3-chlorobutan-2-one

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:

2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: OECD Guideline Study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

3-chlorobutan-2-one

EC Number:

223-834-9

EC Name:

3-chlorobutan-2-one

Cas Number:

4091-39-8

Molecular formula:

C4H7ClO

IUPAC Name:

3-chlorobutan-2-one

Constituent 2

Reference substance name:

3-Chloro-2-butanone

IUPAC Name:

3-Chloro-2-butanone

Test material form:

other: colourless liquid

Details on test material:

Purity > 98% (GC).

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

Inoculation was made using a secondary effluent of good quality collected from a
treatment plant dealing with predominantly domestic sewage. The effluent was kept
under aerobic conditions in the period between sampling and application. To prepare
the inoculum the sample was filtered through a coarse filter, the first 200 mL being
discarded. The rest of the filtrate was kept aerobic until use. The inoculum was used
on the day of collection. The number of bacteria was determined with Easicult TTC.
There were 10exp8 bacteria per litre of final volume of the test medium.

Duration of test (contact time):

ca. 28 d

Initial test substance concentration

Initial conc.:

ca. 2 mg/L

Reference substance

Reference substance:

acetic acid, sodium salt

Results and discussion

% Degradation

Parameter:

% degradation (O2 consumption)

Value:

ca. 71

Sampling time:

28 d

BOD5 / COD results

Results with reference substance:

The reference compound sodium acetate was biodegraded by an average of 67.5 %
by exposure day 14 and reached an average biodegradation rate of 66.0% by the
end of the 28-day exposure period.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

3-Chlorbutanon-2 was degraded (71.6%) during the test period. Since 74.9%
biodegradation was reached within ten days of biodegradation, the criterion for ready
biodegradability was met. Thus, under the conditions of this test 3-Chlorbutanon-2
was readily biodegradable.

Executive summary:

Under the present test conditions, 3-Chlorbutanon-2 was readily biodegraded by an

average of 71.6% over the 28-day exposure period to a secondary effluent from a

domestic sewage treatment plant.

The criterion for ready biodegradability (at least 60% biodegradation was reached

within ten days of biodegradation exceeding 10%) was met.

On the other hand, the reference compound sodium acetate was biodegraded by an

average of 67.5 % by exposure day 14 and reached an average biodegradation rate

of 66.0% by the end of the 28-day exposure period, thus confirming suitability of

the secondary effluent.

The test substance did not inhibit the inoculum in the toxicity control.

In conclusion, 3-Chlorbutanon-2 was readily biodegradable under the conditions of

the' Closed Bottle Test'.