β-methyl-3-(1-methylethyl)benzenepropanal

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

23 June 1999 - 03 September, 1999

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Version / remarks:

1984

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Version / remarks:

1992

GLP compliance:

yes

Specific details on test material used for the study:

Batch No. 9000332322;
Purity 98.9%;
Expiry Date : 28 May, 2000

Analytical monitoring:

yes

Remarks:

HPLC UV-VIS

Details on sampling:

Samples of the upper three test concentrations were taken and analysed at the beginning of the exposure (Time 0) and at the end of the exposure (72 hours).

Vehicle:

no

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

The nominal test concentrations were :
0.46 mg/L
1.0 mg/L
2.2 mg/L
4.6 mg/L
10 mg/L
22 mg/L

The test medium of the highest test concentration of nominal 22 mg/L was prepared by dissolving 22 mg of the test substance completely in 1L of test water (synthetic water) by stirring for 2 minutes. No additional solvent was used. Adequate volumes of the intensively mixed test medium were added to test water to prepare the test media of the lower test concentrations. Additionally, a Control was tested in parallel (test water without addition of the test item). The test media were prepared just before inoculation of the algae.

The test concentrations were based on the results of a range-finding test.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Hardness:

24 mg/L as CaCO3.

Test temperature:

21 - 22 °C

pH:

pH 8.1 - 8.9

Nominal and measured concentrations:

The Time 0 and 72 hour samples for the upper three test concentrations were analysed (4.6 mg/L, 10 mg/L and 22 mg/L).

Time 0 starting exposure concentrations were between 72 - 79% of Nominal, and demonstrated stability over the course of the 72 hour exposure, with between 67 - 78% recovered in the 72 hour analyses.

Nominal Concn. Mean Measured
(mg/L) (mg/L)

Control Not Detected
4.6 mg/L 3.2 mg/L
10 mg/L 7.2 mg/L
22 mg/L 17 mg/L

Details on test conditions:

Algal Cells at Start : 10'000 cells/mL;
Vessels : 50 mL Erlenmeyer flasks;
Volume of Algal Suspension : 15 mL;
Replicates : 3 replicates per test concentration and 6 replicates for the Control;
Temperature of Incubation : 21 - 22°C;
Lighting : Continuous, 8400 Lux (mean value);
Test Duration : 72 hours

Reference substance (positive control):

no

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

11 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% CI: 7.4 - 20 mg/L

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

6.4 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% CI: 1.4 - 9.2 mg/L

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

3.2 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

other: Growth and Biomass

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

8.4 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other:

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

4.8 mg/L

Nominal / measured:

meas. (arithm. mean)

Basis for effect:

biomass

Details on results:

The test item had a significant inhibitory effect on the biomass and growth rate of Scendesmus subspicatus after the exposure period of 72 hours at and above the test concentration of 7.2 mg/L. Therefore, the NOEC was 3.2 mg/L.

In the Control the algal cells multiplied in number by 56.3-times over the course of the 72 hour exposure.

Validity criteria fulfilled:

yes

Conclusions:

The EC and NOEC values for Growth Rate and Biomass determined for Scendesmus subspicatus exposed to Florhydral for 72 hours under the test conditions described, herein, are :
72 hour ErC50 = 11 mg/L
72 hour ErC10 = 6.4 mg/L
72 hour EbC50 = 8.4 mg/L
72 hour EbC10 = 4.8 mg/L
72 hour NOEr,bC = 3.2 mg/L

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

05 March, 2015 - 23 July, 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

FLORHYDRAL is a primary aldehyde and undergoes transformation to the following two Primary Degradates :
- Florhydral-Acid (GR-81-6079), and
- Florhydral-Alcohol (GR-82-4337)
Both of the above primary metabolites have been observed in an OECD 301C study, and were also observed to have been formed in an OECD 203 study.

In the OECD 301C, on Day 28 72-77% of the starting dose had been transformed in to Florhydral-Acid, and 18 - 20% was present as the Florhydral-Alcohol. Both entities, and in particular the Florhydral-Acid are relevant for consideration within environmental studies.

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Version / remarks:

23 March, 2006, updated Annex V 28 July, 2011

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

GR-81-6079 (Florhydral-Acid) :
Lot No.: GLN00538-026-DF;
Purity : 97.0%
Date of Expiry : 22 July, 2015

Analytical monitoring:

yes

Remarks:

GC-MS

Details on sampling:

Samples from the Control and the 5 exposure concentration levels were sampled for analysis at Time 0 and at the end of the exposure at 72 hours.

