Glycine hydrochloride

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

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 is a dibasic acid and disintegrates in aqueous solution to glycine (CAS 56-40-6), the source substance, and hydrochloride. The buffer capacity of test solutions prepared according to OECD guideline 202 is sufficient for neutralising hydrochloride in the used concentrations. Consequently, glycine remains as the only active ingredient. Hence, only glycine will be present in the aqueous test solutions regardless whether gylcine itself or glycine hydrochloride was used as test material, 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 acute toxicity test with Daphnia magna (reference 6.1.3-1), had a analytical purity of > 90 %. No information on impurities is available. The target substance glycine hydrochloride 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, i.e. an acute toxicity study with Daphnia magna was available for glycine. Glycine was tested in an study according to OECD 202. This study revealed an EC50 of > 220 mg/L. 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

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 220 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 220 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Description of key information

In a read across with the source substance glycine (CAS 56-40-6), the EC50 (48h) and the NOEC (48h) of the target substance glycine hydrochloride (CAS 6000-43-7) was determined to be > 220 mg/L and >= 220 mg/L, respectively.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

220 mg/L

Additional information

No data on toxicity to aquatic invertebrates were available for the 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

To assess the toxicity of the test item to Daphnia magna, a semi-static acute toxicity test according to OECD guideline 202 and EU Method C.2 was conducted in compliance with GLP principles. Daphnids were exposed to test item concentrations of 0 (negative control), 10, 22, 45, 100, 220 mg/L (nominal) over a test duration of 48 hours. As a result, the EC50 (48h) of the test item was determined to be > 220 mg/L and the NOEC (48h) was determined to be >= 220 mg/L. In conclusion, no effects occurred up to the highest test concentration of 220 mg/L (nominal). The mean measured concentrations were within 20% of nominal values. The test is regarded as valid (reference 6.1.3-1).

Conclusion

The acute toxicity of glycine hydrochloride (CAS 6000-43-7) to aquatic invertebrates was assessed in a read across to the structural analogue glycine (CAS 56-40-6). Based on a acute toxicity test according to OECD guideline 202 and EU Method C.2 (reference 6.1.3-1), the EC50 (48h) and NOEC (48h) of the target substance glycine hydrochloride was determined to be > 220 mg/L and >= 220 mg/L, respectively.