Methyl crotonate

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

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

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH

The registration substance consist of the relevant structural elements short chain unsaturated aliphatic and carboxylic ester.
The analogues acrylic acid methyl ester and Ethylhexyl hydrogen maleate have the same structural elements.
Therefore it is considered, that the biodegradation properties of the registration substance are fully comparable to the analogues.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)

See test material in this endpont (source) and target chemicals studies.

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

read-across source

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 310 (Ready Biodegradability - CO2 in Sealed Vessels (Headspace Test)

GLP compliance:

yes

Inoculum or test system:

activated sludge, domestic, non-adapted

Parameter:

other: TIC/ThIC

Value:

99 - 100

Sampling time:

28 d

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Cross-reference 2

Reason / purpose for cross-reference:

read-across source

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: EEC Directive 79-831, Annex V, Part C: Methods for the Determination of Ecotoxicology; Degradation - Biotic Degradation; Manometric Respirometry.

Version / remarks:

Bruessel 1984

Qualifier:

equivalent or similar to guideline

Guideline:

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

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: Activated sludge from a laboratory wastewater treatment plant, which is operated with municipal wastewater.
- Concentration of the suspended substances at the beginning of the test: 30 mg/L

Duration of test (contact time):

28 d

Initial conc.:

103 mg/L

Based on:

test mat.

Initial conc.:

632 mg/L

Based on:

TOC

Details on study design:

TEST SYSTEM
- Culturing apparatus: Sapromat with 7 parallel test tubes. Test volume 2015 mL

CONTROL AND BLANK SYSTEM
- Inoculum blank: Yes, containing only inoculum
- Procedure control: Yes, containing reference compound and inoculum
- Abiotic sterile control: Yes, containing test substance and sterilising agent (HgCl2)
- Toxicity control: Yes, containing test substance, reference compound and inoculum

Reference substance:

aniline

Test performance:

In the respirometric test, the biodegradability of an organic substance in a static, aqueous system with activated sludge of a municipal sewage treatment plant as an inoculum is tested. The biochemical oxygen demand (BOD) in the respirometer is measured and compared with the theoretical oxygen demand (ThOD) and the measured chemical oxygen demand (COD) of the test substance.

Key result

Parameter:

other: % degradation (ThOD)

Value:

> 60

Sampling time:

28 d

Remarks on result:

other: BOD/ThOD (%) = 70%; BSB/CSB (%) = 65%

Details on results:

- Mean duration of lag-phase: 5 days
- Mean duration of degradation phase: 18 days

Results with reference substance:

- BOD*100 /THOD= 62 %

Interpretation of results:

readily biodegradable

Conclusions:

Under the conditions of this test the test substance is readily biodegradable as the pass level of >60% degradation was reached within the 28 days period of the study.

Executive summary:

The ready biodegradability of the test item was assessed over a 28 day period in a study equivalent to OECD guideline 301 C (BASF, 1989). The test item was tested at a concentration of 103 mg/L, corresponding to total organic carbon (TOC) of 632 mg/g. The test item was exposed to an aqueous system of activated sludge of a municipal sewage treatment plant as an inoculum for 28 days. The biodegradation was followed by the oxygen uptake (biological oxygen demand, BOD) during exposure. Aniline was tested as a reference substance and showed a degradation of 62% after 28 days. Under the conditions of this test the test substance is readily biodegradable as the pass level of >60% degradation was reached within the 28 days period of the study.

10 -day-window: yes