1H,5H-Pyrazolo(1,2-a)pyrazol-1-one, 2,3-diamino-6,7-dihydro-, dimethanesulfonate

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:

From 19 October to 17 November 2006

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: compliant to GLP and testing guideline; adequate coherence between data, comments and conclusions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Test material

Reference

Name:

Unnamed

Type:

Constituent

Details on test material:

- Name of test material (as cited in study report): R0054002C, synonym IMEXINE OBH
- Physical state: beige to yellow powder
- Purity: 99.7%
- Impurities (identity and concentrations): not indicated
- Purity test date: 20 July 2006
- Lot/batch No.: R0054002C 013 L 001, synonym 0604070001
- Expiration date of the lot/batch: 01 August 2007
- Stability under test conditions: not indicated
- Storage condition of test material: at room temperature and under nitrogen gas

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of activated sludge: water treatment plant of Evreux (France)
- Laboratory culture: CIT
- Preparation at receipt : by initially decanting and sieving the sludge to concentrate the suspended matter and remove the biggest particles. The sludge was centrifuged for 5 minutes, the supernatant was rejected and the pellet redipersed in the mineral medium.
- Storage conditions: T 22 +/- 2°C, air bubbled through the inoculum until use
- Storage length: 6 days
- Preparation of inoculum for exposure: centrifugation and redispersion of pellet in the mineral medium
- Preatreatment: no
- Concentration of sludge: 3.7 g/L
- Water filtered: no

Duration of test (contact time):

ca. 28 d

Initial test substance concentration

Initial conc.:

10 mg/L

Based on:

other: Total Organic Content

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: deionized water which contained no more than 5% of the organic carbon content
- Test temperature: 19 to 24°C
- pH: 7.27 to 7.82
- pH adjusted: no
- Continuous darkness: yes

TEST SYSTEM
- Number of culture flasks/concentration: 2
- Method used to create aerobic conditions: the test flasks were constantly aerated with CO2-scrubbed air and constantly agitated by magnetic stirring.
- Measuring equipment: titration method with 0.05 M HCl, using phenolphtalein as an indicator.


CONTROL AND BLANK SYSTEM
- Inoculum blank: two flasks
- Reference control: one flask (sodium acetate at 10.0 mg/L of TOC)
- Toxicity control: one flask (test item at 10.0 mg/L of TOC and sodium acetate at 10.0 mg/L of TOC and inoculum)

Reference substance

Reference substance:

acetic acid, sodium salt

Results and discussion

Test performance:

All validity criteria were respected:
- the blank value was < 70 mg of CO2/L at the end of the test (43.3 mg/L)
- biodegradation in the reference test was at least 60 % after 14 days
- biodegradation in the toxicity control was at least 25% after 14 days
- biodegradation values of test item replicates deviated by less than 20% at the end of the 10-day window and at the end of the 28-day period of the test

% Degradation

% Degradation 1

Parameter:

% degradation (CO2 evolution)

Value:

28

Sampling time:

17 d

Remarks on result:

other: End of the 10-day window

% Degradation 2

Parameter:

% degradation (CO2 evolution)

Value:

27

Sampling time:

28 d

Details on results:

No significant inhibition of the inoculum activity due to toxicity of the test item was noted in this test.

BOD5 / COD results

Results with reference substance:

The reference item degraded normally under the test conditions.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

other: Not readily biodegradable

Conclusions:

The biodegradation of the test item reached 28% at the end of the 10-day window on the 17th day and 27% at the end of the test. The test item was therefore not readily biodegradable in the 28-day modified Sturm test.