1,2-dichloropropane

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:

04 February - 04 March, 2011

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2011

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPPTS 835.3110 (Ready Biodegradability)

Test guideline 3

Qualifier:

according to guideline

Guideline:

EU Method C.4-E (Determination of the "Ready" Biodegradability - Closed Bottle Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

1,2-dichloropropane

EC Number:

201-152-2

EC Name:

1,2-dichloropropane

Cas Number:

78-87-5

Molecular formula:

C3H6Cl2

IUPAC Name:

1,2-dichloropropane

Details on test material:

Name: 1,2-dichloropropane
Purity: 99.69 % w/w
Description: clear liquid
Storage: room temperature

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

The activated sludge used for this study was washed by centrifugation (for 10 min.) and the supernatant liquid phase was decanted. The solid material was re-suspended in isotonic saline solution and again centrifuged (for 10 min.). This procedure was repeated twice. An aliquot of the final sludge suspension was weighed, dried and the ratio of wet sludge to its dry weight was determined. Based on this ratio, calculated aliquots of washed sludge suspension, corresponding to 4 g dry material per litre were mixed with test water and then aerated until use. Before use the sludge was filtered through cotton wool.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

5.3 mg/L

Based on:

test mat.

Reference substance

Reference substance:

other: Sodium benzoate

Results and discussion

% Degradation

Parameter:

other: ThODNH4

Value:

11.7

Sampling time:

28 d

Remarks on result:

other: St. dev no data

Details on results:

Treatment Concentration Flask Percent of biodegradation after n days of exposure
[mg/L] No. 7 14 21 28
Test item 1a 2.5 5.8 9.2 11.7
5.3 1b 2.5 2.5 7.5 11.7
mean 2.5 4.2 8.3 11.7
Reference item 2a 79.2 82.5 87.5 90.0
3.6 2b 75.8 84.2 85.8 90.0
mean 77.5 83.3 86.7 90.0
Toxicity control Test item: 5.3
Reference item: 3.6 4a 39.7 40.5 41.3 43.3
4b 38.9 39.7 42.9 44.1
mean 39.3 40.1 42.1 43.7

Any other information on results incl. tables

Under the test conditions the percentage biodegradation of1,2 - Dichloropropanereached a mean of 11.7 % after 28 days based on its ThOD_NH4.

The test item can therefore be considered to be not ready biodegradable.According to the test guidelines the pass level for ready biodegradability is removal of 60 % ThOD.

 

The reference item Sodium benzoate was sufficiently degraded to a mean of 83.3 % after 14 days, and to a mean of 90.0 % after 28 days of incubation, based on ThOD_NH4, thus confirming the suitability of the used activated sludge inoculum.

 

In the toxicity control containing both, the test item and the reference item Sodium benzoate, a mean of 40.1 % biodegradation was noted within 14 days and 43.7 % biodegradation after 28 days of incubation.

Applicant's summary and conclusion

Interpretation of results:

other: not ready biodegradable

Conclusions:

The test item can therefore be considered to be not ready biodegradable. According to the test guidelines the pass level for ready biodegradability is removal of 60 % ThOD.
According to the test guidelines the test item can be assumed to be not inhibitory at the applied concentration level of 5.3 mg/L on the activated sludge microorganisms because degradation was >25 % within 14 days.