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Environmental fate & pathways

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: Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2001
Report date:
2001

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Remarks:
24th - 25th March 1997

Test material

Constituent 1
Chemical structure
Reference substance name:
Alcohols, lanolin
EC Number:
232-430-1
EC Name:
Alcohols, lanolin
Cas Number:
8027-33-6
Molecular formula:
UVCB
IUPAC Name:
Alcohols, lanolin
Constituent 2
Reference substance name:
Lanolin Alcohols
IUPAC Name:
Lanolin Alcohols
Details on test material:
Sponsor's identification: Wollwachsalkohol I Lanolinalkohol
Description: Yellow, type wax
Batch number: Eucerit 6480
Active ingredient: Wool waxalcohol
Storage conditions: 7 ± 2 °C, protected from light and moisture
Composition: Aliphates: 25.5 %
Sterines: 60.6 %
Cholesterine: 31.2 %
CH-5dien-70ne: 8.9 %
Dehydrolanosterine: 5.5 %
Lanosterine: 10.9 %

TOC: 81.6 %
ThC02: 2.99 mg CO2/mg test item
Expiry date: October 20, 2001 according to test facility SOP PEIGS

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, 0-31137 Hildesheim
- Laboratory culture: Not recorded
- Method of cultivation: Not recorded
- Storage conditions: Not recorded
- Storage length: Not recorded.

- Pretreatment:
The activated sludge is maintained in an aerobic condition by aeration for four hours and then homogenized with a mixer. The sludge is filtered and the filtrate (30 mL) is subsequently used to initiate inoculation.

- Concentration of sludge: 15 mg/L
- Colony forming units of the inoculum: 10E7 - 10E8 CFU/L
- Colony forming units in the test vessels: 10E5 - 10E6 CFU/L

- Water filtered: yes
- Type and size of filter used, if any: not stated
Duration of test (contact time):
28 d
Initial test substance concentration
Initial conc.:
15 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
CO2 evolution
Details on study design:

TEST SYSTEM
The following test solutions were prepared in 5 L brown glass bottles as incubation vessels:
• two incubation vessels for the test item concentration (P1, P2 )
• one incubation vessel for the reference item (R1)
• two incubation vessels for the inoculum control (C1, C2 )
• one incubation vessel for the toxicity control (T1)

The necessary amounts of aqua bidest., nutrient media and inoculum were placed in each of the incubation vessel. The vessels were then connected to the system for the production of CO2 free air and aerated for 24 h.

After 24 h the CO2 adsorption vessels were connected to the air outlets of the incubation vessels via a series of 3 gas wash bottles. The test and reference item concentrations were placed into the incubation vessels, the vessels made up to 3 L with CO2 free aqua bidest. and connected to the system for the production of CO2 free air.

Incubation took place in a temperature range between 22 ± 2 °C in a water bath. All vessels were stirred continuously throughout the test. On the 28th day 1 mL concentrated HCI was added to each of the vessels.

Aeration was continued for a further 24 h and on the 29th day the quantity of CO2 released in the last two gas wash bottles was determined.

- Measuring equipment:
pH-Meter, CORNING pH 240
Thermohygrograph, LAMBRECHT Tvp 3.015/3 K
Flow meter, KROHNE DUISBURG Tvp DK 800 PV

- CO2 analysis:
The total amount of CO2 produced in 28 days was analysed by titration in 12 measurements. Back titration of the residual Ba(OHh with 0.05 N HCI was carried out three times a week during the first ten days and thereafter twice weekly. On the 28th day the pH of all solutions were measured prior to acidification.

EVALUATION
The theoretical production of carbon dioxide (ThC02 ) of the test item and functional control is calculated by the carbon content (2) and the sum formula (1), respectively.

ThCO2 [mgCO2/mg] = (C-atoms x molecular weight of CO2)/molecular weight of test or reference item (1)

ThC02 [mgC02/mg] = 3.67 x TOC [mgC/mg] (2)

0.05 N HCI titrated had been converted into mg of CO2 produced:

1 mL HCI =1.1 mg CO2 (3)

The amount of CO2 produced is calculated by correcting the results of the test item and functional control for endogenous CO2 production of the control groups.

