Dipotassium oxide

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

toxicity to microorganisms

Type of information:

other: Published data

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

equivalent or similar to guideline

Guideline:

other: Environment Canada EPS 1/RM/24: biological test method: toxicity test using luminescent bacteria

Principles of method if other than guideline:

Microtox Toxicity Analyser system, Microbics Corporation (Carlsbad CA). Test substance in added to cells suspensions and light readings are measured before and 15 minutes after sample addition. Light loss is proportional to toxicity of the sample, with 50% light loss being defined as the EC50.

GLP compliance:

not specified

Analytical monitoring:

not specified

Details on sampling:

- concentrations: 10,,20,30,40 mg/l
- Sampling method: 4g of test substance was extracted in 20 ml of saline. This sample was weigehed into 2% NaCl to make a 1% (10g/l) solution. This sample was diluted into a concentration range where a normal dose response was observed with LBT

Vehicle:

no

Test organisms (species):

Photobacterium phosphoreum

Details on inoculum:

- Laboratory culture:B-NRRL 11177
- Initial biomass concentration:50g/l

Test type:

other: closed test vial

Water media type:

saltwater

Limit test:

no

Total exposure duration:

15 min

Test temperature:

15°C

pH:

7.8

Dissolved oxygen:

9.1 mg/l

Salinity:

2% NaCl

Nominal and measured concentrations:

nominal concentrations: 10,,20,30,40 mg/l (recovery: 98-103%)

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable):closed
- No. of organisms per vessel:10µl of cell suspension

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : reduction in light

Reference substance (positive control):

yes

Remarks:

sodium hypochlorite

Duration:

15 min

Dose descriptor:

EC50

Effect conc.:

22 mg/L

Nominal / measured:

estimated

Basis for effect:

other: light reduction

Remarks on result:

other: the luminiscent bacteria toxicity test gives following result: 15 minutes EC50 = 22 mg/L for photobacterium phosphoreum

Validity criteria fulfilled:

not specified

Conclusions:

The luminiscent bacteria toxicity test gives following result: 15 minutes EC50 = 22 mg/L for photobacterium phosphoreum.
When Potassium oxide is hydrated is produced Potassium hydroxide. Therefore, the health effects of Potassium hydroxide need to be considered in the assessment of Potassium oxide

Description of key information

The luminiscent bacteria toxicity test gives following result: 15 minutes EC50 = 22 mg/L for photobacterium phosphoreum.

Key value for chemical safety assessment

EC50 for microorganisms:

22 mg/L

EC10 or NOEC for microorganisms:

4.4 mg/L

Additional information

The luminiscent bacteria toxicity test gives following result: 15 minutes EC50 = 22 mg/L for photobacterium phosphoreum.