Dipotassium oxide

Endpoint summary

Description of key information

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.
Based on the available literature, there is a risk for accidental and intentional exposure to solid Potassium oxide (When Potassium oxide is hydrated is produced Potassium hydroxide.) or to irritating or corrosive solutions of Potassium oxide. Most of the ingestion accidents seem to be related with children and seem to occur at home. Accidental skin and eye exposure seems to be less frequently reported than ingestion in the medical literature.

Additional information

Environmental Exposure and Fate

 

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 andOxygenions, 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 andOxygenions 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 andOxygena separate environmental assessment of both the potassium and theOxygenion 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.

 

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.

 

 

Exposure Potential

Human Health

 

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.

Potassium chloride (KCl)is the most common source of Potassium oxide (K2O).Therefore, the health effects ofpotassiumchlorideneed to be considered in the assessment of Potassium oxide.

Solid Potassium oxide (Potassium hydroxide as a surrogate for Potassium oxide) is corrosive. Depending on the concentration, solutions of Potassium oxide are non-irritating, irritating or corrosive and they cause direct local effects on the skin and eyes. Systemic effects are not to be expected. Solutions with concentrations higher than 2% are corrosive, while concentrations of about 0.5 to about 2.0 % are irritating.

Based on the data with other potassium compounds No gene mutations were reported in bacterial tests, with and without metabolic activation.

 

Based on the data with other potassium compounds, it could be concluded that potassium has no or a negligible contribution to the toxicity at lethal dose levels of Potassium oxide.

With KCl, the NOEL in rats for repeated dose toxicity is > 1820 mg/kg bw/day, and > 88-108 mg/kg bw/day in women, and for reproduction/developmental toxicity, > 235 and > 310 mg/kg bw/day for, respectively, mice and rats.

With K2CO3, the teratogenic NOEL values could be established as > 290 mg/kg bw/day for mice, and > 180 mg/kg bw/day for rats.

 

Under normal handling and use conditions (non-irritating) neither the concentration of potassium in the blood nor the pH of the blood will be increased above normal limits and therefore Potassium oxide is not expected to cause systemically toxic levels in the blood.

 

Based on the data with other potassium compounds No evidence of treatment -related carcinogenicity was observed in rats administered up to 1820 mg KCl/kg body weight/day through the food in a 2 year study.

Based on the data with other potassium compounds in developmental study revealed No foetotoxic or teratogenic effects of KCl in doses up to 235 mg/kg/day (mice) and 310 mg/kg/day (rats). No fertility study has been located.

 

Anin vitro genetic toxicity test indicated no evidence for a mutagenic activity. No mutagenic activity was found for the related substances or KCl and K2CO3 (in vitro).

 

Dust formation is unlikely because of the hygroscopic properties. Furthermore Potassium oxide has a negligible vapour pressure and therefore dust and vapour exposure are not expected.

 

Because Potassium oxide does occur in the environment as Potassium andOxygena separate environmental assessment of both the potassium and theOxygenion 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.

 

Based on the available literature, there is a risk for accidental and intentional exposure to solid Potassium oxide (WhenPotassium oxide is hydrated is produced Potassium hydroxide.) or to irritating or corrosive solutions of Potassium oxide. Most of the ingestion accidents seem to be related with children and seem to occur at home. Accidental skin and eye exposure seems to be less frequently reported than ingestion in the medical literature.