Pentyl valerate

Biodegradation in water and sediment: simulation tests

Administrative data

Endpoint:

biodegradation in water: sewage treatment simulation testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2016-08-08 to 2016-09-07

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: OECD 301B

Deviations:

yes

Remarks:

uncritical (other slightly different temperature, but positive control showed normal degradation range)

GLP compliance:

yes (incl. QA statement)

Remarks:

certified by Landesamt für Umwelt, Wasserwirtschaft und Gewerbeaufsicht, Kaiser-Friedrich-Str. 7,D- 55116 Mainz, Germany

Test material

Test material information

Constituent 1

Reference substance name:

Pentyl valerate

EC Number:

218-528-7

EC Name:

Pentyl valerate

Cas Number:

2173-56-0

Molecular formula:

C10H20O2

IUPAC Name:

pentyl valerate

Test material form:

liquid

Radiolabelling:

no

Study design

Oxygen conditions:

aerobic

Remarks:

test vessels were aerated with purified, CO2-scrubbed, moistened air

Inoculum or test system:

other: Activated sludge from a biologic sewage treatment plant was used. The chosen plant is treating mostly domestic sewage.

Details on source and properties of sediment:

The sludge was taken from the activation basin of the ESN (Stadtentsorgung Neustadt, Im Altenschemel, NW-Lachen-Speyerdorf, mostly domestic sewage) sewage treatment plant, at August 5th, 2016. The sludge was filtrated, washed twice with tap water, washed with and resuspended in test medium and aerated until use. Dry matter: 3600mg suspended solids/L, microorganisms not specified

Details on inoculum:

Activated sludge was used as inoculum (concentration in the test 25.0 mg dry matter/L)

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

28.7 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

Sludge from an activation basin of a biological sewage treatment plant was given in a defined mineral medium under aerobic conditions in the dark. Then the test substance ( 29-30mg/L, ca. 20mg/L organic C), the positive control (anilline, 26.3mg/L, 20.0/L organic C) were added. The amount of emitted CO2 was trapped in 0.25 M NaOH and analysed on days 0,2,4,7,9,11,18,23 and 29 using a carbon analyser TOC multi N/C, Analytik Jena. On day 28 HCl was added to the test flasks to drive dissolved CO2 out. The content of CO2 was determined as sodium hydrogen carbonate and sodium carbonate (IC) the emitted carbon and degradation values were calculated. 2 flasks with test substance, 2 flasks with positive control, an abiotic control (with mercury chloride, kills all organisms), and a toxicity control (with both test substance and positive control) were measured in general.

Reference substance

Reference substance:

aniline

Results and discussion

% Degradation

Key result

% Degr.:

73

Parameter:

CO2 evolution

Sampling time:

28 d

Transformation products:

not measured

Details on results:

The following data were determined for the test item Pentyl valerate:
10-day-window: day 3 – 13
degradation at the end of 10-day-window 65 %
degradation at the end of the test 73 %

Results with reference substance:

Aniline (Phenylamine, C6H5NH2, CAS-No. 62-53-3) was used as readily biodegradable positive control.
Degradation of the positive control was 69 % after 9 days.

Applicant's summary and conclusion

Validity criteria

Validity criteria fulfilled:

yes

Remarks:

Both replicates showed good correspondence.

Conclusions:

The test substance is not toxic towards the inoculum (the microorganisms from the sludge) in a concentration of 30.9 mg/L.
Pentyl valerate is readily biodegradable following OECD 301B/EU C.4-C.