Dipotassium oxide

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

9.176 mg/L

Assessment factor:

100

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

2 mg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0.918 mg/L

Assessment factor:

1 000

Extrapolation method:

assessment factor

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

2.2 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

17.75 mg/kg sediment dw

Assessment factor:

10

Extrapolation method:

assessment factor

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

1.78 mg/kg sediment dw

Assessment factor:

10

Extrapolation method:

assessment factor

Hazard for air

Air

Hazard assessment conclusion:

no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

PNEC soil

PNEC value:

85 mg/kg soil dw

Assessment factor:

10

Extrapolation method:

assessment factor

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

no potential for bioaccumulation

Additional information

The high water solubility and low vapour pressure indicate that Potassium oxide will be found predominantly in the aquatic environment. Potassium oxide is present in the environment as potassium and Oxygen ions, which implies that it will not adsorb on particulate matter or surfaces and will not accumulate in living tissues. It is obvious that both potassium and Oxygen ions have a wide natural occurrence (UNEP, 1995).

Atmospheric emissions as Potassium oxide aerosols should be rapidly neutralized by carbon dioxide, or other acids and the salts (e.g. potassium carbonate) will be washed out by rain. For this reason potential atmospheric emissions of Potassium oxide are considered of no concern. Significant emissions to the terrestrial environment are not expected during normal handling and use of Potassium oxide. Small terrestrial emissions will be neutralized by the buffer capacity of the soil. For this reason the environmental assessment can be limited to the aquatic compartment.

Because Potassium oxide does occur in the environment as Potassium and Oxygen a separate environmental assessment of both the potassium and the Oxygen ion is needed.

Oxygen is the most abundant chemical element by mass in the Earth's biosphere, air, sea and land. Oxygen is the third most abundant chemical element in the universe, after hydrogen and helium.

Potassium is essential constituent and one of the most abundant ions in all animal species. In adult humans, the total body potassium is approx. 3.5 mol (135 g). 98 % of this is located intracellular (150 mmol/l), the extracellular potassium concentration is approx. 4 mmol/l.

Both K+ and O- ions are normal constituents of the body fluids. K+ plays an essential role in the human physiology but starts to be toxic at levels exceeding 200 – 250 mg/l. Its concentration in the blood is regulated principally by renal excretion/reabsorption and controlled by an efficient feedback auto-regulation system. An excessive pH of the blood is prevented by the bicarbonate buffer system, respiration and renal compensation mechanisms.

 

Summary of Acute Toxicity for Organism Group and Aquatic algae, cyanobacteria and aquatic plants
Organism Group	Average Acute Toxicity	Acute Toxicity Range
Invertebrates	Not Acutely Toxic	Not Acutely Toxic
Fish	Not Acutely Toxic	Not Acutely Toxic
Molluscs and Amphibians	Not Acutely Toxic	Not Acutely Toxic
Annelida and microorganisms	Not Acutely Toxic	Not Acutely Toxic
Aquatic algae, cyanobacteria and aquatic plants	Not Acutely Toxic	Not Acutely Toxic

Conclusion on classification

The Potassium oxide/ Dipotassium oxide does not meet the criteria to be classified for environmental hazards. Based on the hazard assessment of Alcohols, C16-18 in section 2.1 and 2.2.in IUCLID 5.4., available data for the substance and following the “Guidance on Information Requirement and Chemical Safety Assessment R.10, it is concluded that does not meet the criteria to be classified for environmental hazardsaccording to the criteria described in Directive 67/548 and in the CLP Regulation:

 

Directive 67/548

N; R50 R52 R53 N;R50/53 N;R51/53 R52/53 N;R59

CLP Regulation

H400 Aquatic. Acute 1 Very toxic to aquatic life H413 Aquatic Chronic 4 May cause long lasting harmful effects to aquatic life H400 Aquatic acute 1, Very toxic to aquatic life H410 Aquatic chronic 1 Very toxic to aquatic life with long lasting effects H411 Aquatic Chronic 2 Toxic to aquatic life with long lasting effects H412 Aquatic Chronic 3 Harmful to aquatic life with long lasting effects EUH059 Ozone, Hazardous to the ozone layer

 

 

It is concluded that the substance Potassium oxide/ Dipotassium oxide does not meet the criteria to be classified for environmental hazards.