The biodegradation is calculated from the ratio theoretical CO2 production to net CO2 production in the following equation (4):

Degradation [%] = [Net CO 2 - (production x 100)]/ ThCO 2 [mgCO 2 /3L] (4)

Validity Criteria
The study was performed according to OECD 301 BI C02 Evolution Test and GLP Guidelines.
The quality criteria were fulfilled according to the guideline:
• The total CO2 production in the blank at the end of the test was less than 40 mg/L.
• The percentage degradation of the functional control reached the pass level of ≥ 60 % by day 14.
Reference substance
Reference substance:
other: Sodium acetate

Results and discussion

Preliminary study:
None conducted.
Test performance:
Not performed.
% Degradation
Parameter:
% degradation (CO2 evolution)
Value:
39
Sampling time:
28 d
Details on results:
The 10 % level (beginning of biodegradation) was reached after a adaptation period of 9 days. In the 10-day-window the mean biodegradation came to 21 %. The pass level of a biodegradation > 60 % was not reached.

The test item must be regarded to be not readily biodegradable in the 10-day-window and after 28 days.

BOD5 / COD results

Results with reference substance:
In the control group a maximum of 36.3 mg CO2/L was formed after 28 days (quality criterion: < 40 mg CO2/L after 28 days).

In order to check the activity of the test system sodium acetate was used as functional control. The percentage degradation of the functional control reached the pass level of > 60 % after 8 days. After 14 days a degradation rate of 69 % was reached. The validity criterion of the guideline is fulfilled.

Any other information on results incl. tables

Table: Biodegradation of the test item WOLLWACHSALKOHOL I LANOLINALKOHOL in comparison to the functional control and toxicity control

 

Biodegradation [%]

 

Day 6

Day 14

Day 21

 Day 28

Test Item

15 mg/L

          5

16

23

39

Functional Control 35 mg/L

 

51

 

69

 

75

 

69

Toxicity Control

15 mg/L test item + 35 mg/L reference item

 

 

26

 

 

 

49

 

 

46

 

 

50

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
other: Not readiy Biodegradable
Conclusions:
The test material attained 39 % degradation after 28 days and therefore cannot be considered to be readily biodegradable under the strict terms and conditions of OECD Guideline No 301B.
Executive summary:

The ready biodegradability was determined with a non-adapted activated sludge for the test item WOLLWACHSALKOHOL/LANOLINALKOHOL batch no. Eucerit 6480 over a test period of 28 days in the Modified Sturm Test. The study was conducted from 2001-06-07 to 2001-07-06 according to OECD 301 B/C02 evolution test in the DR.U.NOACK-LABORATORIUM FÜR ANGEWANDTE BIOLOGIE.

The test item was tested in a concentration of 15 mg/L in duplicates, corresponding to a carbon content (TOC) of 12.2 mgC/L in the test vessels.

The biodegradation of the test item was followed by titrimetric analyses of the quantity of CO2 , which was produced by the respiration of bacteria. The degradation was finished on day 28 by acidification, the last titration was made on day 29, after the soluble CO2 was turned out over a period of 24 h.

The CO2 production was calculated as the percentage of total CO2 that the test item could have theoretically produced based on carbon content. Biodegradation is therefore expressed as percentage ThC02 and was calculated for each titration of CO2.

In order to check the activity of the test system sodium acetate was used as functional control. The percentage degradation of the functional control reached the pass level of > 60 % after 8 days. After 14 days a degradation rate of 69 % was reached. The validity criterion of the guideline is fulfilled.

In the toxicity control containing both test and reference item a biodegradation rate of 40 % occurred within 14 days. The biodegradation of the reference item seemed not to be inhibited by the test item in the toxicity control.

The 10 % level (beginning of biodegradation) was reached after a adaptation period of 9 days. In the 10 -day-window the mean biodegradation came only to 21 %. The pass level of a biodegradation > 60 % was not reached neither in the 10 -day-window nor after 28 days.

The test item must be regarded to be not readily biodegradable in the 10-day-window and after 28 days. The validity criteria according to the guideline are fulfilled.

Table: Biodegradation of the test item WOLLWACHSALKOHOL I LANOLINALKOHOL in comparison to the functional control and toxicity control

 

Biodegradation [%]

 

Day 6

Day 14

Day 21

 Day 28

Test Item

15 mg/L

          5

16

23

39

Functional Control 35 mg/L

 

51

 

69

 

75

 

69

Toxicity Control

15 mg/L test item + 35 mg/L reference item

 

 

26

 

 

 

49

 

 

46

 

 

50

Conclusion:

The test material attained 39 % degradation after 28 days and therefore cannot be considered to be readily biodegradable under the strict terms and conditions of OECD Guideline No 301B.