Ethanol, 1-[2-butyne-1,4-diylbis(oxy)][2,2,2-trichloro-

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Remarks:

potential deviations would be documented in amendments

GLP compliance:

yes (incl. QA statement)

Remarks:

GLP-Conformity All procedures according to the principles of GLP (Chemikaliengesetz §19a and §19b and annexes 1 and 2 from 28. Aug. 2013, published in Federal Law Gazette, Germany (BGBl) No. 55/2013 as of 06. Sep. 2013, and further revisions).

Test material

Test material information

Constituent 1

Test material form:

liquid

Details on test material:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: The test material is representative of the registered substance, and no significant differences in the purity profile exist
- Expiration date of the lot/batch: not relevant (stable)
- Purity test date: not relevant, the test material is representative of the registered substance

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: at room temperature in the dark
- Stability under test conditions: stable
- Solubility and stability of the test substance in the solvent/vehicle: soluble
- Reactivity of the test substance with the solvent: none (contains water)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: The test material is representative of the registered substance
- Expiration date of the lot/batch: not relevant
- Purity test date: not relevant

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: at room temperature in the dark
- Stability under test conditions: stable
- Solubility and stability of the test substance in the solvent/vehicle: soluble

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: none
- Preliminary purification step (if any): none

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Activated sludge from a biologic sewage treatment plant was used as inoculum. The chosen plant is treating mostly domestic sewage.
The sludge was collected from the activation basin of the sewage treatment plant Edenkoben on 23. Feb. 2018, batch no: 20180223.
The sludge was filtrated, washed with test medium (2x) and re-suspended in test medium. It was then aerated until use. The dry matter was determined to contain 3980 mg of sus-pended solids/L.

Duration of test (contact time):

28 d

Details on study design:

This study performed in order to evaluate ready aerobic degradation of test item by aerobe microorganisms at a given concentration.
A solution, or suspension, of the test item in a mineral medium is inoculated and incubated under aerobic conditions in the dark. The amount of organic carbon in the test solution due to the inoculum is kept as low as possible compared with the amount of organic carbon due to the test item. Allowance is made for the endogenous activity of the inoculum by running parallel blanks with inoculum but without test item. A positive control is run in parallel to check the operation of the procedures. Degradation is followed by determining the amount of produced carbon dioxide. Measurements are taken at sufficiently frequent intervals to allow the identification of the beginning and end of biodegradation.
The test lasts for 28 days.

Test performance
The test vessels are aerated with purified (by activated charcoal), CO2-scrubbed, moistened air. The scrubbing of carbon dioxide is achieved by bubbling the purified air through a flask containing 1.5 M NaOH. To control the absence of CO2, the air is led through a flask containing a solution of Ba(OH)2 before reaching the test vessels.
Magnetic stirrers are used to prevent deposition of inoculum.
The emitted CO2 is trapped in 0.25 M NaOH. Two scrubbers containing 100 mL each are connected in series to the test vessels.

Instruments and Devices
The following instruments and devices will be used. Specification will be given in the final report.
• Data logger for temperature
• Analytical scales
• Adjustable pipettes with one-way tips
• Carbon analyser
• pH-meter
• Heating chamber
• Standard laboratory equipment
Usage and, if applicable, calibration of all instruments following the corresponding SOP in the current edition.

Reference substance

Reference substance:

aniline

Remarks:

positive control

Results and discussion

% Degradation

Key result

Parameter:

% degradation (CO2 evolution)

Value:

ca. 70

Sampling time:

28 d

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

the substance is readily biodegradable

Executive summary:

The aerobic ready biodegradability of the test item was determined in the CO2 Evolution Test following OECD 301B resp. EU C.4-C. In very dilute domestic sludge, the test item was degraded 58 % after the 10-d-window and 70 % after 28 d at the end of the test. Taking the chemical properties of the test item into account the 10-day-window is disregarded, and as degradation surpassed 60 % in the course of the test, the substance is considered as readily biodegradable.