In addition, samples at the mid-level exposure concentration (C3) without algal cells were exposed to light and a further sample stored in the dark (no algae) and sampled for analysis at 72 hours as light/drak control samples.

Vehicle:

no

Details on test solutions:

Based on the results of a preliminary non-GLP range finding test, the following dilution steps
in a geometrical series (spacing factor: square root of ten) were tested in the definitive test:

1.00, 3.16, 10.0, 31.6 and 100% of a filtrate at a loading rate of 100 mg/L

Additionally, the test organisms were exposed under control conditions (non-treated test
medium).

The test item was applied once at the beginning of the exposure period. Three replicate
vessels were used for the test item concentrations, and six replicate vessels for the control.
Two additional test vessels without algae were prepared for chemical analysis of the
intermediate test item concentration (C3, 10.0%) at the end of the test, in order to assess test
item stability during exposure without the presence of algae (stability samples).

Two additional test vessels without algae were prepared for chemical analysis of the
intermediate test item concentration (C3, 10.0%) at the end of the test. The test vessels were
exposed in darkness, in order to assess test item stability during exposure without the
presence of algae and light (light/dark stability samples).

The additional vessels were maintained under the same test conditions as the vessels with
algae, with the exceptions described above.

The test period (exposure of test organisms to the test solutions in a static system) was
72 hours.

Preparation of the Stock/Application and Test Solutions :
One day before the test start a stock solution (S1) was prepared by diluting 0.2015 g of the
test item in 2000 mL of growth medium, resulting in a nominal concentration of 100 mg test
item/L. This stock solution was stirred overnight on a magnetic stirrer at room temperature in
the dark.

At the day of exposure start, the stock solution was visually examined for undissolved test
material, after one hour without stirring. Test item material was visible in the medium and on
the surface of the stock solution. Therefore, the stock solution was filtered through a glassfibre
filter with an average retention capacity of 0.4 μm (Type: MN GF 5, diameter: 90 mm).

The filtrate was visually checked, and no undissolved material were visible. This stock solution (filtrate) was used to prepare the test solutions.

The volume of the stock solution were large enough to prepare the test solutions and all
analytical samples.

After temperature adaptation of the test solutions, 8.888–22.222 mL of the algal pre-culture
(Desmodesmus subspicatus) were added to each of the volumetric flasks containing 400–
1000 mL of the test solutions, respectively, to achieve an algal cell concentration of nominally
0.5×104 cells/mL. These manipulations were performed under a laminar flow box. The test
solutions were homogenised by manual shaking 10 times overhead, before adding 100±5 mL
of the test media to each test vessel to ensure a homogeneous distribution of the algal cells.

The test vessels were placed onto a shaker under light- and temperature-controlled
conditions.

The medium was sterilised by sterile filtration (pore size 0.2 μm) before use. All glassware
and materials used for testing purposes were sterilised for at least 3 hours at 150± 0°C using
a heating furnace.

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

Characterisation of the Test System (Test Organism) :
The test system used in this study was the freshwater algae Desmodesmus subspicatus
(SAG 86.81).

The organisms were originally supplied by Sammlung von Algenkulturen, Albrecht-von-
Haller-Institut, Universität Göttingen, Germany.

The unicellular alga Desmodesmus subspicatus was chosen as a representative of
freshwater algae. The selection of the test system was based on the test guideline.

Pre-Culture Conditions :
To adapt the algae to the test conditions, a pre-culture was inoculated by a liquid algal
culture and incubated under test conditions.
Species: Desmodesmus subspicatus (SAG 86.81)
Supplier: Sammlung von Algenkulturen, Albrecht-von-Haller-Institut, Universität Göttingen, Germany
Date of receipt: January 08, 2015
Charge No. (ECT): B/080115/A
pH-value of the algal medium: 8.1
Culture medium: Mod. OECD medium (OECD 201, EN ISO 8692)
Volume of liquid stock culture per pre-culture vessel: 100±5 mL
Pre-culture vessels: 300 mL Erlenmeyer flasks
Number of replicates: 2
Light: Permanent illumination (24/0 h light/dark); fluorescent tubes of universal white type (Osram Lumilux L 58W/865)
Light intensity: 60–120 μE m–2 s–1
Shaker: 100±5 oscillations/min
Temperature in the test room: 21–24 °C, controlled at ±2 °C

Test type:

static

Water media type:

freshwater

Remarks:

OECD Medium modified with EDTA addition

Limit test:

no

Total exposure duration:

72 h

Test temperature:

22.8 - 23.2 °C

pH:

pH6.6 - 10.2

The pH-value in the treatments increased by a maximum of 2.6 units. Therefore, the pH
exceed the required range (pH should not vary by more than 1.5 units) as given in the
guideline and the study plan. This deviation has no influence on the integrity of the study
results, since these exceedance was observed in all well-growing treatment levels including
the control.

