Sodium iodide

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:

key study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

secondary literature

Justification for type of information:

Data is from secondary literature

Qualifier:

according to guideline

Guideline:

other: Refer below principle

Principles of method if other than guideline:

Toxicity study was conducted to evaluate the effect of test chemical on the cell proliferation of freshwater green algae Scenedesmus quadricauda. Test chemical exposed for 8 days with the green algae.

GLP compliance:

no

Analytical monitoring:

not specified

Vehicle:

not specified

Details on test solutions:

Details on test solutions
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Test substance was dissolved in bi-distilled water, the stock solution neutralized. Two parallel concentration were used in the series which by gradual dilution (factor: 0.5). Control were also used in the study.

Test organisms (species):

other: Scenedesmus quadricauda

Details on test organisms:

Details on test organisms
TEST ORGANISM
- Common name: Green algae
- Method of cultivation: Algae from permanent cultivation were obtain. New breeding of stock cultures in the 10-day cycle added. Inoculation of the test cultures from 10 days old precultures and same culture conditions for parent, preliminary and test organism were maintain throught the study.

Test type:

static

Water media type:

freshwater

Total exposure duration:

8 d

Test temperature:

27 degrees C

pH:

7

Nominal and measured concentrations:

Nominal concentration

Details on test conditions:

Details on test conditions
TEST SYSTEM
- Test vessel: Tubes
- Photoperiod: Continuous light
- Humidity: 50%

Reference substance (positive control):

not specified

Key result

Duration:

8 d

Dose descriptor:

LOEC

Effect conc.:

2 370 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

cell number

Remarks on result:

other: Other details not known

Details on results:

Details on result:
Very low effect were observed on the growth and cell proliferations of green algae after the exposure of test chemical for 8 hrs.

Validity criteria fulfilled:

not specified

Conclusions:

Based on the effect observed on the cell proliferation rate of green algae Scenedesmus quadricauda after 8 days of exposure, the LOEC was observed at 2370 mg/l.

Executive summary:

Toxicity study was conducted to evaluate the effect of test chemical on the cell proliferation of freshwater green algae Scenedesmus quadricauda. Test chemical exposed for 8 days with the green algae. Test performed under the static system by using 10 days old culture. Test substance was dissolved in bi-distilled water, the stock solution neutralized. Two parallel concentration were used in the series which by gradual dilution (factor: 0.5). Control were also used in the study. Algae from permanent cultivation were obtain. New breeding of stock cultures in the 10-day cycle added. Inoculation of the test cultures from 10 days old precultures and same culture conditions for parent, preliminary and test organism were maintain throughout the study. From each inoculated batch, three 10 ml culture tubes were used and one tube per control. Shake the test cultures once a day. Cell density determination at the end of the test photometric at 578 nm. Very low effect were observed on the growth and cell proliferations of green algae after the exposure of test chemical for 8 hrs. Based on the effect observed on the cell proliferation rate of green algae Scenedesmus quadricauda after 8 days of exposure, the LOEC was observed at 2370 mg/l. based on the LOEC, chemical consider to be nontoxic and not classified as per the CLP classification criteria.

Description of key information

Toxicity study was conducted to evaluate the effect of test chemical on the cell proliferation of freshwater green algae Scenedesmus quadricauda. Test chemical exposed for 8 days with the green algae. Test performed under the static system by using 10 days old culture. Test substance was dissolved in bi-distilled water, the stock solution neutralized. Two parallel concentration were used in the series which by gradual dilution (factor: 0.5). Control were also used in the study. Algae from permanent cultivation were obtain. New breeding of stock cultures in the 10-day cycle added. Inoculation of the test cultures from 10 days old precultures and same culture conditions for parent, preliminary and test organism were maintain throughout the study. From each inoculated batch, three 10 ml culture tubes were used and one tube per control. Shake the test cultures once a day. Cell density determination at the end of the test photometric at 578 nm. Very low effect were observed on the growth and cell proliferations of green algae after the exposure of test chemical for 8 hrs. Based on the effect observed on the cell proliferation rate of green algae Scenedesmus quadricauda after 8 days of exposure, the LOEC was observed at 2370 mg/l. based on the LOEC, chemical consider to be nontoxic and not classified as per the CLP classification criteria.

Key value for chemical safety assessment

EC50 for freshwater algae:

2 370 mg/L

Additional information

Various short term studies available for the test chemical were reviewed to determine the toxic nature of test chemical on the growth of aquatic algae and cyanobacteria. The studies are as mentioned below:

 

Toxicity study was conducted to evaluate the effect of test chemical on the cell proliferation of freshwater green algae Scenedesmus quadricauda. Test chemical exposed for 8 days with the green algae. Test performed under the static system by using 10 days old culture. Test substance was dissolved in bi-distilled water, the stock solution neutralized. Two parallel concentration were used in the series which by gradual dilution (factor: 0.5). Control were also used in the study. Algae from permanent cultivation were obtain. New breeding of stock cultures in the 10-day cycle added. Inoculation of the test cultures from 10 days old precultures and same culture conditions for parent, preliminary and test organism were maintain throughout the study. From each inoculated batch, three 10 ml culture tubes were used and one tube per control. Shake the test cultures once a day. Cell density determination at the end of the test photometric at 578 nm. Very low effect were observed on the growth and cell proliferations of green algae after the exposure of test chemical for 8 hrs. Based on the effect observed on the cell proliferation rate of green algae Scenedesmus quadricauda after 8 days of exposure, the LOEC was observed at 2370 mg/l. based on the LOEC, chemical consider to be nontoxic and not classified as per the CLP classification criteria.

 

First key study was supported by the second study from secondary source. Study was designed to evaluate the effect of test chemical on the growth of algae. The lowest observed effect concentration (LOEC) value was observed at 2370 mg/L in Scenedesmus quadricauda (Green Algae) in a aquatic toxicity study conducted with test chemical on the basis of Population growth rate. Thus chemical consider to be not classified as per the CLP classification criteria.

 

Similar study was conducted to determine the effect of test chemical on the growth of algae. Test conducted under the static system. The low observed effect concentration (LOEC) value observed is 66 mg/l in Microcystis aeruginosa (Blue-Green Algae) in a aquatic toxicity study conducted with test chemical on the basis of Population growth rate. As low effect were observed on the growth of algae, EC50 was not obtain. Thus on that basis, chemical not consider to be classified as toxic.

 

Based on the overall data from secondary sources and, it can be concluded that the substance is considered to be not toxic to aquatic environment (algae and cyanobacteria) and cannot be classified as toxic as per the criteria mentioned in CLP regulation.