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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: A re-evaluation of the acute algal report finds this to be a well-documented study, which was conducted according to the EEC test guideline and in compliance with GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1993
Report date:
1993

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
EU Method C.3 (Algal Inhibition test)
Deviations:
not specified
GLP compliance:
yes

Test material

Constituent 1
Reference substance name:
Soybean oil, epoxidized
EC Number:
232-391-0
EC Name:
Soybean oil, epoxidized
Cas Number:
8013-07-8
IUPAC Name:
8013-07-8

Sampling and analysis

Analytical monitoring:
no
Details on sampling:
Test concentrations:
Nominal: 1.23, 3.7, 11, 33, and 100 mg test substance/l
Actual initial: 0.7, 2.3, 6.8, 24.0, and 81.0 mg test substance/l
Controls: Blank: water
Vehicle: 2.0 mg alkylphenolpolyglycolether (ARKOPAL)/l
Replicates: Each test concentration was tested in 3 replicates, the blank control in 6.
Remarks: Calculated amounts of the stock solution to produce the desired test concentrations were given into the water
and were homogeneously distributed. The algae were then transferred into the flasks. The test substance was homogeneously distributed in the test vessels at all test times and test concentrations.

Test solutions

Vehicle:
not specified
Details on test solutions:
Stock solution: 100.4 mg test substance and 2 ml 0.1% alkylphenopolyglycolether (ARKOPAL) in dist water were mixed and made up to 1000 ml with water.

Test organisms

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

Study design

Test type:
not specified
Water media type:
not specified
Limit test:
no

Test conditions

Test temperature:
Temperature was continuously measured and maintained at 23 +/- 1 C.
pH:
pH was measured at 0h and 72h exposure.
Reference substance (positive control):
not specified

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
8 mg/L
Nominal / measured:
meas. (initial)
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
0.7 mg/L
Nominal / measured:
meas. (initial)
Details on results:
The EbC-50 values were calculated according to the maximum likelihood method, logit model.

Applicant's summary and conclusion

Validity criteria fulfilled:
not specified
Conclusions:
A re-evaluation of the acute algal report finds this to be a well-documented study, which was conducted according to the EEC test guideline and in compliance with GLP. An independent statistical analysis of the cell density data confirmed that the reported EbC50 value (8.0 mg/L) has correctly accounted for inhibition by the test vehicle (alkylphenolpolyglycolether). Whereas poor recovery of test substance was observed after 72 h (by UV/VIS spectroscopy), this could be attributed to test substance falling out of solution following its initial dissolution via the solvent vehicle (DMF).

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