Registration Dossier

Environmental fate & pathways

Biodegradation in water: screening tests

Administrative data

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study was conducted according GLP and internationally recognized test guidelines. Scored as Reliability level 2 as per ECHA guidance for studies used for read-across endpoints.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2013
Report Date:
2013

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
Qualifier:
according to
Guideline:
EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)
Qualifier:
according to
Guideline:
ISO DIS 9439 (Ultimate Aerobic Biodegradability - Method by Analysis of Released Carbon Dioxide)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder
Details on test material:
Molecular formula: C23H35NO2
Molecular weight: 357.53
CAS Number: 159325-45-8
Description: Cream powder with lumps (determined at WIL Research Europe B.V.)
Batch: DGJ524K1NAT
Purity/Composition: 85-95%
Test substance storage: At room temperature in the dark
Stability under storage conditions: Stable

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic (adaptation not specified)
Details on inoculum:
Source: The source of test organisms was activated sludge freshly obtained from a municipal sewage treatment plant: 'Waterschap Aa en Maas', Heeswijk-Dinther, The Netherlands, receiving predominantly domestic sewage.
Treatment: The freshly obtained sludge was used immediately. The concentration of suspended solids was 5.0 g/l in the concentrated sludge (information obtained from the municipal sewage treatment plant). Before use, the sludge was allowed to settle (53 minutes) and the supernatant liquid was used as inoculum at the amount of 10 ml/l of mineral medium.
Reason for selection: The test has been accepted internationally for determining the 'ready' biodegradability of test substances under aerobic conditions.
Duration of test (contact time):
28 d
Initial test substance concentration
Initial conc.:
16 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
CO2 evolution
Details on study design:
Test duration: 28 days (last CO2-measurement on the 29th day). During the test period the test media were aerated and stirred continuously.
Test vessels: 2 litre all-glass brown coloured bottles.
Milli-RO / Milli-Q water: Tap-water purified by reverse osmosis (Milli-RO) and subsequently passed over activated carbon and ion-exchange cartridges (Milli-Q) (Millipore Corp., Bedford, Mass., USA).
Stock solutions of mineral components: A) 8.50 g KH2PO4, 21.75 g K2HPO4, 67.20 g Na2HPO4.12H2O, 0.50 g NH4Cl, dissolved in Milli-Q water and made up to 1 litre, pH 7.4 ± 0.2. B) 22.50 g MgSO4.7H2O dissolved in Milli-Q water and made up to 1 litre. C) 36.40 g CaCl2.2H2O dissolved in Milli-Q water and made up to 1 litre. D) 0.25 g FeCl3.6H2O dissolved in Milli-Q water and made up to 1 litre.
Mineral medium: 1 litre mineral medium contains: 10 ml of solution (A), 1 ml of solutions (B) to (D) and Milli-RO water.
Barium hydroxide: 0.0125 M Ba(OH)2 (Boom, The Netherlands), stored in a sealed vessel to prevent absorption of CO2 from the air.
Synthetic air (CO2 < 1 ppm): A mixture of oxygen (ca. 20%) and nitrogen (ca. 80%) was passed through a bottle, containing 0.5 - 1 litre 0.0125 M Ba(OH)2 solution to trap CO2 which might be present in small amounts. The synthetic air was sparged through the scrubbing solutions at a rate of approximately 1-2 bubbles per second (ca. 30-100 ml/min).
Reference substance
Reference substance:
acetic acid, sodium salt

Results and discussion

Test performance:
The relative biodegradation values calculated from the measurements performed during the test period revealed 92% and 77% biodegradation of EPYRRON-OPL, for A and B, respectively. Furthermore, biodegradation of EPYRRON-OPL of at least 60% was reached within a 10-day window in test bottle A. In the toxicity control more than 25% biodegradation occurred within 14 days (47%, based on ThCO2). Therefore, the test substance was assumed not to inhibit microbial activity.
% Degradation
Parameter:
% degradation (CO2 evolution)
Value:
>= 77 - <= 92
Sampling time:
28 d
Details on results:
The relative biodegradation values calculated from the measurements performed during the test period revealed 92% and 77% biodegradation of EPYRRON-OPL, for A and B, respectively. Furthermore, biodegradation of EPYRRON-OPL of at least 60% was reached within a 10-day window in test bottle A.

BOD5 / COD results

Results with reference substance:
Functioning of the test system was checked by testing the reference substance sodium acetate, which showed a normal biodegradation curve.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable
Conclusions:
Epyrron-OPL was readily biodegradable under the conditions of the modified Sturm test presently performed and by read across Epyrrol is considered to be also readily biodegradable.
Executive summary:

EpyrronOPL was readily biodegradable under the conditions of the modified Sturm test presently performed and by read across Epyrrol is considered to be also readily biodegradable.