1-Propanaminium, 3-amino-N-(carboxymethyl)-N,N-dimethyl-, N-C8-10 (even numbered) acyl derivs., hydroxides, inner salts

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:

2004-12-02 to 2004-12-31

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

adopted July 17, 1992

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 (e.g. location, sampling depth, contamination history, procedure): Municipal sewage treatment plant, D-31137 Hildesheim
- Pretreatment: The activated sludge was maintained in an aerobic condition by aeration for four hours and then homogenized with a mixer. The sludge was filtered and the filtrate (30 mL) was subsequently used to initiate inoculation.
- Concentration of sludge: 1E07-1E08 CFU/L in inoculum; 1E05-1E06 CFU/L in test vessels

Duration of test (contact time):

28 d

Initial conc.:

45 mg/L

Based on:

act. ingr.

Initial conc.:

11.8 mg/L

Based on:

other: TOC

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: Mineral nutrient solution acc. to OECD 301 B/CO2 Evolution Test
- Additional substrate: no
- Test temperature: 20 - 24°C, continuously stirred
- pH: 7.56 - 7.59 (test item), 7.51 - 7.59 (control), 7.86 (functional control), 7.83 (toxicity control)
- pH adjusted: no
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: 5000 mL, brown glass; fill volume 3000 mL
- Number of culture flasks/concentration: dupilcate (test item)
- Method used to create aerobic conditions: The vessels were connected to the system for the production of CO2 free air and aerated for 24 h.
- Details of trap for CO2 and volatile organics if used: The CO2 adsorption vessels were connected to the air outlets of the incubation vessels via a series of 3 gas wash bottles.

SAMPLING
- Sampling frequency: three times a week during the first ten days and thereafter twice weekly + on day 29

CONTROL AND BLANK SYSTEM
- Inoculum blank: Nutrient solution and inoculum, duplicates
- functional control: Sodium acetate, 35 mg/L (10.2 mg C/L), single replicate
- Toxicity control: Sodium acetate, 35 mg/L (10.2 mg C/L) + test item 45 mg/L (11.8 mg C/L), single replicate

Reference substance:

acetic acid, sodium salt

Key result

Parameter:

% degradation (CO2 evolution)

Value:

68

Sampling time:

11 d

Parameter:

% degradation (CO2 evolution)

Value:

81

Sampling time:

28 d

Details on results:

The 10 % level (beginning of biodegradation) was reached after an adaptation phase of 3 days. The biodegradation was rapid, the pass level of 60 % was reached on day 11. The mean biodegradation came to a maximum of 90 % after 28 days.
In the toxicity control 63 % biodegradation occurred within 14 days and came to a maximum of 85 % after 28 days. The biodegradation of the reference item was not inhibited by the test item.

Results with reference substance:

The adaptation phase of the functional control changed after 1 day into the degradation phase. The course of the degradation phase was rapid and reached a degradation rate > 60 % on day 10. The validity criterion of degradation >/=60 % after 14 d is fulfilled.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

C8-10 Alkylamidopropyl betaine is readily biodegradable in this CO2 evolution test and fulfills the 10 d window criterion. The substance is not inhibitory to microorganisms.

Executive summary:

The biodegradation of C8-10 Alkylamidopropyl betaine (35% a.i.) was investigated over a 28-day period in a CO2 Evolution Test according to OECD guideline 301 B (1992). The test medium was inoculated with non-adapted activated sludge from a sewage treatment plant mainly fed with municipal wastewater. The rate of degradation was monitored by measuring the carbon dioxide produced over the 28-d period.

The test item was tested with a concentration of 45 mg/L in duplicates, corresponding to a carbon content (TOC) of 11.8 mg C/L in the test vessels.

The biodegradation of the test item was followed by titrimetric analyses of the quantity of CO2 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 percentage CO2 production was calculated in relation to the theoretical CO2 (ThCO2) of the test item. The biodegradation was calculated for each titration time.

The 10 % level (beginning of biodegradation of the test item) was reached after an adaptation phase of 3 days. The biodegradation was rapid, the pass level of 60 % was reached already on day 11. The mean biodegradation came to a maximum of 90 % after 28 days.

 

To check the activity of the test system sodium acetate was used as functional control. The percentage of degradation of the functional control reached the pass level of 60 % after 10 days.

 

In the toxicity control containing both test and reference item a biodegradation rate of 63 % occurred within 14 days and came to a maximum of 85 % after 28 days. The biodegradation of the reference item was not inhibited by the test item in the toxicity control.

 

The test item C8-10 Alkylamidopropyl betaine is readily biodegradable in this CO2 evolution test and fulfills the 10 d window criterion. The substance is not inhibitory to microorganisms at a concentration of 45 mg/L.

Description of key information

readily biodegradable (68% after 11 d, 81% after 28 d; 45 mg test item/L); OECD Guideline 301 B (CO2 evolution test); GLP; RL1

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

The biodegradation of C8-10 Alkylamidopropyl betaine (35% a.i.) was investigated over a 28-day period in a CO2 Evolution Test according to OECD guideline 301 B (1992). The test medium was inoculated with non-adapted activated sludge from a sewage treatment plant mainly fed with municipal wastewater. The rate of degradation was monitored by measuring the carbon dioxide produced over the 28-d period.

The test item was tested with a concentration of 45 mg/L in duplicates, corresponding to a carbon content (TOC) of 11.8 mg C/L in the test vessels.

The biodegradation of the test item was followed by titrimetric analyses of the quantity of CO2 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 percentage CO2 production was calculated in relation to the theoretical CO2 (ThCO2) of the test item. The biodegradation was calculated for each titration time.

The 10 % level (beginning of biodegradation of the test item) was reached after an adaptation phase of 3 days. The biodegradation was rapid, the pass level of 60 % was reached already on day 11. The mean biodegradation came to a maximum of 90 % after 28 days.

To check the activity of the test system sodium acetate was used as functional control. The percentage of degradation of the functional control reached the pass level of 60 % after 10 days.

In the toxicity control containing both test and reference item a biodegradation rate of 63 % occurred within 14 days and came to a maximum of 85 % after 28 days. The biodegradation of the reference item was not inhibited by the test item in the toxicity control.

The test item C8-10 Alkylamidopropyl betaine is readily biodegradable in this CO2 evolution test and fulfills the 10 d window criterion. The substance is not inhibitory to microorganisms at a concentration of 45 mg/L.