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:
2006/07/27-2006/11/23
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: This study was performed accoting to OECD guideline no. 201 and under GLP regulation.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2006
Report Date:
2006

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Dihydroxyacetone

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Samples were taken at the start (0h) and the end (72h) of the study)

Test solutions

Vehicle:
no
Details on test solutions:
Reconstituted water was used as the test solution. The study was performed as a limit test with a DHA concentration of 100 mg/L.

Test organisms

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

Study design

Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
72 h

Test conditions

Test temperature:
The test temperature was in the range of 23 - 24°C
pH:
The pH values were in the range of 7.82 - 8.80
Nominal and measured concentrations:
The nominal DHA concentration of the test item group was 100 mg/L. HPLC measurements resulted in DHA concentrations of 98.4 mg/L (0h) and 96.0 mg/L (72 hours), respectively.

Results and discussion

Effect concentrations
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
>= 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Remarks:
validity criteria of OECD 201 are fulfilled
Conclusions:
An aqueous solution of 100 mg/L of Dihydroxyacetone revealed no aquatic toxicity in Desmodesmus subspicatus. The 72 hours EC50 was > 100 mg/L (limit test) and, thus, could not be determined in this test.
Executive summary:

The influence of Dihydroxyacetone on the growth and growth rate of the green algae species Desmodesmus subspicatus was tested. The study design included one control and one test material group with three replicates, each containing about 100 mL reconstituted water or test medium and 10,000 cells/mL at the start of the experimental phase. The algae were exposed to a solution of nominal 100 mg/L and the study was performed as a limit test in an open static test system. The growth was calculated after 24, 48, and 72 hours exposure in the test medium.

At the start, the analytically determined concentration was about 98 % of the nominal concentration. At the end of the experimental part, the analytically determined test material concentration was 96 % of the nominal concentration. The test material concentration could be maintained at > 80 % of the initial concentration and, thus, the nominal value was regarded as equivalent to the analytical value. For Dihydroxyacetone, the following nominal and analytical EC50 values and no effect concentration for Desmodesmus subspicatus were determined:

EbC50 > 100mg/L

ErC50 > 100mg/L

NOEC >= 100mg/L

The data obtained indicate no aquatic toxicity in the test system under the conditions of the experiment.