N-methyl-m-toluidine

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

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 835.3110 (Ready Biodegradability)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

2-tert-butyl-1,4-dimethoxybenzene

EC Number:

244-216-5

EC Name:

2-tert-butyl-1,4-dimethoxybenzene

Cas Number:

21112-37-8

Molecular formula:

C12H18O2

IUPAC Name:

2-tert-butyl-1,4-dimethoxybenzene

Specific details on test material used for the study:

Commercial name: Methyl Toluidine
Givaudan Code No.: 1478143
Aspect: pale yellow to yellow liquid
Lot No.: SC00019684
Expiration date: December 25, 2018

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

Fresh activated sludge from a biological waste water plant treating predominantly domestic sewage (Bois-de-Bay, Satigny, Switzerland) was used.
The sludge is collected in the morning, washed three times in the mineral medium (by centrifuging at 100 g for 10 minutes, discarding the supernatant and resuspending in mineral medium) and kept aerobic until being used on the same day.

Duration of test (contact time):

49 d

Initial test substance concentration

Initial conc.:

30 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

Test performance:

Degradation of sodium benzoate exceeded 40% after 7 days and 65% after 14 days: the activity of the inoculum was thus verified (validity criterion).
The repeatability validity criterion (not more than 20% difference between replicates) is fulfilled. Therefore, the test is considered valid.

% Degradation

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Details on results:

Methyl Toluidine undergoes no biodegradation after 28 days in the test conditions.
Methyl Toluidine did significantly inhibit the intrinsic respiration of the inoculum at the test concentration. Toxicity towards the inoculum can therefore not be excluded.
Methyl Toluidine should be regarded as not readily biodegradable according to this test.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

Methyl Toluidine undergoes no biodegradation after 28 days in the test conditions.
Methyl Toluidine did significantly inhibit the intrinsic respiration of the inoculum at the test concentration. Toxicity towards the inoculum can therefore not be excluded.
Methyl Toluidine should be regarded as not readily biodegradable according to this test.