Butanedioic acid, 2-hydroxy-, 1,4-bis[5,7,7-trimethyl-2-(1,3,3-trimethylbutyl)octyl] ester

Biodegradation in water: screening tests

Administrative data

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:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

1,4-bis[2-(4,4-dimethylpentan-2-yl)-5,7,7-trimethyloctyl] 2-hydroxybutanedioate

Cas Number:

66918-01-2

Molecular formula:

C40H78O5

IUPAC Name:

1,4-bis[2-(4,4-dimethylpentan-2-yl)-5,7,7-trimethyloctyl] 2-hydroxybutanedioate

Details on test material:

- Name of test material (as cited in study report): SALACOS 222
- Physical state: liquid
- Analytical purity: > 98%
- Lot/batch No.: 7-2-D
- Expiration date of the lot/batch: 04/10
- Stability under test conditions: stable under storage conditions
- Storage condition of test material: room temperature (20 +/- 0.5 °C), light protected

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 7-2-D
- Expiration date of the lot/batch: April 2010
- Purity test date: not stated

RADIOLABELLING INFORMATION (if applicable)
not applicable

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature, away from direct sunlight
- Stability under test conditions: assumed stable
- Solubility and stability of the test substance in the solvent/vehicle: assumed stable
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: assumed stable


TREATMENT OF TEST MATERIAL PRIOR TO TESTING
none

Study design

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):
- origin: wastewater treatment plant (ARA Ergholz II, Füllinsdorf; Switzerland)
- Preparation of inoculum for exposure: sludge was washed twice by centrifugation and the supernatant liquid phase was decanted
- Pretreatment: determination of ratio dry/wet weight; suspension in test water (conc. eq.: 4 g wet weight/L); holding for two days (aeration at room temp.); prior to use two-step dilution: 1 g wet weight/L, 30 mg wet weight/L
- Concentration of sludge: 30 mg dry weight/L

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: according to Guideline
- Additional substrate: none
- Solubilising agent (type and concentration if used):
- Test temperature: 22 °C
- pH: start: 7.5; end: 7.5-7.9
- pH adjusted: no
- CEC (meq/100 g):
- Aeration of dilution water:
- Suspended solids concentration:
- Continuous darkness: yes
- Other:

TEST SYSTEM
250 mL test solution per flask,
Due to the complex structure (composition) of the test item, its chemical oxygen demand (COD)
was determined according to theEU Commission Directive 92/69氾EC, C.6 following DIN
38414-S9.
The COD was detemined at BMG Engineering AG, Ifangstrasse 11, 8952 Schlieren I
Switzerland. The COD determination was not performed in compliance with the GLP regulations.


SAMPLING
- Sampling frequency: dayly
- Sampling method: cumulative oxygen consumption
- Sterility check if applicable: not stated
- Sample storage before analysis: not stated
- Other:

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Abiotic sterile control: none
- Toxicity control:yes
- Other:

STATISTICAL METHODS: none applied

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

Key result

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Details on results:

The percent biodegradationof the test item was calculated based on the chemical oxygen
demand (COD) of 1.34 mg O2/mg test item.
The biochemical oxygen demand (BOD) of the test item in the test media was in
the normal range found for the inoculum controls throughout the study period of 28 days.

BOD5 / COD results

BOD5 / COD

Key result

Parameter:

COD

Value:

1.34 mg O2/g test mat.

Results with reference substance:

reference item was degraded by an average of 83% by Exposure Day 14. At the end of the test (day 28), the reference item was degraded by an average of 85%.

Any other information on results incl. tables

Validity of the test:

the substance was tested in duplicate and differences in values for the test item are negligable.

Toxicity control replicate showed no toxicity.

The cumulative oxygen consumption of the reference item was > 60 mg/L at the end of 28 days. However, as the test item was not biodegradable, this constraint is assesseed uncritical for the result of the study.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The biodegradation of the test item was determined in an manometric respiratory test according to the OECD testing guideline 301F. Although the suitability of the used test system was shown in the reference test, no biodegradation of the test item was observed during the test period. Thus, the test item is considered to be not readily biodegradable under the given test conditions. The presented data should be assumed to be relevant, reliable and adequate for the purpose of a REACH registration.

Executive summary:

The test item was investigated for its ready biodegradability in a manometric

respirometry test over 28 days according to the EU Commission Directive 92/69 EEC, C.4 -D

(1992) and the OECD Guideline for Testing of Chemicals No. 301 F (1992).

The biochemical oxygen demand (BOD) of the test item in the test media was in

the normal range found for the inoculum controls.

Consequently, the test item was not biodegradable under the test conditions within 28 days.

In the toxicity control, containing both the test item and the reference item sodium benzoate,

the test item had no inhibitory effect on the activity of activated sludge microorganisms at the

tested concentration of 100 mg/L.

In the procedure controls, the reference item sodium benzoate was degraded by an average of

83% by Exposure Day 14, and reached an average biodegradation of 85% by the end of the test

(Day 28), thus confirming suitability of the activated sludge.