3'H-Cyclopropa[1,2]pregna-1,4,6-triene-3,20-dione, 1,2-dihydro-17-hydroxy-, (1.alpha.,2.alpha.)-

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:

Jun - Jul 1997

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1998

Report date:

1998

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

17-Hydroxy-1 alpha,2 alpha-methylene-4,6-pregnadiene-3,20-dione

EC Number:

606-682-1

Cas Number:

2098-65-9

Molecular formula:

C22 H28 O3

IUPAC Name:

17-Hydroxy-1 alpha,2 alpha-methylene-4,6-pregnadiene-3,20-dione

Test material form:

solid: bulk

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): municipal sewage treatment plant ("Kläranlage Berlin-Ruhleben")
- Preparation of inoculum for exposure: stirred and aerated

Duration of test (contact time):

30 d

Initial test substance concentration

Initial conc.:

10 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
The test substance ZK 12126 was incubated in a concentration of 10 mg carbon/L in triplicate. Additionally, a reference substance (sodium acetate) was tested in a single set according to the same pracedure, in order to verify the viability and activity of the degrading micraorganisms. One further set was incubated with sodium acetate as 10 mg carbon/I (reference substance) plus ZK 12126 as 10 mg carbon/L representing a toxicity contra
- Test temperature: 20-24 °C
- pH: 7.8-8.0
- pH adjusted: no
- Sampling days: 3, 4, 7, 9, 11, 14, 18, 23, 28, 30
- Details of trap for CO2 and volatile organics if used: For the determination of the C02 produced, three C02-absorber bottles, filled with 100 mL 0.025 N Ba(OH)2 each, were connected in se ries to the exit air-pipe of each test bottle. The amount of CO2 produced was determined by titration of the remaining Ba(OH)2 with 0.05 N standardised HCI. On days 3, 4, 7, 9, 11, 14, 18, 23, 28 and 30 the CO2-absorber bottle nearest to the test bottles was removed for the titration. The remaining two absorbers were each moved one pi ace closer to the test vessel and a new absorber bottle filled with fresh Ba(OH)2 was placed at the far end of the series.

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes, 3 replicates
- Abiotic sterile control: no
- Toxicity control: yes, 1 replicate
- Reference substance: yes, 1 replicate

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

Key result

Parameter:

% degradation (CO2 evolution)

Value:

2

Sampling time:

28 d

BOD5 / COD results

Results with reference substance:

The reference compound sodium acetate produced 105 mg CO2, which was equivalent to 96% of the theoretical CO2 production after 28 d

Any other information on results incl. tables

Table 1: Biological degradation (cumulative) in percent (corrected for blank CO2-production) of 1,2-Methylen-4,6-Dien

 

Test	Nominal	Day of sampling
compound	concentration	3	4	7	9	11	14	18	23	28	30
	of carbon
ZK 12126	10 mg/I	1	0	0	1	0	0	2	1	2	2
Sodium acetate	10 mg/I	14	27	58	67	74	82	88	92	93	96
(reference)
ZK 12126 +	10 mg/I +	6	13	29	34	37	41	43	45	45	46
sodium acetate (toxicity control)	10 mg/I

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

In accordance with the OECD guideline, the test compound 1,2 Methylen-4,6-dien is not readily biodegradable under the conditions of the test and it was not toxic to the microbes of activated sludge.

Executive summary:

The purpose of this study was to determine the ready biodegradability of 1,2 Methylen-4,6-dien. The study was conducted in agreement with the following test guideline: OECD guideline for testing of chemicals, ready biodegradability: CO2-evolution test, no. 301 B, adopted Jul. 92, OECD Paris, 93.

The test substance was incubated in an aqueous solution including nutrients with micraorganisms fram a municipal sewage treatment plant for 28 days (start of treatment = day 1). The nutrient solutions were made up of phosphates, ammonium sulphate, magnesium sulphate, iran chloride, ammonium chloride and calcium chloride. The test substance was incubated in a concentration of 10 mg carbon/L in triplicate. Additionally, a reference substance (sodium acetate) was tested in a single set according to the same pracedure, in order to verify the viability and activity of the degrading micraorganisms. One further set was incubated with sodium acetate as 10 mg carbon/L (reference substance) plus test substance as 10 mg carbon/L representing a toxicity control. Furthermore, a blank control was tested in triplicate without any test or reference substance. The biological degradation of the test and reference substances was evaluated by measurement of the carbon dioxide (CO2) produced during the test period.

The test compound was practically not degraded on day 30 (28 days of incubation). The reference compound sodium acetate was degraded to 96% on day 30. The time required for 60% biodegradation of the reference compound was less than 10 days. In the toxicity control, the reference compound (sodium acetate) plus the test compound was degraded up to 46% on day 30, thus reflecting the degradation of the substances incubated separately.