Nominal and measured concentrations:

Based on the results of a preliminary non-GLP range finding test, the following dilution steps
in a geometrical series (spacing factor: square root of ten) were tested in the definitive test:

1.00, 3.16, 10.0, 31.6 and 100% of a filtrate at a loading rate of 100 mg/L.

Nominal and Geometric Mean Measured concentrations were, as follows :

Nominal Geom. Mean Measured
(% of 100 mg/L Filtrate loading rate) (mg/L)

Control Not Detected (<0.12 mg/L)
1.00% 1.01 mg/L
3.16% 2.69 mg/L
10.0% 9.19 mg/L
31.6% 27.2 mg/L
100% 90.6 mg/L

Recovery of test item in samples with respect to Nominal expected loading rate was between 84 and 115% of Nominal.

Details on test conditions:

Exposure Conditions :
Test units: 300 mL Erlenmeyer flasks
Volume of test solution per test vessel: 100±5 mL
Age of the pre-culture: 3 days
Number of cells per mL in the pre-culture before inoculating the test solution: 22.5×104
Number of cells per mL test solution at the beginning of the test: 0.5×104
Number of replicates per test item concentration: 3
Number of replicates in the control: 6
Number of replicates for stability check (intermediate concentration level without algae):
2 (without algae) + 2 (without algae, without light)
Test medium: OECD medium (modified)
pH of untreated test medium: 7.9
pH in test solution (exposure): 6.6–10.2;
Light regime: 24 h light/0 h dark
Type of light: Fluorescent tubes of universal white type (Osram Lumilux L 58W/865)
Light intensity: Mean 81.6 μE m–2s–1;
Temperature: 22.8–23.2, mean 22.97 °C;
Shaker: 100±5 oscillations/min; the test vessels were placed randomly on the shaker
Test duration (exposure): 72 hours
Counting of algae: Daily

Reference substance (positive control):

yes

Remarks:

Potassium Dichromate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 90.6 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

54.7 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% CI : 49.8 - 58.7 mg/L

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

9.19 mg/L

Nominal / measured:

meas. (geom. mean)

Basis for effect:

other: Growth Rate and Biomass

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

67.4 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 95% CI : 61.9 - 73.3 mg/L

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

26.3 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 95% CI : 21.0 - 30.9 mg/L

Details on results:

A clear concentration-response relationship could be observed for both biological parameters
growth rate and yield during the exposure period.

The factor of biomass increase in the control replicates was 114 within the 72-hour exposure
period. Therefore, the data were in the required range (factor of at least 16).

Observations :
In none of the concentration levels, deformed and/or damaged algal cells were observed during
microscopic inspection.

Results with reference substance (positive control):

Reference Item and Results of Reference Testing :
A reference test using potassium dichromate (K2Cr2O7) as reference item was performed in
December 2014.

Result: Growth rate ErC50 (0–72 h): 0.940 mg/L (0.900 – 0.983 mg/L; 95%-CL)

This result is in accordance with the range given in the international ring test (ISO (2004);
Water Quality – Freshwater algal growth inhibition test with unicellular green algae.

European Standard EN ISO 8692, October 2004.) mentioned in OECD guideline 201, the
ErC50 (72h)-values for potassium dichromate obtained from different laboratories should be
0.84 mg/L with a standard deviation of 0.12 mg/L. Therefore the results of this reference test
are acceptable and the test conditions are reliable.

Cell number as dependent on concentration of the test item :

Cell number per mL (divided by 104) in Desmodesmus subspicatus as dependent on

concentration of the test item and time.

