Betaine hydrochloride

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

In the assessment of betaine hydrochloride (C5H12NO2.Cl, CAS 590-46-5), a read-across approach is followed based on the information available for betaine (C5H11NO2, CAS 107-43-7). This read-across strategy is based on the hypothesis that the betaine moiety is the driver for the ecotoxicological and toxicological effects of both substances.
The read-across hypothesis is justified by the immediate dissociation of betaine hydrochloride to betaine and hydrogen and chloride ions upon dissolution in aqueous media. Both betaine and betaine hydrochloride are highly soluble (>400 g/L). Exposure to the non-common cations (H+ and Cl-) does not influence the prediction of the (eco)-toxicity at relevant concentrations because both elements are abundantly present in natural environments and emissions from this substance do not significantly increase their overall exposure concentration.

Further information is included as attachment in section 13 of IUCLID.

Reason / purpose for cross-reference:

reference to other study

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across: supporting information

Duration of test (contact time):

<=

Parameter:

% degradation (CO2 evolution)

Value:

<= 88

Sampling time:

28 d

Remarks on result:

other: 87 % mineralisation was achieved within 14 d

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The substance betaine is readily biodegradable and reaches 88 % mineralisation after 28 d. Biodegradability was determined according to the OECD 301 B guideline method to study mineralisation of the substance by measuring the CO2 evolution. Activated sludge was adapted from the domestic waste water treatment plant. The concentration of the activated sludge was 30 mg dry matter/L.
According to a read-across approach based on the rapid dissociation of betaine hydrochloride to betaine and hydrogen and chloride ions upon dissolution in aqueous media, it is concluded that the results for betaine are also applicable to betaine hydrochloride because the released protons and chloride ions will not affect the result for the concentration and the medium tested. Therefore, betaine hydrochloride is also to be considered as readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

[Type of water: freshwater]