Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Stability

 

Phototransformation in air

  

Dipotassium oxide/ Potassium oxide has low vapor pressure (3.03E-014 Pa) indicating significant amounts of Dipotassium oxide/ Potassium oxide are unlikely to be present in the atmosphere for photodegradation.

If released to air, a vapor pressure of 2.27E-016 mm Hg  at 25 deg C (2.27E-016 mm Hg is equivalent to a vapour pressure of 3.03E-014 Pa) indicates significant amounts of Dipotassium oxide/ Potassium oxide are unlikely to be present in the atmosphere for photodegradation and therefore Dipotassium oxide/ Potassium oxide is not expected to be susceptible to direct photolysis by sunlight. 

 

   

Phototransformation in water

 

If released into water, Dipotassium oxide/ Potassium oxide is not expected to adsorb to suspended solids and sediment based upon the estimated Koc value of 13.22 L/kg. Volatilization from water surfaces is not expected to be an important fate process based upon this compound's estimated Henry's Law constant is 2.814E-023 atm-m3/mole (2.851E-018 Pa-m3/mole).

On this basis phototransformation in water is not expected .

Therefore testing for Phototransformation in water does not need to be performed.

 

Phototransformation in soil

If released to soil, Dipotassium oxide/Potassium oxide is expected to have very high mobility based upon an estimated Koc of 13.22. Volatilization from moist soil surfaces is not expected to be an important fate process.

    

Therefore testing for Phototransformation in soils does not need to be performed. 

Hydrolysis

 According to “ANNEX VIII- STANDARD INFORMATION REQUIREMENTS FOR SUBSTANCES MANUFACTURED OR IMPORTED IN QUANTITIES OF 10 TONNES OR MORE , study for Hydrolysis as a function of pH does not need to be conducted if:

-the substance is ready biodegradable.

 As Dipotassium oxide/Potassium oxide is ready biodegradable a Hydrolysis study does not need to be conducted.

Hydrolysis is not expected to be an important environmental fate process since this compound lacks functional groups that hydrolyze under environmental conditions.

Hydrolysis is a chemical reaction during which molecules of water (H2O) are split into hydrogen cations (H+, conventionally referred to as protons) and hydroxide anions (OH−) in the process of a chemical mechanism).

Potassium oxide is a basic oxide and reacts with water violently to produce the caustic potassium hydroxide

When water is added to Potassium oxide, KOH is produced.

K2O+H2O→KOH

On this basis, Potassium oxide does not have a potential for Hydrolysis and Potassium ion will not hydrolise.