Inhibition of Yield in relation to Concentration and Time :

Inhibition of Yield: Yield per mL (divided by 104) of Desmodesmus subspicatus in

relation to the concentrations of the test item and %Inhibition caused by the test item after

72 hours

Inhibition of Growth Rate in relation to Concentration and Time :

Inhibition of Growth Rate: Growth Rate of Desmodesmus subspicatus in relation to

the concentrations of the test item and %Inhibition caused by the test item after 72 hours

Validity criteria fulfilled:

yes

Conclusions:

The results of the algal inhibition study performed with Florhydral-Alcohol (GR-81-6079) and Desmodesmus subspicatus under the conditions of an OECD 201:
72 hour ErC50 > 90.6 mg/L
72 hour ErC10 = 54.7 mg/L
72 hour NOEr,yC = 9.19 mg/L
72 hour EyC50 = 67.4 mg/L
72 hour EyC10 = 26.3 mg/L

Reference 3

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

12 March, 2015 - 23 July, 2015

Reliability:

1 (reliable without restriction)

Justification for type of information:

FLORHYDRAL is a primary aldehyde and undergoes transformation to the following two Primary Degradates :
- Florhydral-Acid (GR-81-6079), and
- Florhydral-Alcohol (GR-82-4337)
Both of the above primary metabolites have been observed in an OECD 301C study, and were also observed to have been formed in an OECD 203 study.

In the OECD 301C, on Day 28 72-77% of the starting dose had been transformed in to Florhydral-Acid, and 18 - 20% was present as the Florhydral-Alcohol. Both entities, and in particular the Florhydral-Acid are relevant for consideration within environmental studies.

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Version / remarks:

23 March, 2006, updated Annex V, 28 July, 2011

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

GR-82-4337 (Florhydral-Alcohol) :
Lot No. : GLN00538-034-Fr10+Fr11;
Purity : 98.7%
Expiry Date : 22 July, 2015

Analytical monitoring:

yes

Remarks:

GC-MS

Details on sampling:

Following a Range-Finding study, the main test was set-up and included Control and six different exposure concentrations with a spacing factor of 2.2.

Samples of the Control and the six concentration levels were taken for analysis at the beginning of the exposure (Time 0) and at the end of the exposure (72 hours).

The exposure concentrations were expressed as % filtrate of a 100 mg/L stock solution : 100%, 45.5%, 20.7%, 9.39%, 4.27%, 1.94%.

Additional Light/Dark control samples were prepared and incubated without the presence of algal cells. These solutions were prepared at the 20.7% concentration level.

Vehicle:

no

Details on test solutions:

Based on the results of a preliminary non-GLP range finding test, the following dilution steps
in a geometrical series (spacing factor: 2.2) were tested in the definitive test:

1.94, 4.27, 9.39, 20.7, 45.5 and 100% of a filtrate at a loading rate of 100 mg/L.

Additionally, the test organisms were exposed under control conditions (non-treated test
medium).

The test item was applied once at the beginning of the exposure period. Three replicate vessels
were used per test item concentration, and six replicate vessels for the control.

Preparation of Stock and Test Solutions :
One day before the test start a stock solution (S1) was prepared by diluting 0.2001 g of the
test item in 2000 mL of growth medium, resulting in a nominal concentration of 100 mg test
item/L. This stock solution was stirred overnight (24 hours) on a magnetic stirrer at room
temperature (20°C) in dark.

At day of exposure start, after one hour without stirring, the stock solution was visually observed
for undissolved test item particles. In the stock solution, test item particles were visible in the
medium and on the surface of the stock solution. Therefore, the stock solution was treated for
one hour using an ultrasonic bath discontinued by repeated stirring on a magnetic stirrer, followed by stirring for additional 30 minutes. Again the stock solution was visually observed (using the Tyndall effect) for undissolved test item material, after one hour without stirring.

Because of visible test item material in the stock solution, any non-dissolved test material forming a surface film was removed by pipetting and the stock solution was filtered through a glass-fibre filter with an average retention capacity of 0.4 μm (Type: MN GF 5, diameter: 90 mm). The filtrate was visually checked and no undissolved material were visible. This stock solution (filtrate) was used to prepare the test solution used for exposure.

The stock solution (filtrate) was prepared once to prepare the test solutions.

The volume of the stock solution were large enough to prepare the test solutions and all
analytical samples and solutions used for conditioning.

