Registration Dossier

Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2008-2009
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP compliant study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2009
Report Date:
2009

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Remarks:
migrated information: particulates
Details on test material:
test was performed with the tosylate salt of BAY 43-9006 (sorafenib tosylate=4-{4-[3-(4-Chloro-3-trifluoromethyl-phenyl)ureido]phenoxy}pyridine 2-carboxylic acid methylamide 4-methylbenzenesulfonate)

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
activated sludge of a predominantly domestic sewage

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
30 min

Results and discussion

Effect concentrations
Duration:
30 min
Dose descriptor:
NOEC
Effect conc.:
>= 32 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate

Any other information on results incl. tables

The respiration rate in the test vessels was not relevantly inhibited. There was no concentration

related effect. The NOEC was higher than the test range. The test material has a very low solubility, therefore, the activbated sludge was exposed to a saturated solution of the test material.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
Sorafenibtosylate had no concentration-depended inhibitory effect on the respiration rate of
activated sludge in the tested range
Executive summary:

The test substance sorafenibtosylate was incubated in aerated activated sludge with

microorganisms from a municipal sewage treatment plant including synthetic sewage feed for

approximately 30 min followed by the measurement of the respiration rate by an oxygen probe.

The synthetic sewage feed solution was made up of mainly peptone, meat extract and urea.

Sorafenibtosylate is only slightly soluble, therefore the test substance was directly introduced

into the test vessel. The amount was 0.5, 1, 2, 4 and 8 mg substance in 42 mL water,

ultrasonified for approximately 30 minutes and constantly stirred for approximately 30 minutes.

Subsequently, the inoculum and synthetic feed was added to each vessel. The resulting nominal

concentrations were 2, 4, 8, 16 and 32 mg/L. Additionally, a reference substance

(3,5-dichlorophenole) in three concentrations (5, 15 and 30 mg/L in test vessel) was prepared.

Since the test material was introduced directly, an analytical verification was not

essential for the interpretation of the results.

As a parameter for the activity of the sludge, the respiration rate was measured with an oxygen

probe. The decrease of the respiration rate was calculated on the basis of the oxygen

consumption per hour.

The respiration rate in the test vessels was not relevantly inhibited. There was no concentration

related effect. The NOEC was equal or higher than the solubility limit of the test substance.

The inhibitory effect of the test and the reference substance at a particular concentration was

expressed as a percentage of the mean respiration rate of the controls