4-methoxybenzyl alcohol

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

11 June 2013 and 01 October 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 310 (Ready Biodegradability - CO2 in Sealed Vessels (Headspace Test)

Version / remarks:

2006

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: Municipal sewage treatment plant, Hildesheim, Germany
- Pretreatment: The activated sludge was washed twice with chlorine free tap water. After the second washing the settled sludge was resuspended in mineral salts medium and was maintained in an aerobic condition by aeration for 2.5 hours. Thereafter the sludge was homogenized with a blender. After sedimentation the supernatant was decanted and was maintained in an aerobic condition by aeration with CO2-free air for 5 days. 10 mL/L were used to initiate inoculation.
- Colony forming units in the test solution: 10E+5 - 10E+8 CFU corresponding to 10E+2 - 10E+5 CFU/mL

Duration of test (contact time):

28 d

Initial conc.:

20 mg/L

Based on:

test mat.

Initial conc.:

13.8 mg/L

Based on:

other: Carbon content in the vessel

Initial conc.:

0.69 other: mg C/mg test item

Based on:

other: TOC

Parameter followed for biodegradation estimation:

inorg. C analysis

Details on study design:

TEST CONDITIONS
- Composition of medium: according to OECD guideline
- Test temperature: 19.0 - 21.0 °C, up to 26.0 °C on day 25

TEST SYSTEM
- Culturing apparatus: Headspace flasks
- Number of culture flasks/concentration: 3 (on day 28, 5 replicates)
- Measuring equipment: Carbon analyser (Multi N/C 3100)
- Test performed in closed vessels due to significant volatility of test substance: Yes

SAMPLING
- Sampling frequency: Analysis was carried out at test start, twice in the first two weeks and thereafter every 7 days.

CONTROL AND BLANK SYSTEM
- Inoculum blank: mineral medium containing only inoculum
- Toxicity control: mineral medium containing test substance (20 mg/L), reference substance (30 mg/L) and inoculum

Reference substance:

benzoic acid, sodium salt

Preliminary study:

none

Key result

Parameter:

% degradation (inorg. C analysis)

Value:

87

Sampling time:

28 d

Remarks on result:

other: 95% CI: 85-89%

Details on results:

The biodegradation of the test item came to 87 % after 28 days. The 10 % level (beginning of biodegradation) was reached on day 3, the pass level of 60 % within the 10-day-window on day 5. In the toxicity control, containing test and reference item, a biodegradation of 92 % was determined after 28 days. The biodegradation of the reference item was not inhibited by the test item in the toxicity control.

Results with reference substance:

The functional control (sodium benzoate) reached the pass level of 60 % after 3 days and came to 94 % after 28 days.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The test item is readily biodegradable as the pass level of 60 % degradation was reached in a 10-d-window within the 28 days period of the study.

Executive summary:

The ready biodegradability of the test item was determined with a non adapted activated sludge over a test period of 28 days in the Headspace Test according to OECD 310 and under GLP. The test item was tested at a concentration of 20 mg/L in triplicates, corresponding to a carbon content of 13.8 mg C/L. The biodegradation of the test item was followed by TIC analyses of the quantity of CO2 produced by the respiration of bacteria. The biodegradation of the reference item was not inhibited by the test item in the toxicity control. The biodegradation came to 87 % after 28 days. In conclusion, the test item is readily biodegradable as the pass level of 60 % degradation was reached in a 10-d-window within the 28 days period of the study.

Description of key information

The test item is readily biodegradable as the pass level of 60 % degradation was reached in a 10-d-window within the 28 days period of the study.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

The ready biodegradability of the test item was determined with a non adapted activated sludge over a test period of 28 days in the Headspace Test according to OECD 310 and under GLP. The test item was tested at a concentration of 20 mg/L in triplicates, corresponding to a carbon content of 13.8 mg C/L. The biodegradation of the test item was followed by TIC analyses of the quantity of CO2 produced by the respiration of bacteria. The biodegradation of the reference item was not inhibited by the test item in the toxicity control. The biodegradation came to 87 % after 28 days. In conclusion, the test item is readily biodegradable as the pass level of 60 % degradation was reached in a 10-d-window within the 28 days period of the study.