method (EPM). Also for this value, it was not possible to perform a QSAR prediction for Choline hydrogen carbonate. Concerning the read-across substance Choline chloride (CAS 67-48-1), the Bond Method of the computer program HENRYWIN from US-EPA a Henry´s Law Constant of 2.05E-11 Pa*m3/molwas calculated for the substance Choline chloride at 25 °C.The Group Method showed an “incomplete Result”.For details and justification of the read-across procedure, please refer to the separate read-across statement (Chemservice S.A., 2013).