Glycine 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:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The target substance glycine hydrochloride (CAS 6000-43-7) is a dibasic acid and disintegrates in aqueous solution to glycine (CAS 56-40-6), the source substance, and hydrochloride. Hydrochloride is an anorganic molecule and is not biodegradable. Regardless whether glycine or glycine hydrochloride is used as test material in a ready biodegradability study according to OECD guideline 301 C, the derived percentage of biodegradation is solely based on the biodegradation of glycine, which allows the read across between the two test materials.

2. SOURCE AND TARGET CHEMICAL
The source substance glycine (CAS 56-40-6), which was used in the ready biodegradability test (reference 6.1.5-1), had a analytical purity of >= 99 %. No information on impurities is available. The target substance glycine hydrochloride (CAS 6000-43-7) has a purity of >= 99 %. The amount of impurities was determined to be <= 1 %. Thus, the purity of the test materials is comparable.

3. ANALOGUE APPROACH JUSTIFICATION
Experimental data on biodegradability was available for glycine. Glycine was tested in an study according to OECD 301 C. As a result, glycine was determined to be readily biodegradable. The information given on glycine is considered to be sufficient to cover the required endpoint information for the target substance glycine hydrochloride.

Reason / purpose for cross-reference:

read-across source

Key result

Parameter:

% degradation (O2 consumption)

Value:

>= 76 - <= 82

Sampling time:

14 d

Interpretation of results:

readily biodegradable

Description of key information

In a read across with the source substance glycine (CAS 56-40-6), the target substance glycine hydrochloride (CAS 6000-43-7) was determined to be readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

No data on biodegradability were available for the substance glycine hydrochloride (CAS 6000-43-7) itself. Therefore, a read across to the close structural analogue glycine (CAS 56-40-6) was conducted.

Key study

The ready biodegradability of glycine (CAS 56-40-6) was investigated in a MITI test using a mixture of sewage, soil and water from 10 collection sites as inoculum. The test was conducted according to OECD guideline 301 C. After a contact time of 14 days, glycine attained 76-82% degradation based on oxygen consumption and 96-100% degradation based on DOC removal. HPLC analysis of the substance confirmed full degradation of glycine. Hence, glycine can be determined as readily biodegradable according to the OECD criteria (reference 5.2.1 -1).

Conclusion

The biodegradability of glycine hydrochloride (CAS 6000-43-7) was assessed in a read across to the structural analogue glycine (CAS 56-40-6). Based on a ready biodegradability test according to OECD guideline 301 C (reference 5.2.1-1), the target substance glycine hydrochloride was determined to be readily biodegradable.