Dichloromethylbenzene

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1991

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

deviations from the current OECD-guideline were not reported, but validity criteria may be assessed only partially

Justification for type of information:

GLP-study, deviations from the current OECD-guideline were not reported, but validity criteria may be assessed only partially

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Deviations:

not specified

GLP compliance:

yes

Specific details on test material used for the study:

Not applicable

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): laboratory sewage treatment plant, conducted with domestic effluent
- Initial cell/biomass concentration: 0.03 g dry weight /L

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

not specified

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

Details not provided

Reference substance:

aniline

Preliminary study:

Details not provided

Test performance:

Details not provided

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Details on results:

Please refer to table presented in the field "Overall remarks"

Results with reference substance:

The reference substance degraded to 94% within the test period of 28 days.

Theoretical oxygen demand: 1590 mg O2/g.

Results

Time [d]	O2-consumption test substance [mg/L]	O2-consumption Inoculum blank [mg/L]	Degradation rate   [%]
2	3	3	0
4	-	-	-
6	4	6	0
8	-	-	-
10	5	7	0
12	-	-	-
14	5	7	0
16	5	7	0
18	-	-	-
20	5	7	0
22	5	7	0
24	5	7	0
26	-	-	-
28	5	7	0

Validity criteria fulfilled:

yes

Remarks:

Oxygen consumption of inoculum blank < 60 g/L; others were not reported

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

0% degradation odf dichloromethylbenzene was observed within 28 days.

Executive summary:

A 28-d Manometric Respirometry Test was performed with dichloromethylbenzene mixture according to the OECD Guideline 301F. Test substance concentration was 100 mg/L.

0% degradation was observed within 28 days.

Dichloromethylbenzene mixture is not readily biodegradable.

Reference: Caspers & Müller, 1991

Description of key information

The ready biodegradability of dichloromethylbenzene mixture was tested in a 28-d Manometric Respirometry Test according to the OECD Guideline 301F. 0% degradation was observed within 28 days.
Dichloromethylbenzene mixture is not readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

Key study

 

A 28-d Manometric Respirometry Test was performed with dichloromethylbenzene mixture according to the OECD Guideline 301F. Test substance concentration was 100 mg/L. 0% degradation was observed within 28 days.

Dichloromethylbenzene mixture is not readily biodegradable.

Reference: Caspers & Müller, 1991

 

Supporting study

 

A 28-d Modified MITI Test was performed with 2,4-dichlorotoluene according to the OECD Guideline 301C. Test substance concentration was 100 mg/L. 0% degradation was observed within 28 days.

2,4-dichlorotoluene is not readily biodegradable.

Reference: MITI, 1993

Further studies

 

A 28-d Closed Bottle Test was performed with 3,4-dichlorotoluene according to the OECD Guideline 301D. Test substance concentration was 4.17 mg/L. 0% degradation was observed within 28 days.

3,4-dichlorotoluene is not readily biodegradable.

As only a short abstract is available, the reliability cannot be assessed.

Reference: NITE database, 2002

 

A 30-d Manometric Respirometry Test was performed with a dichlorotoluene mixture containing more 2,6-dichlorotoluene according to the EU Guideline C.5.2 and to GLP. Test substance concentration was 100 mg/L. 0% degradation was observed within 30 days.

The tested dichlorotoluene mixture is not readily biodegradable.

As only a short abstract is available, the reliability cannot be assessed.

Reference: FhG, 1989

  

A 20-d Closed bottle test was performed with another similar dichloromethylbenzene mixture. Test substance concentrations were 2.4, 8, 24 and 80 mg/L.

0 % biodegradation was observed.

As only a a short abstract is available, the reliability cannot be assessed.

Reference: Bayer, 1983

 

A 20-d biodegradation test (not further specified) was performed with the isomer 2,4-dichlorotoluene. Test substance concentrations were 2.4 - 80 mg/L. 0% degradation was observed. Reliability 3 due to the use of adapted sludge.

Reference: Verschueren, >= 1996

 

An incomplete entry in IUCLID4 on a BOD5 -determination with a mixture of 2,6- 2,4- and 2,5 -dichlorotoluene (containing more 2,6-dichlorotoluene compared with the mixture, which is described in this dossier): ThOD = 1590 mg/g. Results for BOD5 and COD are not reported.

Reliability 3 due to missing results.

Reference FhG, 1989