Registration Dossier

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:
toxicity to aquatic algae and cyanobacteria
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 201 (Alga, Growth 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:
yes

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
72 h

Results and discussion

Effect concentrations
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 0.001 mg/L
Basis for effect:
growth rate

Any other information on results incl. tables

Sorafenibtosylate had no concentration-depended inhibitory effect on the growth of Desmodesmus subspicatus. The ErC50 (growth rate) was > 0.000536 mg/L on the basis of measured concentrations. The NOEC/growth rate was ¿ 0.000536 mg/L, the LOEC was > 0.000536 mg/L.

Due to the low solubility of the est compound, the exact test concentrations in the test vessels could not be determined.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
sorafenibtosylate was considered to be not toxic to the green algae Desmodesmus
subspicatus, since the NOEC was higher than the solubility limit.
Executive summary:

The test substance sorafenibtosylate was incubated in an aqueous solution including nutrients with an algae population of Desmodesmus subspicatus for a test duration of approximately 72 hours in an electronically controlled dosing and incubation apparatus. The nutrient solution was made up of mainly ammonium, phosphates and some trace elements. For the preparation of the test solutions a suspension with a nominal loading of 100 mg/L, sorafenibtosylate, was suspended in water, ultrasonified for approximately 30 min and constantly stirred for approximately 24 hours. This suspension was filtered through a glass-fiber filter. The resulting solution was used for the preparation of the test solutions. The highest concentration was a 1:1.25 dilution obtained by adding nutrient solution and inoculum, the further concentrations were obtained by dilutions of 1:5, 1:10, 1:25, 1:50 and 1:100 with demineralized water, nutrient solution and inoculum. Additionally, a control solution was prepared with demineralized water without test material. A sample was taken for the concentration analysis by HPLC-MS (stock solution) before the test solutions were prepared. The concentration of sorafenibtosylate in the stock solution was 0.00067 mg/L. The further test concentrations were extrapolated from the result of the HPLCMS- analysis. There were between 0.0007 and 0.536 µg/L. The algae were exposed to each concentration in triplicate. Six vessels were prepared for the control. The algae were incubated under standardized conditions (continuous light, controlled temperature). As a parameter for the growth of the algae population, the fluorescence of the algae cells was measured with a fluorescence-photometer. The growth rate was calculated on the basis of the fluorescence and served as basis for evaluation.

Sorafenibtosylate had no concentration-depended inhibitory effect on the growth of Desmodesmus subspicatus. The ErC50 (growth rate) was > 0.000536 mg/L on the basis of measured concentrations. The NOEC/growth rate was ¿ 0.000536 mg/L, the LOEC was > 0.000536 mg/L.