Dihydrogen bis[monoperoxyphthalato(2-)-O1,OO1]magnesate(2-)

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1982

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

according to guideline

Guideline:

EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)

Version / remarks:

modified Sturm test according to method 5-2 Biotic degradation - Part C: EEC Ecotoxicity directive 79/831

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

Test material: Magnesium-monoperoxyphthalate-hexahydrate, H 48

Oxygen conditions:

aerobic

Inoculum or test system:

sewage, domestic (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge: Wastewater treatment plant at the town of Etampes (sample from 17.11. 1981)
- Initial cell/biomass concentration: 2- 3 · 106 germs/mL

Duration of test (contact time):

28 d

Initial conc.:

10 mg/L

Based on:

test mat.

Initial conc.:

20 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Test temperature: 21 ± 1 °C

SAMPLING
- Sampling frequency: On days 0, 1, 4, 5, 6, 7, 8, 11, 13, 15, 18, 20, 22, 25 and 28

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes

Reference substance:

aniline

Remarks:

20 mg/L

Reference substance:

other: D-Glucose monohydrate 20 mg/L

Key result

Parameter:

% degradation (CO2 evolution)

Value:

80 - 100

Sampling time:

28 d

Results with reference substance:

100 % both for glucose (in 20 days) and aniline (in 25 days). The degradation, given in the graph, was > 60% within 7 days for both reference substances

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Executive summary:

The test on ready biodegradability of MMPP in water was performed according to the modified Sturm test according to method 5-2 Biotic degradation - Part C: EEC Ecotoxicity directive 79/831.

The test substance was tested at concentrations of 10 and 20 mg/L. It is not stated whether these values relate to the test item or DOC as recommended in the guideline. However, as the test was conducted 1982 it can be assumed that the concentration is related to test item.

All setups were inoculated with aerobic wastewater flora from the wastewater treating plant at the town of Etampes (concentration 2 – 3 · 10⁶ germs/mL). However, limited documentation of the test system and test conditions.

After 28 days the percentage degradation was 83 - 100 %. No information on the 10-day window criterion was given in the study. However, using the raw data, this criterion was fulfilled for the concentration of 20 mg/l.

A complete, detailed discussion of the validity criteria is not possible due to limited documentation. However, high degradation was observed for two reference substances within 7 days. As a result of the effect values described in the study according to OECD 209, an inhibition may be not expected for the applied test substance concentration. This is in agreement with the results of this study (inhibition was not observed). Secondly, volatility of MMPP from aqueous solutions can be neglectedand therefore this property has no influence on the result.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Type of water:

freshwater