Octanoic acid, compound with dicyclohexylamine (1:1)

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

Study period:

1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))

Deviations:

not specified

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Duration of test (contact time):

14 d

Initial conc.:

100 mg/L

Based on:

not specified

Parameter followed for biodegradation estimation:

O2 consumption

Key result

Parameter:

% degradation (O2 consumption)

Value:

76.9

Sampling time:

14 d

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The biodegradation of DCHA was investigated in a Modified MITI Test similar to OECD guideline 301 C. After a period of 14 days 77 % biodegradation was observed. Threfore DCHA can be reagarded as readily biodegradable.

Executive summary:

The biodegradation of DCHA was investigated in a Modified MITI Test similar to OECD guideline 301 C. After a period of 14 days 77 % biodegradation was observed. Threfore DCHA can be reagarded as readily biodegradable.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

no data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

oxygen concentration in test bottles below 0.5 mg/L at test end

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

sewage, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): effluent of the sewage treatment plant Hochdahl, Germany
- Initial cell/biomass concentration: 10 E+03 to 10 E+04 cells/mL
- Water filtered: yes
- Type and size of filter used, if any:through a corase paper filter, the first 200 mL were discarded

Duration of test (contact time):

30 d

Initial conc.:

2 mg/L

Based on:

test mat.

Initial conc.:

5 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: deionised water was used for the test which is not in line with the guideline.
- Solubilising agent (type and concentration if used): Sodium hydroxide
- Test temperature: 19.9 - 20.1 °C
- pH: 7 - 8
- Aeration of dilution water: aerated until O2 saturation was 8-9 mg O2/L

TEST SYSTEM
- Culturing apparatus: completely filled closed bottles
- Number of culture flasks/concentration: not specified (two parallels were run)

SAMPLING
- Sampling frequency reported: after 5, 15 and 30 days, which is not in line with the guideline
CONTROL AND BLANK SYSTEM
- Inoculum blank: 4

Reference substance:

other: Dodecylsulfate

Parameter:

% degradation (O2 consumption)

Value:

105

Sampling time:

30 d

Remarks on result:

other: 2 mg/L

Parameter:

% degradation (O2 consumption)

Value:

> 72

Sampling time:

30 d

Remarks on result:

other: 5 mg/L

Details on results:

More then 72 % of the test substance was degraded whithin 30 days at a test concentration of 5 mg/L. Due to the good biodegradability the oxygen concentration in this test concentration remained inadequate so that the 72% should be regarded as a minimum value. At a test concentratios of 2 mg/L octanoic acid was completely degraded. 60% were reached within the given 10 day window as required. Thus, the test substance can be regarded as readily biodegradable.

Parameter:

COD

Value:

2.51 mg O2/g test mat.

Results with reference substance:

The reference substance is readily biodegradable since 90 % was degraded after 30 days and over 60 % in the 10 day window. The ThOD of the reference substance was 2.02 mg O2/ mg dodecylsulfate

Interpretation of results:

readily biodegradable

Conclusions:

The ultimate biodegradability of "Edenor C8 98-100" (octanoic acid) was tested in the Closed Bottle Test (OECD 30ID). Under the chosen conditions > 72 % of the test substance was degraded within the 30 day test period. The pass level (= 60% ThOD for respirometric methods according to the OECD-Guideline 301) was reached within the 10-day time window and in conformity with the evaluation criteria. Octanoic acid can be regarded as readily biodegradable.

Executive summary:

The ultimate biodegradability of "Edenor C8 98-100" (octanoic acid) was tested in the Closed Bottle Test (OECD 30ID). Under the chosen conditions > 72 % of the test substance was degraded within the 30 day test period. The pass level (= 60% ThOD for respirometric methods according to the OECD-Guideline 301) was reached within the 10-day time window and in conformity with the evaluation criteria. Octanoic acid can be regarded as readily biodegradable.

Description of key information

In aqueous systems Octanoic acid, compound with dicyclohexylamine (1:1) will rapidly dissociate to octanoic acid and dicyclohexylamine. Both dissociation products are readily biodegradable. Therefore

Octanoic acid, compound with dicyclohexylamine (1:1) can be regarded as readily biodegradable.

DCHA:

The biodegradation of DCHA was investigated in a Modified MITI Test similar to OECD guideline 301 C. After a period of 14 days 77 % biodegradation was observed. Threfore DCHA can be reagarded as readily biodegradable.

Octanoic acid:

The ultimate biodegradability of "Edenor C8 98-100" (octanoic acid) was tested in the Closed Bottle Test (OECD 30ID). Under the chosen conditions > 72 % of the test substance was degraded within the 30 day test period. The pass level (= 60% ThOD for respirometric methods according to the OECD-Guideline 301) was reached within the 10-day time window and in conformity with the evaluation criteria. Octanoic acid can be regarded as readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

Read Across justification:

In aqueous systems Octanoic acid, compound with dicyclohexylamine (1:1) is hydrolytically very unstable so that in aqueous solution a rapid decomposition to the educts can be observed. The substance will rapidly dissociate to octanoic acid and dicyclohexylamine. Therefore Octanoic acid, compound with dicyclohexylamine (1:1) is not stable at “standard” testing conditions representative for human and environmental exposure. Hence, it is fully justified to apply the read-across methodology by use of the respective data from the breakdown/decomposition products to describe the (eco)toxicological behaviour of the substance to be registered.

Therefore Octanoic acid, compound with dicyclohexylamine (1:1) can be regarded as readily biodegradable.