Dimethyl(octyl)amine

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:

1996

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

according to guideline

Guideline:

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

Deviations:

not specified

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)

Deviations:

not specified

GLP compliance:

not specified

Specific details on test material used for the study:

not specified. To clarify, test material in report described as Farmin DM08P is N,N-dimethyloctan-1-amine (AP-1)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

two vessels prepared containing mineral salts medium, activated sludge (30 mg solids/I; obtained from a domestic sewage
works at Oakley, Suffolk) to give a nominal test concentration of 10 mgC/I. Control vessels comprised two containing inoculated mineral salts medium alone and one containing inoculated mineral salts medium plus sodium benzoate (10 mgC/I).

Sodium benzoate was degraded by 60% after five days and 91% after 29 days. Cumulative CO2 production in the controls after 29 days (91.6 and 90.6 mgCO2) was within the acceptable range for this assay system (recommended maximum = 120 mgC02 for a three litre culture).

The pH oftest mixtures measured at the start and end of the test ranged between 7.6 and 7.7. Temperatures of the test area typically ranged from 19.7 °C to 24.0 °C. Although the lowest value falls outside the minimum recommended for this assay (20°C) it is not
thought to be significant or to have affected the integrity of the test. These results confirm that the inoculum was viable and that the test was valid.

Duration of test (contact time):

29 d

Initial conc.:

10 other: mg Carbon/Litre

Based on:

other: carbon content of AD-1

Details on study design:

The ready biodegradability of Fannin DM08P was assessed in the carbon dioxide (C02) Evolution Test (Modified Sturm Test, Procedure C.4-C of the Annex to Directive 92/69/EEC; OECD Procedure 30 lB).

The total organic carbon (TOC) content of an aqueous solution of Farmin DM08P was determined by using an 0 and I Model 700 organic carbon analyser.

The mean TOC content was 63.3%; this estimate of the carbon content of Farmin DM08P was used to establish test concentrations in the subsequent bacterial inhibition assay and Modified Sturm tests.

A five-day bacterial inhibition test was performed under the conditions of the ClosedBottle Test (EC Procedure C.4-E, OECD Procedure 301D). This showed that the test material at a nominal concentration of 10 mgC/l was not inhibitory to the degradation of the reference material sodium benzoate. In this preliminary test, Fannin DM08P was degraded to 1% of its Chemical Oxygen Demand (COD, 2.53 mgO:z/mg; Huntingdon Life Sciences Report No. 96/KAS 151/0311).

In the Modified Sturm Test, Farmin DM08P was added to two vessels containing mineral salts medium, activated sludge (30 mg solids/I; obtained from a domestic sewage ·works at Oakley, Suffolk) to give a nominal test concentration of 10 mgC/I. Control vessels comprised two containing inoculated mineral salts medium alone and one containing inoculated mineral salts medium plus sodium benzoate (10 mgC/I). Test and control vessels were aerated for 29 days with air that had been treated to remove CO2. The CO2 produced by each culture was trapped in a series of Drechsel bottles containing barium hydroxide which were connected to the outlet from each test vessel. The residual barium hydroxide was determined at intervals by titration.

Reference substance:

benzoic acid, sodium salt

Preliminary study:

A five-day bacterial inhibition test was performed under the conditions of the ClosedBottle Test (EC Procedure C.4-E, OECD Procedure 301D). This showed that the test material at a nominal concentration of 10 mgC/l was not inhibitory to the degradation of the reference material sodium benzoate. In this preliminary test, Fannin DM08P was degraded to 1% of its Chemical Oxygen Demand (COD, 2.53 mgO:z/mg; Huntingdon Life Sciences Report No. 96/KAS 151/0311).

Test performance:

Sodium benzoate was degraded by 60% after five days and 91% after 29 days. Cumulative C02 production in the controls after 29 days (91.6 and 90.6 mgCO2) was within the acceptable range for this assay system (recommended maximum = 120 mgC02 for a three litre culture).

Key result

Parameter:

% degradation (CO2 evolution)

Value:

15

Sampling time:

3 d

Key result

Parameter:

% degradation (CO2 evolution)

Value:

67

Sampling time:

7 d

Key result

Parameter:

% degradation (CO2 evolution)

Value:

98

Sampling time:

29 d

Details on results:

Mean cumulative CO2 production by the mixtures containing AD-1 at 10 mgC/l was equivalent to 15% of the theoretical value after three days and 67% after seven days; 98% degradation was achieved after 29 days.
Substances are considered to be readily degradable in this test if CO2 production is equal to or greater than 60% of the theoretical value within ten days of the level achieving 10%.
AD-1 can therefore be considered to be readily degradable.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The ready biodegradability of AD-1 was assessed in the carbon dioxide (CO2) Evolution Test (Modified Sturm Test, Procedure C.4-C of the Annex to Directive 92/69/EEC; OECD Procedure 301B).

Mean cumulative CO2 production by the mixtures containing AD-1 at 10 mgC/l was equivalent to 15% of the theoretical value after three days and 67% after seven days; 98% degradation was achieved after 29 days.
Substances are considered to be readily degradable in this test if CO2 production is equal to or greater than 60% of the theoretical value within ten days of the level achieving 10%.
AD-1 can therefore be considered to be readily degradable.

Executive summary:

The ready biodegradability of AD-1 was assessed in the carbon dioxide (CO2) Evolution Test (Modified Sturm Test, Procedure C.4-C of the Annex to Directive 92/69/EEC; OECD Procedure 301B).

Mean cumulative CO2 production by the mixtures containing AD-1 at 10 mgC/l was equivalent to 15% of the theoretical value after three days and 67% after seven days; 98% degradation was achieved after 29 days.

Substances are considered to be readily degradable in this test if CO2 production is equal to or greater than 60% of the theoretical value within ten days of the level achieving 10%.

AD-1 can therefore be considered to be readily degradable.

Description of key information

The ready biodegradability of AD-1 was assessed in the carbon dioxide (CO2) Evolution Test (Modified Sturm Test, Procedure C.4 -C of the Annex to Directive 92/69/EEC; OECD Procedure 301B).

Mean cumulative CO2 production by the mixtures containing AD-1 at 10 mgC/L was equivalent to 15% of the theoretical value after three days and 67% after seven days; 98% degradation was achieved after 29 days.

Substances are considered to be readily degradable in this test if CO2 production is equal to or greater than 60% of the theoretical value within ten days of the level achieving 10%.

AD-1 can therefore be considered to be readily degradable.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable