Reaction product of: 2-[[4-amino-2-ureidophenylazo]-5-[(2-(sulfooxy)ethyl)sulfonyl]]benzenesulfonic acid with 2,4,6-trifluoropyrimidine and partial hydrolysis to the corresponding vinylsulfonyl derivative,mixed potassium/sodium salt

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1997

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Yellow MGi 1301

IUPAC Name:

Yellow MGi 1301

Test material form:

solid

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Duration of test (contact time):

35 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

140 mg/L

Based on:

DOC

Remarks:

nominal value

Initial test substance concentration 2

Initial conc.:

27.5 mg/L

Based on:

DOC

Remarks:

measured value

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

DOC removal

Reference substance

Reference substance:

aniline

Results and discussion

% Degradation

Parameter:

% degradation (DOC removal)

Value:

52

Sampling time:

35 d

Any other information on results incl. tables

Expressed as percentage DOC removal, average degradation was only 8 % after 27 days, 46 and 48 % after 28 and 29 days, respectively, and 52 % after 35 days of exposure to activated sludge from a domestic waste water treatment plant.

Likewise, in the abiotic control (flask no. 6) containing the test article and sterile medium (without inoculum) practically no DOC-removal was noted during the first 27 days of exposure. Starting on exposure day-27 the DOC concentration decreased from 27.2 mg/l to 17.3 mg/l on day-35. Expressed as percentage DOC-removal, values in the range from 0 to 9 % were noted during the first 27 days of exposure, and 44, 50 and 42 % were noted after 28, 29 and 35 days of exposure, respectively without activated sludge under abiotic conditions.

These results indicate that YELLOW MGi 1301 was biotically degraded by 52 % after 35 days of exposure, and that the sudden start of biodegradation after 28 days was additionally facilitated by the spontaneous abiotic degradation of the test article under the present test conditions.

ln the procedure controls (flasks no. 3 and 4) containing the reference compound Aniline and inoculum, Aniline was readily biodegraded by an average of 92 % within 14 days of exposure, and by 96 % by exposure day-28; thus confirming suitability of the activated sludge.

ln the toxicity control containing the test article (40.5 % as DOC), the reference compound (59.5 % as DOC) and inoculum, the initial DOC concentration of 32.6 mg/l measured on day-0 decreased by 64 % within 14 days of exposure; thus, according to the test guidelines the test article can be assumed to not be inhibitory to activated sludge because degradation was > 35 % within 14 days.

Applicant's summary and conclusion

Conclusions:

Ready Biodegradabilty (35 d) = 52 % DOC removal