Fatty acids, coco, iso-Bu esters

Hydrolysis

Administrative data

Endpoint:

hydrolysis

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance is readily biodegradable

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

The biodegradability in water of the source substance has been investigated with an experimental study according to test method OECD 301 F.The source substance was found being readily biodegradable.

The same behaviour is predicted for the target substance.

Biodegradation in water:

readily biodegradable

Type of water:

freshwater

Cross-reference 2

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

28 Jan - 25 Feb 1999

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

sewage, predominantly domestic (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge: Sewage effluent was obtained from the waste water treatment plant Hochdahl, Germany, treating predominantly domestic sewage.

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

COD

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Amendment of test item: The solid test item was minced in a mortar and directly added to the test system.
- Amount of inoculum: 100 mL/L test medium

TEST SYSTEM
- Culturing apparatus: test flasks
- Number of culture flasks/concentration: 3

SAMPLING
- Sampling frequency: daily sampling and measurement


CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Reference control: yes, 3 flasks

Reference substance:

acetic acid, sodium salt

Parameter:

% degradation (O2 consumption)

Value:

18

Sampling time:

3 d

Parameter:

% degradation (O2 consumption)

Value:

69

Sampling time:

13 d

Parameter:

% degradation (O2 consumption)

Value:

87

Sampling time:

28 d

Details on results:

The test substance attained 69% degradation at the end of the 10-day window and 87% after 28 days.

Results with reference substance:

The reference substance attained 84% degradation after 14 days and 90% degradation after 28 days.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Cross-reference 3

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The target substance FATTY ACIDS, COCO, ISO-BU ESTERS (CAS 91697-43-7) and the source substance FATTY ACIDS, C16-18, ISOBUTYL ESTERS (CAS 85865-69-6) are both Short Chain Alcohol Esters (SCAE C2-C8) composed by a fatty acid (C16-C18) and a C4 alcohol (isobutanol).
The source and the target substance show therefore the same reactive groups and a similar composition. A read-across to the source is therefore justified.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
Both target and source substances are fatty acid esters produced by chemical reaction of an alcohol (isobutanol) with organic acids (e. g. stearic acid) in the presence of an acid catalyst. The esterification reaction is started by a transfer of a proton from the acid catalyst to the acid to form an alkyloxonium ion. The carboxylic acid is protonated on its carbonyl oxygen followed by a nucleophilic addition of a molecule of the alcohol to a carbonyl carbon of acid. An intermediate product is formed. This intermediate product loses a water molecule and proton to give an ester. Monoesters are the final product of esterification.

3. ANALOGUE APPROACH JUSTIFICATION
Since both target and source substances are fatty acid esters produced by chemical reaction of an alcohol (isobutanol) with an organic acid and therefore share similar/overlapping structural features and functional groups, it is justified to use a read across approach. The source substance has been registered already and its biodegradability in water has been investigated with an experimental study according to test method OECD 301 F.The source substance was found being readily biodegradable.
The same behaviour is predicted for the target substance.

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Parameter:

% degradation (O2 consumption)

Value:

18

Sampling time:

3 d

Parameter:

% degradation (O2 consumption)

Value:

69

Sampling time:

13 d

Parameter:

% degradation (O2 consumption)

Value:

87

Sampling time:

28 d

Details on results:

The test substance attained 69% degradation at the end of the 10-day window and 87% after 28 days

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The biodegradability in water of the source substance has been investigated with an experimental study according to test method OECD 301 F.The source substance was found being readily biodegradable.
The same behaviour is predicted for the target substance.

Executive summary:

The target substance FATTY ACIDS, COCO, ISO-BU ESTERS (CAS 91697-43-7) and the source substance FATTY ACIDS, C16-18, ISOBUTYL ESTERS (CAS 85865-69-6) are both Short Chain Alcohol Esters (SCAE C2-C8) composed by a fatty acid (C16-C18) and a C4 alcohol (isobutanol).

The source and the target substance show therefore the same reactive groups and a similar composition. A read-across to the source is therefore justified.

The source substance has been registered already and its biodegradability in water has been investigated with an experimental study according to test method OECD 301 F.The source substance was found being readily biodegradable.

The same behaviour is predicted for the target substance.