N,2-dimethyl-N-phenylbutyramide

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:

other: Guideline study, to GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

modified by use of sealed vessels for assessment of volatile substances

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

N,2-dimethyl-N-phenylbutyramide

EC Number:

282-817-4

EC Name:

N,2-dimethyl-N-phenylbutyramide

Cas Number:

84434-18-4

Molecular formula:

C12H17NO

IUPAC Name:

N,2-dimethyl-N-phenylbutanamide

Test material form:

other: solid

Details on test material:

Name: Gardamide
Manufacturer's Code: 638014
Sample Description: White somewhat sharp smelling solid
Purity: Non-GLP 99.0%
Molecluar weight: 191.0 g/mol
% Carbon: calculated 75.4%
Hazards: Not known. Avoid contact with skin or eyes
Storage: Store at room temperature in the dark

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

Secondary effluent from an unacclimatised activated sludge plant at URL North.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

10 mg/L

Based on:

test mat.

Details on study design:

The test used was the sealed vessel test which is suitable for determining the ready biodegradability and ultimate biodegradability of organic substances. The test is conducted in 160 mL vessels (hypovials) containing 100 mL mineral salts medium innoculated with secondary effluent and the respective test or reference substance. Mulitple vessels are prepared per substance sealed with a butyl rubber septum and an aluminium crimp seal. The headspace in each vessel has a volume of 60 mL and, when filled with air, contains approximately 6 times the mass of oxygen required for the complete oxidation of the substance.

The sealed vessels are incubated at 20 °C on a rotary shaker. At intervals during the 28 day test period a vessel is removed and the concentration of carbon dioxide in the headspace gas is determined. The seal is then broken and the concentration of the inorganic carbon in the test medium is also determined. The total inorganic carbon in the vessel is calculated and corrected by subtracting the total inorganic carbon produced in a control. The control vessels are identical to the test vessels except for the omission of the test substance, the extent of mineralisation can be determined.

Reference substance

Reference substance:

other: benzyl alcohol

Results and discussion

% Degradation

% Degradation 1

Parameter:

% degradation (inorg. C analysis)

Value:

2

Sampling time:

7 d

% Degradation 2

Parameter:

% degradation (inorg. C analysis)

Value:

2.6

Sampling time:

11 d

% Degradation 3

Parameter:

% degradation (inorg. C analysis)

Value:

4.6

Sampling time:

17 d

% Degradation 4

Parameter:

% degradation (inorg. C analysis)

Value:

0

Sampling time:

24 d

% Degradation 5

Key result

Parameter:

% degradation (inorg. C analysis)

Value:

0.7

Sampling time:

28 d

BOD5 / COD results

Results with reference substance:

Benzyl alcohol was chosen as a reference substance because it has previously been shown to be readily biodegradable in the Sealed Vessel Test System. Benzyl alcohol achieved 96.3% biodegradation after 28 days and the 60% 'pass' level was reached within 10 days of exceeding the 10% level. Consequently benzyl alcohol can be classified as readily biodegradable thereby confirming the suitability of the inoculum and the culture condidtions of this study.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

In a guideline study, to GLP, Gardamide at 10 mg/L was not readily biodegradable in activated sludge (0.7% biodegradation at day 28).

Executive summary:

Gardamide was evaluated for ready biodegradability in a sealed CO2 study (modified OECD 301 B) and to GLP. Gardamide failed the test and therefore cannot be classed as being readily biodegradable.