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Environmental fate & pathways

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:
2018
Report Date:
2018

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent

Study design

Oxygen conditions:
anaerobic
Inoculum or test system:
activated sludge (adaptation not specified)

Results and discussion

% Degradation
Parameter:
% degradation (CO2 evolution)
Value:
< 70
Sampling time:
10 d

Any other information on results incl. tables

1     Results and Validity

1.1     Results for the Test ItemN-(4-anilinophenyl)-4-methylbenzenesulfonamide

¨            The test itemN-(4-anilinophenyl)-4-methylbenzenesulfonamideis considered as “not readily biodegradable“.

¨            The degree of biodegradation reached 11 % after 28 days.

¨            The 10-day-window was not detected.

¨            Degradation missed 60 % within 28 days, too. Therefore, the test item is considered as “not ultimately biodegradablewithin 28 days”, either.

¨            The abiotic degradation reached 4 %.

1.2     Validity

All validity parameters and values are presented in the following table:

Table9.2‑a   Validity

Parameter

Criterion

Found

Assessment

IC content of test item solution in medium

£5% of TC

0 %

valid

CO2emitted by the controls

< 70 mg/L

8.9 mg/L

valid

Difference within replicates

£20%

1.0%

valid

Degradation of positive control > 60%

≤14 days

9 days

valid

Degradation in the toxicity flask on day 14

> 25%

46.2 %

non-toxic

 


 

2     Discussion

All validity criteria were met.

Degradation behaviour of positive control and toxicity control was normal. Abiotic degradation reached 4 %. Both replicates of the test item showed very good correspondence.

Degradation values of more than 100 % were calculated. This is due to the fact that the measurement errors of test flasks and control flasks add up when using the equation proposed in the guideline.

If degradation in the toxicity flask is below 25 % after 14 days, the testitem can be considered as toxic towards the inoculum. As degradation in the toxicity flask was 46.2 % after 14 days, the test item can be stated as “not toxic towards the inoculum in a concentration of 29.4 mg/L”.

Ready degradability is defined in the guidelines as degradation surpassing 60% within 10 days after reaching a level of 10 %. Therefore, the test itemN-(4-anilinophenyl)-4-methylbenzenesulfonamidecan be considered as “not readily biodegradable”. Degradation missed 60% within 28 days, though. Therefore, the test item can be considered as “not ultimately biodegradable within 28 days, either.

No observations were made which might cause doubts concerning the validity of the study outcome.

The result of the test can be considered valid.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
not readily biodegradable
Conclusions:
when applying the 10-day-window, the test item N-(4-anilinophenyl)-4-methylbenzenesulfonamide is not readily biodegradable following OECD 301B and EU C.4-C respectively. As degradation missed 60% in the course of the test, N-(4-anilinophenyl)-4-methylbenzenesulfonamide is considered as not ultimately biodegrad-able.