Bis[N-(2-hydroxyethyl)-N-methylglycinato-N,O,ON]copper

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2016-11-10 to 2016-12-09

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

Version / remarks:

July 1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Bis[N-(2-hydroxyethyl)-N-methylglycinato-N,O,ON]copper

EC Number:

300-491-4

EC Name:

Bis[N-(2-hydroxyethyl)-N-methylglycinato-N,O,ON]copper

Cas Number:

93940-93-3

Molecular formula:

C10H20CuN2O6

IUPAC Name:

bis[N-(2-hydroxyethyl)-N-methylglycinato-N,O,ON]copper

Test material form:

solid: particulate/powder

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: municipal wastewater treatment plant Breisgauer Bucht Germany, 600,000 inhabitant equivalents, predominantly domestic wastewater.
- Concentration of sludge: 4.2 g/L after drying at 105°C
- Initial cell/biomass concentration: 30 mg/L

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

20 mg/L

Based on:

TOC

Remarks:

calculated based on molecular structure

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: mineral medium according to guideline
- Additional substrate: no
- Solubilising agent: no
- Test temperature: 20.5 - 23.1°C
- pH: not registered
- pH adjusted: no
- Aeration of dilution water: 2.5 to 4.3 bubbles/second or 30-100 mL/min with CO2-free air
- Suspended solids concentration: 30 mg dry solids/L
- Continuous darkness: no, diffuse light


TEST SYSTEM
- Number of culture flasks/concentration: 3
- Method used to create aerobic conditions: aeration with CO2-free air
- Measuring equipment: Total organic carbon analyser TOC-5050A with autosampler ASI 5000A, Shimadzu.
- Details of trap for CO2 and volatile organics if used: two 250 mL glass wash bottles in series each filled with 200 mL 0.2 M NaOH, sampling through lateral connecting pieces, through butyl rubber septum using 5 mL PE syringes

SAMPLING
- Sampling frequency: on day 4, 7, 11, 14, 21 and 28
- Sampling method: 4 mL of NaOH sampled from 1st CO2-absorber flasks
- Sample storage before analysis: samples immediately closed with sealing film
- Final sampling: on day 28, 2mL of 4M HCl is added to the reactor to release CO2 dissolved in water. IC-analysis on day 29.

CONTROL AND BLANK SYSTEM
- Inoculum blank: 3 replicates
- Abiotic sterile control: no
- Toxicity control: yes, 1 replicate at 40.1 mg/L TOC
- Reference substance: 3 replicates at 30 mg/L

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

Key result

Parameter:

% degradation (CO2 evolution)

Value:

15

St. dev.:

1.05

Sampling time:

29 d

Remarks on result:

other: measured after acidification of the reactor flasks to release CO2 dissolved in water.

Remarks:

mean of 3 replicates

Details on results:

The 10-day window started on day 7. The maximal degradation observed was 16.4 %, hence, the 10-day window criteria was not met. See below for details on results.

BOD5 / COD results

Results with reference substance:

The reference substance was rapidly biodegraded, with maximal degradation of 87.1 %.

Any other information on results incl. tables

% biodegradation in the different test vessels:

Reactor	day 0	day 4	day 7	day 11	day 14	day 21	day 28	day 29
Test item, rep 1	0	5.3	9.9	14.4	14.2	11.8	16.4	16.1
Test item, rep 2	0	4.0	10.9	13.6	19.7	10.8	14.1	14.0
Test item, rep 3	0	7.1	12.1	16.9	19.8	11.5	14.9	14.9
Reference, rep 1	0	71.0	80.8	79.2	83.0	77.1	82.4	84.0
Reference, rep 2	0	77.6	79.1	80.5	85.0	80.2	86.0	87.1
Reference, rep 3	0	68.5	77.6	77.1	84.1	76.7	82.6	84.6
Toxicity control	0	39.7	41.9	46.9	48.6	48.9	53.6	54.6

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The biodegradability of the test item was examined in a CO2-evolution test according to OECD 301B. The test item was found to be not readily biodegradable with on average 15.0 % biodegradation after 28 days.

Executive summary:

The biodegradability of the test item was examined in a CO2-evolution test according to OECD 301B. After 28 days, the ultimate biodegradation was found to be 15.0 % (average of 3 replicates). The 10 -day window criteria was not fulfilled and the test item should be considered to be not readily biodegradable.

Up to 54.6 % degradation was observed in the toxicity control containing sodium benzoate and the test item. This result shows that the test item was not inhibitory to the inoculum.