N-benzyl-4-methoxy-α-methylphenethylamine

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:

from 28 April to 27 May 1999

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1999

Report date:

1999

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

N-benzyl-4-methoxy-α-methylphenethylamine

EC Number:

256-155-1

EC Name:

N-benzyl-4-methoxy-α-methylphenethylamine

Cas Number:

43229-65-8

Molecular formula:

C17H21NO

IUPAC Name:

N-benzyl-1-(4-methoxyphenyl)propan-2-amine

Test material form:

other: liquid

Details on test material:

- Name of test material (as cited in study report): TH 1165 II
- Physical state: Yellow liquid
- Lot/batch No.: 61
- Expiration date of the lot/batch: 8 April 2000 (allocated by NOTOX, 1 year after receipt of the test substance)
- Stability under storage conditions: Not indicated
- Storage condition of test material: At room temperature in the dark
- Stability in water: Not indicated
- Density: 1.05 g/ml (determined at NOTOX)

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: municipal sewage treatment plant: Waterschap de Maaskant, s-Hertogenbosch, The Netherlands.

- The sludge was kept under continous aeration until furhter treatment. The concentration of suspended solids was 4.8 g/l in the concentrated sludge (information obtained from the municipal sewage treatment plant). Before use, the sludge was allowed to settle for at least 30 minutes and the liquid decanted for use as inoculum at the amount of 10 ml/l of mineral medium.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

12 mg/L

Based on:

other: Total Organic Carbon (TOC)

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: Grade salts were added to deionised water to give stock solutions. Stock solutions were diluted in deionised water, aerated overnight with CO2 free air.
- Test temperature: 20-22°C
- pH: 7.6 (sample A) and 7.5 (sample B)
- pH adjusted: no

TEST SYSTEM
- Culturing apparatus: 2 litre all-glass brown coloured bottles
- Number of culture flasks/concentration: Test suspension: containing test substance and inoculum (2 bottles); Inoculum blank: containing only inoculum (2 bottles); Positive control: containing reference substance and inoculum (1 bottle); Toxicity control: containing test substance, reference substance and inoculum (1 bottle)
- Method used to create aerobic conditions: The test was started by bubbling CO2-free air through the solution at a rate of approx. 1-2 bubbles per second; a temporary breakdown in the aeration (<1 day) was noted on day 10. However, this breakdown was considered to have no effect on the outcome of this study.

- Measuring equipment:
- Details of trap for CO2 and volatile organics if used: The CO2 produced in each test bottle reacted with the barium hydroxide in the gas scrubbing bottle and precipitated out as barium carbonate. The amount of CO2 produced was determined by titrating the remaining Ba(OH)2 wiht 0.05 M standardized HCL.


SAMPLING
- Sampling frequency: Titrations were made every second or third day during the first 10 days, and thereafter at least every fifth day until the 28th day.
- Sampling method: Each time the CO2-absorber nearest to the test bottle was removed for titration; each of the remaining two absorbers was moved one position in the direction of the test bottle. A new CO2-absorber was placed at the far end of the series. Phenolphthalein was used as pH-indicator. On the 28th day, the pH of the test suspensions was measured and 1 ml of concentrated HCl was added to each bottle. The bottles were aerated overnight to drive off CO2 present in the test suspension. The final titration was made on day 29

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Abiotic sterile control: no
- Toxicity control: yes
- Other: see above for details

Reference substance

Reference substance:

acetic acid, sodium salt

Results and discussion

% Degradation

Parameter:

% degradation (CO2 evolution)

Value:

>= 2.8 - <= 6.6

Sampling time:

29 d

Details on results:

The total CO2 evolution in the inoculum blank at the end of the test did not normally exceed 40 mg/l. If values greater than 70 mg CO2/l are obtained, the data and experimental technique should be examined critically; the difference of duplicate values for the %-degradation of the test substance at the plateau, at the end of the test or at the end of the 10 day window, as appropriate, was less than 20

BOD5 / COD results

Results with reference substance:

The percentage degradation of the reference substance reached the level for ready biodegradability (60%) by 14 days

Any other information on results incl. tables

Equation for the calculation of mg of CO₂ produced:

The amount of 0.05 N HCl titrated is converted into mg of CO₂ produced:

mg CO₂ = (0.05 * ml HCl titrated)/2 * 44 = 1.1 * ml of HCl titrated

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

TH 1165 II was not readily biodegradable under the conditions of the modified Sturm test presently performed.