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:
other information
Study period:
September 28,2001 to December 19,2001
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
This study (with the exception of the pre-experiments as mentioned in the report) has been performed in compliance with the Swiss Ordinance relating to Good Laboratory Practice, adopted February 2"d, 2000 (RS 813.016.51). This Ordinance is based on the OECD Principles of Good Laboratory Practice, as revised in 1997 and adopted November 26th, 1997 by decision of the OECD Council [C(97) 186/Final].

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2001
Report Date:
2001

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
Details on test material:
Expiration date: June 08,2002
Aggregate state / physical form at room temperature: Solid / powder
Color: White
Storage conditions: Refrigerator, at approx. 4 OC under N2 (for quality reasons).

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:
yes
Total exposure duration:
72 h

Results and discussion

Any other information on results incl. tables

A limit test was performed in accordance with the EU Commission Directive 92/69/EEC to demonstrate that the test item has no toxic effect on Scenedesmus subspicatus up to the concentration of nominal100 mg/L.

 

The analytically determined test item concentration in the analyzed test medium samples amounted to 96 mg/L at the start of the test. In this test medium, incubated under the test conditions during the test period (but without algae), a decrease of the test item concentration was determined. At the end of the test, 74% of the nominal value was found. This decrease was considered to be due to a loss by hydrolysis of the test item. The mean measured concentration (calculated as the average over all measurements per test concentration) was 85% of nominal. The biological results are related to the nominal test item concentration of 100 mg/L as well as to the mean measured concentration of 85 mg/L.

 

The mean algal cell densities in the treated test medium of nominal 100 mg/L were slightly higher than those in the parallel control culture throughout the entire test duration.Thus, the test item Acetylfuranoside clearly had no inhibitory effect on the growth of Scenedesmus subspicatus during the exposure period of 72 hours at the nominal test concentration of 100 mg/L (mean measured 85 mg/L). This test concentration was therefore determined as the 72-hour NOEC (highest concentration tested without toxic effects after a test period of 72 hours). This value might even be higher, but concentrations in excess of 100 mg/L have not been tested, according to EU Commission Directive 92/69/EEC.

 

The 72-hour LOEC (lowest concentration tested with toxic effects), and the 72-hour EC50 for the algal biomass b and growth rate r could not be quantified due to the absence of a toxic effect of Acetylfuranoside at the tested concentration. However, these parameters were clearly higher than nominal100mg/L (mean measured 85 mg/L).

 

The microscopic examination of the algal cells after 72 hours test period showed no difference between the algae growing in the test concentration of nominal 100 mg/L and the algal cells in the control. The shape and size of the algal cells growing in test medium containing the test item at up to this test concentration were obviously not

affected.

 

In the control the cell density increased from nominal N=1 x l04cells/mL at the start of the test(0hours) to N= 76 x 104cells/mL (mean value) after 72 hours. Thus, the algal growth in the control was sufficiently high under the test conditions and the validity criterion of increase of cell density by at least a factor of 16 over the duration of the study was fulfilled.

 

Noremarkable observations were made concerning the appearance of the test medium. It was a clear solution throughout the test period.

 

At the start of the test, the pH values in the test medium and the control were 8.0 and 7.9. At the end of the test, pH values of 9.0 and 8.8 were measured. The water temperature was 23°C during the test.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The 72-hour EC50 and the 72-hour EC100 were clearly higher than nominal 100 mg/L (mean measured 85 mg/L). These values could not be quantified due to the absence of toxicity of Acetylfuranoside up to the tested concentration.
Executive summary:

The influence of the test item Acetylfuranoside on the growth of the green algal species

Scenedesmus subspicatus CHODAT was investigated in a 72-hour static test according to the EU Commission Directive 92/69/EEC, C.3, 1992, and the OECD Guideline No. 201, 1984.

 

A limit test was performed in accordance with the guidelines to demonstrate that the test item has no toxic effect on the algae up to and including the concentration of nominal 100 mg/L. Thus, the only concentration tested was nominal 100 mg/L and a control.

 

The analytically determined test item concentration in the analyzed test medium samples amounted to 96 mg/L at the start of the test and 74 mg/L at the end of the test. The decrease was considered to be due to a loss by hydrolysis of the test item. The mean measured concentration (calculated as the average over all measurements per test concentration) was 85% of nominal. The biological results are related to the nominal test item concentration of 100 mg/L as well as to the mean measured concentration of 85 mg/L.

 

The test item Acetylfuranoside had clearly no inhibitory effect on the growth of Scenedesmus subspicatus during the exposure period of 72 hours at the test concentration of nominal 100 mg/L. The 72-hour NOEC (highest concentration tested without toxic effects after the exposure period of 72 hours) of Acetylfuranoside toScenedesmus subspicatus was determined to be nominal 100 mg/L (mean measured 85 mg/L). This value might even be higher, but concentrations in excess of 100 mg/L have not been tested, according to EU Commission Directive 92/69/EEC.

 

The 72-hour EC50 and the 72-hour EC100 were clearly higher than nominal 100 mg/L (mean measured 85 mg/L). These values could not be quantified due to the absence of toxicity of Acetylfuranoside up to the tested concentration.