Potassium 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:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data is from peer reviewed journal

Justification for type of information:

Data is from peer reviewed journal

Qualifier:

according to guideline

Guideline:

other: Refer below principle

Principles of method if other than guideline:

To evaluate toxicity of test chemical on the growth of Dunaliella salina.

GLP compliance:

no

Analytical monitoring:

not specified

Vehicle:

no

Test organisms (species):

Dunaliella salina

Details on test organisms:

Serial concentrations of test chemical were supplemented into the modified medium for the culture of Dunaliella salina.

Test type:

not specified

Water media type:

saltwater

Total exposure duration:

10 d

Hardness:

no data

Test temperature:

25 deg C

pH:

no data

Dissolved oxygen:

above 45% saturation.

Salinity:

no data

Details on test conditions:

The inocula, each containing 3 × 10(4) alga cells, were added to 10mL of the corresponding media and incubated in an oscillator shaker at a rate of 150 rpm under light irradiation of 81.04μmolm−2 s−1 and a 12 h/12 h light/dark cycle.

Reference substance (positive control):

not specified

Key result

Duration:

10 d

Dose descriptor:

other: Minimum Inhibitory Concentration (MIC100)

Effect conc.:

356.8 mg/L

Nominal / measured:

not specified

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: Other details not known

Details on results:

The growth of algae was determined by counting the number of cells using a haemacytometer. The minimum concentration of test chemical that inhibited growth was designated as MIC100.

Validity criteria fulfilled:

not specified

Conclusions:

Minimum Inhibitory Concentration (MIC100) value of test chemical in green algae (Dunaliella salina) in a 10 days. study on growth effect was determine to be 356.8 mg/L.Thus considering CLP Criteria for aquatic classification of the substance, it is concluded that test chemical does not exhibit toxicity to green algae (Dunaliella salina).

Executive summary:

To evaluate toxicity of test chemical on the growth of Dunaliella salina. Saltwater Dunaliella salina were used as a test organism which exposed for the 10 days of incubation. Serial concentrations of test chemical were supplemented into the modified medium for the culture of Dunaliella salina. The inocula, each containing 3 × 10(4) alga cells, were added to 10mL of the corresponding media and incubated in an oscillator shaker at a rate of 150 rpm under light irradiation of 81.04μmolm−2 s−1 and a 12 h/12 h light/dark cycle. Minimum Inhibitory Concentration (MIC100) value of test chemical in green algae (Dunaliella salina) in a 10 days. study on growth effect was determine to be 356.8 mg/L.Thus considering CLP Criteria for aquatic classification of the substance, it is concluded that test chemical does not exhibit toxicity to green algae (Dunaliella salina).

Description of key information

To evaluate toxicity of test chemical on the growth of Dunaliella salina. Saltwater Dunaliella salina were used as a test organism which exposed for the 10 days of incubation. Serial concentrations of test chemical were supplemented into the modified medium for the culture of Dunaliella salina. The inocula, each containing 3 × 10000 alga cells, were added to 10mL of the corresponding media and incubated in an oscillator shaker at a rate of 150 rpm under light irradiation of 81.04μmolm−2 s−1 and a 12 h/12 h light/dark cycle. Minimum Inhibitory Concentration (MIC100) value of test chemical in green algae (Dunaliella salina) in a 10 days. study on growth effect was determine to be 356.8 mg/L. Thus considering CLP Criteria for aquatic classification of the substance, it is concluded that test chemical does not exhibit toxicity to green algae (Dunaliella salina).

Key value for chemical safety assessment

EC50 for freshwater algae:

356.8 mg/L

Additional information

Data available for the test chemicals, study has been reviewed to determine the short term toxicity on growth of algae and cyanobacteria of the test chemical. The studies are as mentioned below:

To evaluate toxicity of test chemical on the growth of Dunaliella salina. Saltwater Dunaliella salina were used as a test organism which exposed for the 10 days of incubation. Serial concentrations of test chemical were supplemented into the modified medium for the culture of Dunaliella salina. The inocula, each containing 3 × 10(4) alga cells, were added to 10mL of the corresponding media and incubated in an oscillator shaker at a rate of 150 rpm under light irradiation of 81.04μmolm−2 s−1 and a 12 h/12 h light/dark cycle. Minimum Inhibitory Concentration (MIC100) value of test chemical in green algae (Dunaliella salina) in a 10 days. study on growth effect was determine to be 356.8 mg/L.Thus considering CLP Criteria for aquatic classification of the substance, it is concluded that test chemical does not exhibit toxicity to green algae (Dunaliella salina).

 

In the second study the effects of chemical on the growth and metabolite accumulation of Chlorella sp. were investigated to assess its possible application to the mass culture of the two diatoms in open environment, extensive systems. Test conducted under the static system for 10 days brackish water Chlorella sp. maintain under the proper conditions of temperature and pH. Serial concentrations of test chemical were supplemented into the f/2 medium for Chlorella sp. At concentrations >700 mg/l, the growth of Chlorella sp. was inhibited. Minimum Inhibitory Concentration (MIC100) of test chemical in green algae (Chlorella sp.) in a 10 days study on growth effect was observed to be 696.2 ± 9.4 mg/L. Thus considering CLP Criteria for aquatic classification of the substance, it is concluded that the test chemical does not exhibit toxicity to green algae (Chlorella sp.) and thus not classified.

 

Above results were supported by another study from peer reviewed journal. Aim of this study was to determine the effect of test chemical on the growth of Cryptomonas sp. Test conducted under the static system for the total exposure period of 10 days. Minimum Inhibitory Concentration (MIC100) value of test chemical in green algae (Cryptomonas sp.) in a 10 days study on growth effect was determine to be 475.9 ± 10.3 mg/L. Thus considering CLP Criteria for aquatic classification of the substance, it is concluded that the test chemical does not exhibit toxicity to green algae (Cryptomonas sp) and thus not classified as per the classification criteria.

 

Thus based on the above results, chemical consider to be nontoxic and not classified as per the CLP classification criteria.