L-Glutamic acid, N-coco acyl derivs., disodium salts

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: Non-GLP guideline study with no information on the inoculum. No information if all validity criteria were fulfilled.

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 E (Ready biodegradability: Modified OECD Screening Test)

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

- - Source of inoculum/activated sludge: not specified

Duration of test (contact time):

28 d

Initial conc.:

5 - 40 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

TEST CONDITIONS
- Composition of medium: anorganic nutrient solution containing micronutrients and essential vitamines
- Test temperature: 20 - 25 °C
- Continuous darkness: yes

TEST SYSTEM
- Other: The test solution was placed on a mechanical shaker

SAMPLING
- Sampling frequency: Samples were taken after 7, 14, 21, 27 and 28 days.

CONTROL AND BLANK SYSTEM
- Inoculum blank: Yes, a trial without the test or reference substance was conducted

Reference substance:

benzoic acid, sodium salt

Parameter:

% degradation (DOC removal)

Value:

94.4

Sampling time:

28 d

Details on results:

The test substance reached a biodegradation of 94.4% within a test period of 28 days. The 10 day-window was met. Thus, the test substance is readily biodegradable according to OECD criteria.

Results with reference substance:

The reference substance was biodegraded to 97.9% within 28 days.

Table 1: Biodegradation of reference and test substance in % DOC removal throughout the test period of 28 days

Days	Reference substance	Test substance
7	93.0	81.4
14	97.8	90.5
21	97.2	93.0
27	97.8	95.5
28	97.9	94.4

Validity criteria fulfilled:

not specified

Interpretation of results:

readily biodegradable

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

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

Adequacy of study:

key study

Reason / purpose for cross-reference:

read-across source

Parameter:

% degradation (CO2 evolution)

Value:

94.4

Sampling time:

28 d

Description of key information

Readily biodegradable: 94.4% in 28 days (OECD 301E, read across)

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

No studies investigating the ready biodegradability of l-Glutamic acid, N-coco acyl derivs., disodium salts (CAS No. 68187-30-4) are available. Thus, available data for the source substance l-Glutamic acid, N-coco acyl derivs., monosodium salts (CAS No. 68187-32-6) was used in a read-across approach. The read across is considered valid as both substances are structurally identical (solely differing in the degree of deprotonation being di- and monosodium salts, respectively), which assume very similar physico-chemical properties resulting in identical environmental behavior and ecotoxicity.

The read-across key study was performed according to OECD guideline 301E using polyvalent microorganisms as inoculum (Hoechst, 1989). Test substance concentrations of 4 – 50 mg DOC/L were tested. The test substance showed a biodegradation of 81.4% after 7 days and 94.4% after an incubation period of 28 days. Thus, the test substance is readily biodegradable according to OECD criteria. Due to the very high structural similarity, this result can also be considered for l-Glutamic acid, N-coco acyl derivs., disodium salts (CAS No. 68187-30-4).