Bis(6-methylalkyl-5-en-2-yl)dihydro-heteropolycycle

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:

2007-09-14 until 2008-01-08

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

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

Test material form:

liquid

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Activated sludge was used as inoculum (concentration in the test 25.1 mg dry matter/L). Activated sludge from a biologie sewage treatment plant was used . The chosen plant is treating mostly domestic sewage.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

20 mg/L

Based on:

TOC

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

The medium was prepared from the stock solutions. The inoculum was taken from its source, washed, aerated and the dry matter was determined. The test vessels were filled with medium and inoculum. Then all flasks were aerated for 24 hours with purified, CO2-free, moistened air to purge the system of CO2. The test was performed with a nominal start concentration of 20 mg organic carbon/L.
The test vessels were aerated with CO2-scrubbed air. Magnetic stirrers were used to prevent deposition of inoculum. The emitted CO2 was trapped in 0.25 m-NaOH. Two scrubbers containing 100 mL each were connected in series to the test vessels. The initial IC value of the 0.25 m-NaOH was determined as 6.85 ppm.
From each front scrubber flask, nine samples were taken in order to determine the emitted CO2. (on days 2, 4, 6, 8, 11 , 14, 18, 22, and 29). The sampie volume was 1 mL. The resulting change in the volume of the front flask was considered in the calculation of emitted CO2. On day 28, 5 mL HCI 2-m were added to each test flask in order to drive off dissolved CO2. On day 29, samples from both scrubber flasks were taken.

Reference substance

Reference substance:

aniline

Results and discussion

% Degradation

Key result

Parameter:

% degradation (CO2 evolution)

Value:

79

Sampling time:

28 d

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The test item is considered as "readily biodegradable". The degree of biodegradation reached 79 % after 28 days. The 10-day-wlndow began on day 4, at its end, 60% were calcu!ated, reaching the pass level of 60 % given in the OECD guideline 301 B. The abiotic degradation reached 19 %.

Executive summary:

The test item was tested using a concentration of nominally 20 mg organic carbon/L (corresponding to 26.6 mg test item) in test medium tollowing OECO 301 B and EU-Method C.4-C. Aniline was chosen as reference item. Activated sludge was used as inoculum (concentration in the test 25.1 mg dry matter/L). The test was left running for 28 days.

All validity criteria were met. Degradation of the reference item was 75 % after six days.

The degree of biodegradation reached 79 % after 28 days. The 10-day-window began on day 4, at its end, 60% were calcu!ated, reaching the pass level of 60 % given in the OECD guideline.

Therefore, applying the 10-day-window, the test item is readily biodegradable following OECD 301 B/EU C.4-C