After temperature adaptation of the test solutions, 1.255 or 4.185 mL of the algal pre-culture
(Desmodesmus subspicatus) were added to each of the volumetric flasks containing 300 or
1000 mL of the test solutions, respectively to achieve an algal cell concentration of
approximately 0.5×104 cells/mL. These manipulations were performed under a laminar flow
box. The test solutions were homogenised by manual shaking 10 times overhead, before
adding 100±5 mL of the test media to each test vessel to ensure a homogeneous distribution
of the algal cells.

The test vessels were placed onto a shaker under light and temperature controlled conditions.

The medium was sterilised by sterile filtration (pore size 0.2 μm) before use. All glassware and
materials used for testing purposes were sterilised for at least 3 hours at ≥150 °C using a
heating furnace.

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

Characterisation of the Test System (Test Organism) :
The test system used in this study was the freshwater algae Desmodesmus subspicatus (SAG
86.81).

The organisms were originally supplied by Sammlung von Algenkulturen, Albrecht-von-Haller-
Institut, Universität Göttingen, Germany.

Pre-Culture Conditions :
To adapt the algae to the test conditions a pre-culture was inoculated by a liquid algal culture
and incubated under test conditions.
Species: Desmodesmus subspicatus (SAG 86.81)
Supplier: Sammlung von Algenkulturen, Albrecht-von-Haller-Institut, Universität Göttingen, Germany
Date of receipt: January 08, 2015
Charge No. (ECT): B/080115/A
pH-value of the algal medium: 7.9
Culture medium: Mod. OECD medium (OECD 201, EN ISO 8692)
Volume of liquid stock culture per pre-culture vessel: 100±5 mL
Pre-culture vessels: 300 mL Erlenmeyer flasks
Number of replicates: 2
Light: Permanent illumination (24/0 h light/dark); fluorescent tubes of universal white type (Osram Lumilux L 58W/865)
Light intensity: 60–120 μE m-2s-1
Shaker: 100±5 oscillations/min
Temperature in the test room: 21–24 C, controlled at ±2 °C.

Test type:

static

Water media type:

freshwater

Remarks:

OECD Medium, modified with EDTA.

Limit test:

no

Total exposure duration:

72 h

Test temperature:

22.7 - 23.3 °C

pH:

pH 7.5 - 9.2.

The pH-value in the test concentrations did vary by up to 1.6 pH units throughout the test duration.

Therefore, the pH slightly exceeded the required range (pH should not vary by more than 1.5
units) for one concentration level (C1, 1.94% of filtrate), as given in the guideline and the study
plan. However, this minor deviation is not considered to have an impact on the integrity of the
study.

Nominal and measured concentrations:

Samples from the test solutions were analysed to determine actual levels of the test item in
comparison to nominal loading rates. The measured concentrations range between 76–83%
at start and 61–88% at end of the exposure period. No distinct decrease of test item
concentration throughout the exposure period was determined. The measured concentrations
were not stable within ±20% throughout the exposure period (range: 75–112% of initial
measured concentrations).

The geometric mean was calculated using the test item concentrations measured at the start and the end of the exposure period. The following values were determined:

Nominal Geometric Mean Measured
(% filtrate of 100 mg/L) (mg/L)

Control Not Detected (< 0.18 mg/L)
1.94% 1.33 mg/L
4.27% 3.40 mg/L
9.39% 6.78 mg/L
20.7% 16.7 mg/L
45.5% 36.5 mg/L
100% 83.2 mg/L

Details on test conditions:

Exposure Conditions :
Test vessels: 300 mL Erlenmeyer flasks
Volume of test solution per test vessel: 100±5 mL
Age of the pre-culture: 4 days
Number of cells per mL in the pre-culture before inoculating the test solutions: 119.5×104
Number of cells per mL test solution at the beginning of the test: 0.5×104
Number of replicates per test item concentration: 3
Number of replicates in the control: 6
Number of replicates for stability check (intermediate concentration level without algae):
2 (without algae) + 2 (without algae, without light)
Test medium: OECD medium (modified)
pH of test medium: 7.9
pH in test solutions: 7.5–9.2;
Light regime: 24 h light/0 h dark
Type of light: Fluorescent tubes of universal white type (Osram Lumilux L 58W/865)
Light intensity: 72.5–88.8 μE m–2s–1; mean 81.1 μE m–2s–1;
Temperature: 22.7–23.3, mean 22.92 °C;
Shaker: 100±5 oscillations/min; the test vessels were placed randomly on the shaker;
Test duration (exposure): 72 hours;
Counting of algae: Daily

Reference substance (positive control):

yes

Remarks:

Potassium DiChromate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

16.8 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% CI : 16.4 - 17.2 mg/L

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

6.69 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% CI : 6.34 - 7.04 mg/L

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

3.4 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

7.77 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 95% CI : 7.20 - 8.41 mg/L

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

3.41 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 95% CI : 2.88 - 3.88 mg/L

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

1.33 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Details on results:

A clear concentration-response relationship could be observed for both biological parameters
growth rate and yield during the exposure period.

