Nitriles, C16-18 and C18-unsatd.

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

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: GLP with certificate, analysis certificate and was carried out to appropriate guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Principles of method if other than guideline:

Guideline was followed without significant deviations. (German Report)

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
-

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

Activated sludge from the sewage plant at Hifdesheim was used it is well suited as it comprises mostly municipal sewage and hardly any
industrial chemical waste. 2,1X10 4 CFU/ Ml was used to inocculate test vessels.

Duration of test (contact time):

28 d

Initial conc.:

5 mg/L

Based on:

test mat.

Initial conc.:

10 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

Stock was prepared with sonification of 15 mg/l and 30mg/l the test substance. These stocks were diluted to create test concentrations of 5 and
10 mg/l Test vessels were 5 L filled to 3 L, with reccommended OECD media added. After innoculation 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. These were used for Co2 determination.

Thco2 = 2.99 mg co2 / mg substance.

Reference substance:

other: Sodium Acetate

Preliminary study:

Bacterial toxicity study conducted prior to biodegredation test.

Test performance:

The reference substance was degraded 90% at tthe end of the test. The Co2 production in the control was lower than 50mg/3 L The temperature
range during the test stayed between 20-25ºc. The test met therefore the critical validity criteria.

Parameter:

% degradation (CO2 evolution)

Value:

94

Sampling time:

28 d

Remarks on result:

other: 5mg/l

Parameter:

% degradation (CO2 evolution)

Value:

64

Sampling time:

28 d

Remarks on result:

other: 10mg/l

Details on results:

The results suggest this chemical to be readily biodegradable up to 5 mg/l. With significant biodegredation occuring up to 10mg/l

Results with reference substance:

Satisfactory see test performance.

Biodegredation Calculation

The theoretical CO2 production (ThCO2) was calculated based on the TOC and a test of bacterial toxicity. The C02 measured was then divided by the theoretical value to give a biodegredation percentage. The amount of CO2 produced was calculated by correcting the results of the test substance and functional control for endogenous CO2 production of the control groups.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

There is reliable evidence to show that the test chemical is readily biodegradable. This study is reliable without restrictions as far as can be
established. Slightly lower biodegredation was measured at the higher test concentration. However at environmental concentrations it can be
concluded with a good degree of certanty that this substance would degrade fully.

Executive summary:

The test substance could be regarded to be readily biodegradable. Both test substanced achieved over 60% biodegredation in 28 days.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Reliable with restrictions lacking analysis certificate only.

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Principles of method if other than guideline:

Guideline was followed without significant deviations.

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
-

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

Activated sludge from the sewage plant at Hifdesheim was used it is well suited as it comprises mostly municipal sewage and hardly any
industrial chemical waste.

Duration of test (contact time):

28 d

Initial conc.:

13 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

Stock was prepared with sonification of 13 mg the test substance. Test vessels were 5 L filled to 3 L, with reccommended OECD media added. After i
nnoculation 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. These were used for Co2 determination.

Reference substance:

other: Sodium Acetate

Preliminary study:

Bacterial toxicity study conducted prior to biodegredation test.

Test performance:

In order to check the activity of the study system sodium acetate was used as functional control. The functional control was degraded to 72 % after
13 days and therefore the quality criteria of "degradation"> 60 % after 14 days was fulfilled. The toxicity control the degradation came to 71
% after 13 days in a 10-day window and reached a maximum of 85 % after 28 d. In the toxicity control the degradation came to a rate of 71 %
after 13 days and reached a maximum of 85 [%I after 28 days.

Key result

Parameter:

% degradation (CO2 evolution)

Value:

72

Sampling time:

28 d

Details on results:

The results suggest this chemical to be readily biodegradable

Results with reference substance:

Satisfactory see test performance.

Biodegredation Calculation

The theoretical CO2 production (ThCO2) was calculated based on the TOC and a test of bacterial toxicity. The C02 measured was then divided by the theoretical value to give a biodegredation percentage. The amount of CO2 produced was calculated by correcting the results of the test substance and functional control for endogenous CO2 production of the control groups.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

There is reliable evidence to show that the test chemical is readily biodegradable. This study is reliable with restrictions and could achieve a
reliability 1 score if an analysis certificate is made available.

Executive summary:

In case of the test substance the 10 % pass level was reached after 4 days adaptation phase. In the 10-day window the test substance reached a degradation rate of 58 to 59 %) very close to the recommended pass level of 60%. After 28 days a mean degradation 72 % was reached. The test substance could be regarded to be readily biodegradable.

Description of key information

Tallow Nitrile is readily biodegradable

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Type of water:

freshwater