3-hydroxypropiononitrile

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2008-09-22 to 2008-09-25

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study OECD 201, Limit-test, GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

3-hydroxypropiononitrile

EC Number:

203-704-8

EC Name:

3-hydroxypropiononitrile

Cas Number:

109-78-4

Molecular formula:

C3H5NO

IUPAC Name:

3-hydroxypropanenitrile

Details on test material:

- Supplier: Evonik Röhm GmbH, Darmstadt, Germany
- Purity: 99.1%
- Impurities: 0.46 % Ethylene glycol
- Lot/batch No.: 1038042701
- Expiration date of the lot/batch: 14 Nov. 2008
- Stability of test article dilution:
- Storage condition of test material: Room temperature, max. 30°C, protected from moisture and light

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Details on test solutions:

Stock solution: 200 mg/L, freshly prepared with dilution water.
Dispersion treatment: Agitation
Dilution water: According to the guideline:
Composition of Dilution water:
Component Concentration [mg/L]
----------------------------------------
NH4Cl 15
MgCl2 *6 H2O 12
CaCl2 *2 H2O 18
MgSO4 *7 H2O 15
KH2PO4 1.6
FeCl3 *6 H2O 0.064
Na2EDTA *2 H2O 0.1
H3BO3 0.185
MnCl2 * 4 H2O 0.415
ZnCl2 3 x 10-3
Na2MoO4 * 2 H2O 7 x 10-3
CoCl2 * 6 H2O 1.5 x 10-3
CuCl2 * 2 H2O 1 x 10-5
NaHCO3 50
------------------------------------------
pH-value: 8.0 ± 0.2

This medium had a nominal hardness of 0.24 mmol Ca+Mg/L.

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST SYSTEM
Test organism Desmodesmus subspicatus CHODAT SAG 86.81 (formerly Scenedesmus subspicatus CHODAT)
Reason for the selection of the test system: According to the guideline Desmodesmus subspicatus CHODAT SAG 86.81 is suitable for this kind of
study.
Origin: Sammlung von Algenkulturen (SAG), Pflanzenphysiologisches Institut der Universität Göttingen, Nikolausberger Weg 18,
D-37073 Göttingen
Method of cultivation: Fresh stocks were prepared every month on Z-Agar. Light intensity amounted 35-70 µE*m-2*s-1 for 24 h per day.
Culture medium: Nutrient medium Z according to LÜTTGE et al. (1994).

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Remarks on exposure duration:

limit test

Test conditions

Hardness:

0.24 mmol Ca+Mg/L

Test temperature:

Nominal range: 21 – 24 °C, controlled at 2 °C
Observed: min 22 °C, max. 24 °C, mean 23 °C

pH:

Control: initially pH 8.16, at 72 h: pH 8.50
100 mg/l: initially pH 7.90, at 72 h: pH 8.69

Nominal and measured concentrations:

nominal concentration: 100 mg/l

Determination of the test concentration by DOC [mg/l]

Nominal
test Test start 0 h Test end 72 h Test end 72 h
conc. (without alga) (without alga) (with alga)
[mg/L] Rep.1 Rep.2 Mean Rep.1 Rep.2 Mean Rep.1 Rep.2 Mean

100 52.2 52.1 52.1 52.3 52.0 52.2 57.4 57.1 57.3
Control 0.23 0.21 0.22 0.62 0.59 0.61 4.92 5.08 5.00

The measured DOC-values well met the expected range of the test concentrations (the theoretical carbon content of the test item is 50.2 mg/l).

Details on test conditions:

TEST ITEM
Stock solution 200 mg/L Ethylene cyanohydrin, freshly prepared with dilution water.
Dispersion treatment : Agitation
Test concentration: One limit concentration of 100 mg/L (six replicates).

CONTROL: Six replicates (without test item) were tested under the same test conditions as the test replicates.

PHYSICO -CHEMICAL DATA /Environmental Conditions
Light intensity [µE*m(Exp -2) *s(Exp -1)]: min.: 69.4; max.: 80.6; mean value: 75.7

TYPE AND FREQUENCY OF MEASUREMENT
Cell density was measured daily via Chlorophyll-a- fluorescence,
excitation at 436 nm, emission at 685 nm. Dilution water was used as background signal. The pH-value at the beginning of the test was measured out of one additional replicate of the limit concentration and control. At the end it was measured from one pool of all replicates of the limit concentration and control. The room temperature was measured continuously by a hygro-thermograph. Light intensity will be measured prior to test start.
Microscopic evaluation of the cells at the start and end of the incubation was carried out. The cells were checked for unusual cell shapes, colour
differences, differences in chloroplast morphology, flocculation, adherence of algae to test containers and agglutination of alga cells.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Results and discussion

Effect concentrations

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

Ethylene cyanohydrin

Basis for effect:

biomass

Details on results:

Range Finding Test (NON-GLP)
Results of the Range Finding Test (0 – 72 h)

Nominal
Test Item Concentration
[mg/L] Specific Growth Rate Inhibition [%] Yield Inhibition [%]
----------------------------------------------------------------------------------
100 -3 -14
10 0 2
----------------------------------------------------------------------------------

Results of the definitive test:
EC10, EC20 and EC50-Values (0-72 h) of Ethylene cyanohydrin based on the nominal test item concentration [mg/L]

