3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid

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:

2007-07-18 to 2007-08-17

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study with analytical monitoring

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 A (Ready Biodegradability: DOC Die Away Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source and Preparation of inoculum for exposure: Municipal activated sludge from the wastewater treatment plant of the city Mannheim/Baden Württemberg (Germany). It was collected on 19 July 2007 from the aeration tank of the plant and aerated in the laboratory until use. An appropriate aliquot of the activated sludge suspension was sieved with a finely woven mesh (mesh size about 1 mm), washed with tap water, and pre-aerated for about 24 hours. The sludge of this suspension was adjusted to a concentration of 6.0 g/L of dry weight and then added to the test vessels to obtain a sludge
concentration of 30 mg/L dry substance.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

20 mg/L

Based on:

DOC

Initial test substance concentration 2

Initial conc.:

47 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

TEST CONDITIONS
- Composition of medium: According to guideline
- Test temperature: 22 ± 2 °C
- Aeration of dilution water: Vessels were shaken using orbital shakers for aeration
- Sludge concentration: 30 mg/L dry substance

TEST SYSTEM
- Culturing apparatus: 2L conical flaks
- Number of culture flasks/concentration: 2
- Measuring equipment: TOC-analyzer Shimadzu TOC-5000A

SAMPLING
- Sampling frequency: Smapling on days 0, 1, 3, 5, 7, 10, 14, 17, 21, 24, 27, 28
- Sample storage before analysis: None, samples were analyzed on the day of sampling

CONTROL AND BLANK SYSTEM
- Inoculum blank: Yes
- Abiotic control: Yes
- Toxicity control: Yes

Reference substance

Reference substance:

aniline

Results and discussion

% Degradation

Parameter:

% degradation (DOC removal)

Value:

< 10

Sampling time:

28 d

BOD5 / COD results

Results with reference substance:

Biodegradation degree of the reference substance after 14 days: 98 % DOC

Any other information on results incl. tables

Biodegradation degree in the inhibition control after 14 days: 51% DOC

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

other: Poorly biodegradable