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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Administrative data

toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
key study
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: According to OECD guideline under GLP
Cross-referenceopen allclose all
Reason / purpose for cross-reference:
reference to same study
Reason / purpose for cross-reference:
reference to other study

Data source

Reference Type:
study report
Report date:

Materials and methods

Test guideline
according to guideline
OECD Guideline 201 (Alga, Growth Inhibition Test)
GLP compliance:

Test material

Constituent 1
Reference substance name:
Automatically generated during migration to IUCLID 6, no data available
Automatically generated during migration to IUCLID 6, no data available
Details on test material:
- Name of test material (as cited in study report): Hydroxypropinol
- Analytical purity: 98.9%
- Lot/batch No.: 59002501

Sampling and analysis

Analytical monitoring:

Test solutions


Test organisms

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

Study design

Test type:
Water media type:
Total exposure duration:
72 h

Results and discussion

Effect concentrationsopen allclose all
72 h
Dose descriptor:
Effect conc.:
45 mg/L
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
72 h
Dose descriptor:
Effect conc.:
57 mg/L
Nominal / measured:
meas. (initial)
Conc. based on:
test mat.
Basis for effect:
growth rate

Any other information on results incl. tables

Table 1: Biomass, growth rate and inhibition of biomass and growth rate after 72 hours exposure time

 Concentration of Test Substance (mg/L)    Area below the growth curves    Percentage inhibition of the growth    Average specific growth rates    Percentage inhibition of the growth rate  
    A    Ai   µ µi
0 692447 0 1,4367 0
3,8 726695 -4,95 1,4472 -0,73
7,6 741762 -7,12 1,4723 -2,48
15,3 719036 -3,84 1,4552 -1,28
30,5 648612 6,33 1,4435 -0,47
58,2 103587 85,04 0,6457 55,06

Applicant's summary and conclusion

Validity criteria fulfilled:
Hydroxypropinol produced inhibition effects on the growth of Senedesmus subspicatus ≥ 30.5 mg/L.
Executive summary:

The test item Hydroxypropinol was incubated in an aqueous solution including nutrients with an algae

population of Scenedesmus subspicatus for a test duration of approximately 72 hours.

For the preparation of the test solutions a suspension with a nominal loading of 100 mg/L

was stirred for 24 hours. The resulting solution served as the highest concentration (saturated solution). It

was further diluted for concentration levels of 1 :2, 1 :4, 1:8 and 1 :16 with nutrient solution.

The organic carbon concentration of the saturated solution was analysed with a DOC analyzer

at the start and end of the incubation. The test item concentration was calculated on the basis

of the molecular formula. The mean measured concentration of the saturated stock solution

was determined with 61.1 mg/L. The further test concentrations were extrapolated trom the

result of the DDC-analysis and are shown in the table below.

The algae were exposed to each concentration in triplicate. Six vessels were prepared for the

control. The algae were incubated on a shaker under continuous light and a temperature of 22.5 - 24.8 °C.

As a parameter for the growth of the algae population, the cell density of the test and control

solutions were measured via Chlorophyll-a-f1uorescence, excitation at 435 nm, emission

685 nm. Out of the f1uorescence va lues cell density values were calculated according to a

calibration curve.

The increase of biomass and the growth rate were calculated on the basis of the cell density.

The calculated biomass and growth rate of each concentration were compared to those of the

controls, and the inhibition was calculated.

Hydroxypropinol had a concentration-depended inhibitory effect on the growth of Scenedesmus

subspicatus. The EbC50 (biomass) was 45.0 mg/L [95% confidence limits: 42.8 - 47.2], the ErC50 (growth rate) was 57.0 mg/L [95% confidence limits: 55.1 - 58.9] on the basis of measured concentrations.

Consequently, Hydroxypropinol is slightly toxic to the green algae Scenedesmus subspicatus.