EC-Values Yield inhibition
-------------------------------------
EyC10 > 100
EyC20 > 100
EyC50 > 100
-------------------------------------
Rate-related inhibition
ErC10 > 100
ErC20 > 100
ErC50 > 100
-------------------------------------

CELL DENSITIES
Nominal test item
concentration Replicate Cell density [cells/mL]
[mg/L] No. 0 h 24 h 48 h 72 h
------------------------------------------------------------------------------
100 1 4878 36818 254846 1213071
2 4878 35874 278561 1196194
3 4878 34608 306232 1292754
4 4878 38871 325924 1253038
5 4878 36234 224638 1129920
6 4878 35113 260543 1270629
-----------------------------------------------------------------
Mean 4878 36253 275124 1225934
-------------------------------------------------------------------------------
Control 1 4878 30823 187400 925284
2 4878 34576 223178 1135740
3 4878 37906 253121 1085534
4 4878 35213 210903 1158122
5 4878 37841 279207 1286957
6 4878 41139 252519 1278859
-----------------------------------------------------------------
Mean 4878 36250 234388 1145083
-------------------------------------------------------------------------------

EVALUATION AFTER 72 h
Nominal test item
concentration Replicate Yield Inhibition of yield Growth rate Rate-related inhibition
[mg/L] No. [%] [d-1] [%]
------------------------------------------------------------------------------------------------------
100 1 1208193 -5.96 1.839 -1.17
2 1191316 -4.48 1.834 -0.91
3 1287876 -12.95 1.860 -2.34
4 1248160 -9.47 1.850 -1.76
5 1125042 1.33 1.815 0.13
6 1265751 -11.01 1.854 -2.02
-----------------------------------------------------------------------------------------
Mean 1221056 -7.09 1.842 -1.35
------------------------------------------------------------------------------------------------------
Control 1 920406 1.748
2 1130862 1.817
3 1080656 1.802
4 1153244 1.823
5 1282079 1.858
6 1273981 1.856
-----------------------------------------------------------------------------------------
Mean 1140205 1.817
------------------------------------------------------------------------------------------------------
negative inhibitions = increase of growth


Section-by-Section and Average Specific Growth Rates of the Control Group

Replicate No. Specific growth rate [d-1] Mean(0 - 72 h) SD± VC % Mean VC %
section-by-section
0 – 24 h 24 – 48 h 48 – 72 h
-----------------------------------------------------------------------------------------------------------------------
Control 1 1.844 1.805 1.597 1.748 0.133 7.59 11.86
2 1.958 1.865 1.627 1.817 0.171 9.40
3 2.050 1.899 1.456 1.802 0.309 17.14
4 1.977 1.790 1.703 1.823 0.140 7.67
5 2.049 1.999 1.528 1.858 0.287 15.45
6 2.132 1.815 1.622 1.856 0.258 13.87
-----------------------------------------------------------------------------------------------------------------------
Mean 1.817
SD ± 0.04
VC % 2.23
-----------------------------------------------------------------------------------------------------------------------


DOC CONTENT OF THE TEST MATERIAL OF THE TEST MEDIA AT TEST START AND TEST END

Nominal DOC mg/L
test item
concentration
[mg/L]
Test start Test end
0 h 72 H
(without alga) (without alga) (with alga)
Parallel determination Mean Parallel determination Mean Parallel determination Mean
100 52.2 52.1 52.1 52.3 52.0 52.2 57.4 57.1 57.3
Control 0.23 0.21 0.22 0.62 0.59 0.61 4.92 5.08 5.00

The measured DOC-values well met the expected range of the test concentrations (the theoretic carbon content of the test item is 50.2 %).

Results with reference substance (positive control):

The toxicity of potassium dichromate to the unicellular freshwater green alga Desmodesmus subspicatus was determined over a period of 72 h from March 10 to 13, 2008.


EC50 Values of the Reference Item based on nominal concentrations [mg/L], (0-72 h)

Yield inhibition
---------------------------------------------------------
EyC50 0.31
95 % confidence interval 0.30 – 0.33
---------------------------------------------------------
Rate-related inhibition
---------------------------------------------------------
ErC50 0.74
95 % confidence interval 0.70 – 0.78
---------------------------------------------------------

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

In this study the effects of the test item Ethylene cyanohydrin on the growth of the freshwater green alga Desmodesmus subspicatus were tested. No
inhibiting effects on specific growth rate and yield were found in the limit concentration of 100 mg/L. The EC50-values for specific growth rate
inhibition (ErC50) and inhibition of yield (EyC50) after 72 h were > 100 mg/L.

Executive summary:

The toxicity of Ethylene cyanohydrin (Batch no.: 1038042701) to the unicellular freshwater green alga Desmodesmus subspicatus was determined according to the principles of OECD 201 at Dr.U.Noack-Laboratorien in 31157 , from September 22 to 25, 2008. The aim of the study was to assess the effects on growth rate and yield production over a period of 72 h in a limit test.
The study was conducted under static conditions with an initial cell density of nominally 2 - 5 x 10³ cells/mL. Six replicates were tested for the limit concentration of 100 mg/L and the control. Environmental conditions were determined to be within the acceptable limits.
The concentrations of Ethylene cyanohydrin were analysed at test start and end via DOC-analysis. All effect levels are given based on the nominal limit test concentration of the test item.