Registration Dossier

Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Comparable to guideline study with acceptable restrictions (e.g. non-GLP)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1992
Report Date:
1992

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
TS-Freetext:
2,6-Dimethylaniline

Sampling and analysis

Analytical monitoring:
no

Test organisms

Test organisms (species):
activated sludge, domestic
Details on inoculum:
- inoculum: activated sludge from laboratory wwtp treating domestic sewage

Study design

Test type:
static
Water media type:
freshwater
Total exposure duration:
30 min

Test conditions

Details on test conditions:
- activated sludge: 1 g/l dry matter
- test concentrations (mg/l): 55, 100, and 1000
- reference substance: 3.5-dichlorophenol (test concentrations: 1, 10 , and 100 mg/l)

Results and discussion

Effect concentrationsopen allclose all
Duration:
30 min
Dose descriptor:
other: EC20
Effect conc.:
ca. 150 mg/L
Nominal / measured:
nominal
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Duration:
30 min
Dose descriptor:
EC50
Effect conc.:
ca. 550 mg/L
Nominal / measured:
nominal
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate

Any other information on results incl. tables

RS-Freetext:
Effect values (30 min, mg/l):
EC20 ca. 150
EC50 ca. 550

reference substance:
EC20 ca. 3.5
EC50 ca. 20 (validity range: 5-30 mg/l)
EC80 > 100

Respiration inhibition after 30 min incubation period:

Test item Respiration Respiration
rate* inhibition
(mg/l) (mg O2/l*h) (%)
test substance:
55 15.5 14
100 13 28
1000 6 66

reference substance:
1 19.5 -8.3 promotion
10 10.5 42
100 5.5 69


* reference values for respiration rate: 16.5, 18.5 , and 18.5 mg/l*h


Highest tested concentration with less than 20 % respiration inhibition: 1950 mg/l

Applicant's summary and conclusion

Validity criteria fulfilled:
yes