Iron(II) fumarate

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Experimental test result performed using standard test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

The stock solution 100 mg/l was prepared in OECD growth medium. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample with OECD growth medium ans inoculum culture.

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: Green algae
- Strain: 86.81 SAG
- Source (laboratory, culture collection): Institute of botany of the ASCR
- Initial biomass concentration: 5x10(3) cells /ml
- Method of cultivation: No data available

ACCLIMATION - No data available
- Acclimation period:
- Culturing media and conditions (same as test or not):
- Any deformed or abnormal cells observed:

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

23±2°C

pH:

Test at highest concentration 100 mg/l: 6.6 changes to 8 during test
Control: 8.1 changes to 8.2 during test

Nominal and measured concentrations:

Nominal test concentrations: 0, 12, 20, 35, 59 and 100 mg/l, respectively

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 ml Glass vessel
- Type (delete if not applicable): closed (with air permeable stopper)
- Sample volume: 15 ml
- Initial cells density: 5x10e3 cells/ml
- No. of vessels per concentration (replicates): 3

GROWTH MEDIUM
- Standard medium used: yes

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: Continuous
- Light intensity and quality: 6000-8000 lx

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: microscope with counting chamber Cyrus I or electronic particle counter.
- Other: ErC50 was calculated using non-linear regression by the software Prism 4.0

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (K2Cr2O7)

Key result

Duration:

72 h

Dose descriptor:

other: ErC50

Effect conc.:

56.4 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95 % CI 45.6 - 69.8 mg/l

Results with reference substance (positive control):

- Results with reference substance valid
- ErC50: 0.75 mg/L (24 hours)

Reported statistics and error estimates:

ErC50 was calculated using non linear regression by the software Prism 4.0

Validity criteria fulfilled:

yes

Conclusions:

Based on the growth rate inhibition of green algae Desmodesmus subspicatus (previous name: Scenedesmus subspicatus) due to the exposure of test chemical for 72 hours, the ErC50 value was determined to be 56.4 mg/l.

Executive summary:

Principle of this study was to determine the effect of test chemical on the growth of green algae when exposed for 72 hours. Test conducted according to the OECD Guideline 201 (Alga, Growth Inhibition Test). The stock solution 100 mg/l was prepared in OECD growth medium. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture. Various nominal concentrations 0, 12, 20, 35, 59 and 100 mg/l, respectively were used in the study. 50 ml Glass vessel filled with 15 ml of test solution were used in the study, in which 5x10e3 cells/ml were added. Test performed using 3 replicates. Temperature maintained at 23±2°C and pH value 6.6 changes change to 8 during test in sample, whereas for control 8.1 changes to 8.2 during test. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0. Effect on the growth of algae was determine after an exposure period of 72 hrs. Based on the growth rate inhibition of green algae Desmodesmus subspicatus (previous name: Scenedesmus subspicatus) due to the exposure of test chemical for 72 hours, the ErC50 value was determined to be 56.4 mg/l with 95 % CI of 45.6 to 69.8 mg/l. Thus, based on the ErC50 value, test chemical considered to be toxic and classified in aquatic chronic category 3 as per the CLP classification criteria.

Description of key information

Principle of this study was to determine the effect of test chemical on the growth of green algae when exposed for 72 hours. Test conducted according to the OECD Guideline 201 (Alga, Growth Inhibition Test). The stock solution 100 mg/l was prepared in OECD growth medium. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture. Various nominal concentrations 0, 12, 20, 35, 59 and 100 mg/l, respectively were used in the study. 50 ml Glass vessel filled with 15 ml of test solution were used in the study, in which 5x10e3 cells/ml were added. Test performed using 3 replicates. Temperature maintained at 23±2°C and pH value 6.6 changes change to 8 during test in sample, whereas for control 8.1 changes to 8.2 during test. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0. Effect on the growth of algae was determine after an exposure period of 72 hrs. Based on the growth rate inhibition of green algae Desmodesmus subspicatus (previous name: Scenedesmus subspicatus) due to the exposure of test chemical for 72 hours, the ErC50 value was determined to be 56.4 mg/l with 95 % CI of 45.6 to 69.8 mg/l. Thus, based on the ErC50 value, test chemical considered to be toxic and classified in aquatic chronic category 3 as per the CLP classification criteria. But as the test chemical was readily biodegradable in water, thus consider to be nontoxic and not classified as per the CLP classification criteria.

Key value for chemical safety assessment

EC50 for freshwater algae:

56.4 mg/L

Additional information

Summarized result from the various experimental sources for the determination of effect of test chemical and structurally and functionally similar read across chemicals on the algae are as mentioned below:

Principle of this study was to determine the effect of test chemical on the growth of green algae when exposed for 72 hours. Test conducted according to the OECD Guideline 201 (Alga, Growth Inhibition Test). The stock solution 100 mg/l was prepared in OECD growth medium. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture. Various nominal concentrations 0, 12, 20, 35, 59 and 100 mg/l, respectively were used in the study. 50 ml Glass vessel filled with 15 ml of test solution were used in the study, in which 5x10e3 cells/ml were added. Test performed using 3 replicates. Temperature maintained at 23±2°C and pH value 6.6 changes change to 8 during test in sample, whereas for control 8.1 changes to 8.2 during test. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0. Effect on the growth of algae was determine after an exposure period of 72 hrs. Based on the growth rate inhibition of green algae Desmodesmus subspicatus (previous name: Scenedesmus subspicatus) due to the exposure of test chemical for 72 hours, the ErC50 value was determined to be 56.4 mg/l with 95 % CI of 45.6 to 69.8 mg/l. Thus, based on the ErC50 value, test chemical considered to be toxic and classified in aquatic chronic category 3 as per the CLP classification criteria. But as the test chemical was readily biodegradable in water, thus consider to be nontoxic and not classified as per the CLP classification criteria.

 

Above experimental data further supported by the second study from peer authoritative databases. Principle of this study was to determine the effect of test chemical on the growth rate inhibition of green algae. The study was performed according to other guideline UBA algal growth inhibition test. Scenedesmus subspicatus was used as a test organism and exposed for 72 hours with test chemical. Test conducted under the static system. Based on the growth rate inhibition of test organism Scenedesmus subspicatus, the 72 hours EC10, EC50 and EC90 value was determined to be 32, 41 and 49 mg/l, respectively. On the basis of EC50 value, it can be concluded that the substance can be considered to be toxic to aquatic organisms and classified in aquatic chronic category 3. Since the test chemical is readily biodegradable in nature, thus, chemical can be considered as non-toxic to Scenedesmus subspicatus at environmentally relevant concentrations and can be considered to be not-classified as per the CLP classification criteria.

 

Similar study was conducted to determine the toxicity of test chemical on the population growth rate inhibition of green algae. Test conducted on freshwater Haematococcus pluvialis. Based on the population growth rate inhibition of green algae Haematococcus pluvialis due to the test chemical exposure, the EC50 value was determined to be 125 mg/l. Thus, on the basis of EC50 value, test chemical considers to be nontoxic and not classified as per the CLP classification criteria.

 

Hence, considering above all studies from different sources, it was concluded that the test chemical was nontoxic and not classified as per the CLP classification criteria.