Registration Dossier

Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Study period:
8 April 1998
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Guideline compliant study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1998
Report Date:
1998

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
Deviations:
no
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): BEPD and BEDP
- Physical state: white solid
- Analytical purity: >99%
- Water solubility: 8 g/L at 20°C
- Volatility: <2.0 Pa at 20°C
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
Not applicable

Sampling and analysis

Analytical monitoring:
not required
Details on sampling:
Not applicable

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
activated sludge
Details on inoculum:
Obtained from Louddens municipal sewage plant, Stockholm, Sweden and sampled on April 8, 1998. The sludge contained 20 g dry matter/L after prescribed washing and centrifugation.

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
3 h
Post exposure observation period:
Not applicable

Test conditions

Hardness:
Not applicable
Test temperature:
Not reported
pH:
Not applicable
Dissolved oxygen:
Not reported
Salinity:
Not applicable
Nominal and measured concentrations:
concentration of BEPD used: 0 , 51.5, 103, 258, 515 and 2575 mg/L, calcuated from total organic carbon (TOC).
Reference substance (positive control):
yes
Remarks:
3,5-dichlorophenol

Results and discussion

Effect concentrationsopen allclose all
Duration:
3 h
Dose descriptor:
EC50
Effect conc.:
650 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Duration:
3 h
Dose descriptor:
other: EC20
Effect conc.:
50 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Duration:
3 h
Dose descriptor:
other: EC80
Effect conc.:
2 600 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Results with reference substance (positive control):
3,5-dichlorophenol was tested at 1, 5, 10 and 25 mg/L. Inhibition of respiration compared to the control after 3 hours was 27, 45, 62 and 86% at 1, 5, 10 and 25 mg/L.
Reported statistics and error estimates:
3 hour EC50 was determined from a plot (log normal).

Any other information on results incl. tables

Results of the definitive test

BEPD (mg/L) calculated from TOC

Inhibition of respiration related to control (%) 30 mins

Inhibition of respiration related to control (%) 3 hours

Reference 3,5-dichlorophenol (mg/L)

Inhibition of respiration related to control (%) 3 hours

0

0

0

0

0

0

0

51.5 (1%)

19

22

21

22

1

27

103 (2%)

25

28

26

28

5

45

258 (5%)

42

44

42

35

10

62

515 (10%)

42

48

46

49

25

86

2575 (25%)

79

76

80

82

 

 

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Remarks:
The EC50 for the reference inhibitor, 3,5-dichlorophenol was in the range of 5 - 30 mg/L.
Conclusions:
The 3-hour EC50 of BEPD based on suppression of the respiration of activated sludge microorganisms was 650 mg/L.
Executive summary:

Activated sludge obtained from a sewage treatment plant was exposed in a 3 -hour respiration inhibition test to concentrations of 0, 51.1, 103, 258, 515 and 2575 mg BEPD/L, nominal concentrations were calculated from TOC. The test design included duplicate samples and followed OECD 209 guidelines. The 3 -hour EC50 based on respiration inhibition was 650 mg BEPD/L.