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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
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP study according to OECD / EU guidelines

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
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

Sampling and analysis

Analytical monitoring:
yes

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 concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
0.024 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
0.024 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
0.017 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
0.028 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
0.047 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
0.024 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate

Any other information on results incl. tables

After 72 h algae were transferred from concentrations 0.0243 - 0.0970 mg/L and control to fresh untreated medium and allowed to grow for further 2 - 4 d under test conditions. The test item effect was observed to be reversible at these concentrations. Therefore, there is potential for recovery following exposure up to 0.0970 mg/L (highest test concentration).

Applicant's summary and conclusion

Conclusions:
In the study according to OECD Guideline 201 3,4’-Dichlordiphenylether was found to inhibit the growth of the freshwater green
alga Desmodesmus subspicatus at mean measured test item concentrations = 0.0243 mg/L
(biomass growth) and = 0.0473 mg/L (growth rate). The EC50-values with 95 % confidence intervals
for inhibition of biomass growth (EbC50) and specific growth rate (ErC50) after 72 h were 0.0237
(0.0229 - 0.0245) and 0.0284 (0.0276 - 0.0291) mg/L, respectively.
Inhibition effects were found to be reversible up to 0.0970 mg/L, the highest tested concentration.
All effect levels are given based on mean measured concentrations of the test item 3,4’-
Dichlordiphenylether.