Results with reference substance (positive control):

A reference test using potassium dichromate (K2Cr2O7) as reference item was performed in
December 2014.

Result: Growth rate ErC50 (0–72 h): 0.940 mg/L (0.900 – 0.983 mg/L; 95%-CL)

This result is in accordance with the range given in the international ring test (ISO (2004);
Water Quality – Freshwater algal growth inhibition test with unicellular green algae. European
Standard EN ISO 8692, October 2004.) mentioned in OECD guideline 201, the ErC50 (72h)-
values for potassium dichromate obtained from different laboratories should be 0.84 mg/L with
a standard deviation of 0.12 mg/L. Therefore the results of this reference test are acceptable
and the test conditions are reliable.

Cell Number as Dependent on Concentration of the Test Item and Time :

The factor of biomass increase in the control cultures was 126.0 within the 72-hour exposure

period. Therefore, the data was in the required range (factor of at least 16), as given in the

guideline and the study plan.

Inhibition of Yield in Relation to Concentration and Time :

Inhibition of Growth Rate in relation to Concentration and Time :

Validity criteria fulfilled:

yes

Conclusions:

The results of the algal inhibition study performed with Florhydral-Alcohol (GR-82-4337) and Desmodesmus subspicatus under the conditions of an OECD 201:
72 hour ErC50 = 16.8 mg/L
72 hour ErC10 = 6.69 mg/L
72 hour NOErC = 3.40 mg/L
72 hour EyC50 = 7.77 mg/L
72 hour EyC10 = 3.41 mg/L
72 hour NOEyC =1.33 mg/L

Description of key information

AQUATIC TOXICITY :

FLORHYDRAL

Algae 72 hour ErC50 = 11 mg/L

Algae 72 hour ErC10 = 6.4 mg/L

Additionally, full base-set aqautox studies are available for Florhydral-Acid (GR-81-6079) and Florhydral-Alcohol (GR-82-4332). Florhydral-Acid is the most relevant transformation product of FLORHYDRAL (via direct oxidation of the aldehyde group). The end-points determined are, as follows :

FLORHYDRAL-ACID (GR-81-6079) :

Algae 72 hour ErC50 > 90.6 mg/L

Algae 72 hour ErC10 = 54.7 mg/L

FLORHYDRAL-ALCOHOL (GR-82-4332) :

Algae 72 hour ErC50 = 16.8 mg/L

Algae 72 hour ErC10 = 6.69 mg/L

Thus, in the natural environment, FLORHYDRAL is rapidly transformed in to metabolites of lower toxicity than the Parent. The Alcohol will be transformed to the Acid, which is significantly less toxic than the Parent.

Key value for chemical safety assessment

EC50 for freshwater algae:

11 mg/L

EC10 or NOEC for freshwater algae:

6.4 mg/L

Additional information

AQUATIC TOXICITY :

FLORHYDRAL

Algae 72 hour ErC50 = 11 mg/L

Algae 72 hour ErC10 = 6.4 mg/L

Additionally, full base-set aqautox studies are available for Florhydral-Acid (GR-81-6079) and Florhydral-Alcohol (GR-82-4332). Florhydral-Acid is the most relevant transformation product of FLORHYDRAL (via direct oxidation of the aldehyde group). The end-points determined are, as follows :

FLORHYDRAL-ACID (GR-81-6079) :

Algae 72 hour ErC50 > 90.6 mg/L

Algae 72 hour ErC10 = 54.7 mg/L

FLORHYDRAL-ALCOHOL (GR-82-4332) :

Algae 72 hour ErC50 = 16.8 mg/L

Algae 72 hour ErC10 = 6.69 mg/L

Thus, in the natural environment, FLORHYDRAL is rapidly transformed in to metabolites of lower toxicity than the Parent. The Alcohol will be transformed to the Acid, which is significantly less toxic than the Parent

.