Potassium carbonate
This Product Safety Summary is intended to provide a general overview of the chemical substance in
the context of ICCA Global Product Strategy. The information in the Summary is basic information
and is not intended to provide emergency response, medical or treatment information. In-depth
safety and health information can be found in the (extended) Safety Data Sheet (e)SDS for the
chemical substance.
General Statement
Potassium carbonate is a white solid at room temperature and is generated from potassium
hydroxide by reaction with carbon dioxide. It has a long history, being the primary component of
Potash, which has been used from early history in textile bleaching, glass manufacture and soap
production. It dissolves in water to give an alkaline (basic) solution. It is used in large quantities in a
variety of industries.
Chemical Identity
Name: potassium carbonate
Synonyms: potash, pearl ash
CAS number: 584-08-7
Molecular formula: K2CO3
Use and Applications
Potassium carbonate has many different functions and uses. It is primarily used in large industry, in
the manufacture of chemicals, fertilisers, soap and glass. It is also used as a drying agent (it removes
water from air) and to reduce acidity when producing mead or wine. It is an ingredient in many
formulations for consumer use, like disinfectants, ink and toners, paints and cleaning products
(among others).
Physical/Chemical Properties
Pure potassium carbonate is a solid at room temperature. The appearance of the substance and
some physicochemical properties are mentioned in the table below.
Physical state
Colour
Density
Melting temperature
Boiling temperature
Molecular weight
Water solubility
Solid (powder)
White
2.43 g/cm3 (19 °C)
891 °C
The substance decomposes at high
temperature
138.2 g/mol
Very soluble
Potassium carbonate dissociates completely in water into potassium (K+) and carbonate ions (CO32-).
The dissolution/dissociation in water is exothermic (releases heat), so a vigorous reaction can occur
when potassium carbonate is added to water. The vapour pressure of the substance is very low and
a melting point cannot be determined, as the substance decomposes at high temperature.
Human Health Safety Assessment
Potassium carbonate is a hygroscopic substance and therefore solid potassium carbonate slowly
absorbs water from the air. Exposure to the pure substance can lead to skin and eye irritation, so
contact with skin and eyes should be avoided.
Sodium carbonate will dissociate into its constituent ions and will not be systemically available in the
body. As a consequence, potassium carbonate will not cause systemic toxicity in any organs,
including the reproductive system. Furthermore, potassium carbonate is not carcinogenic or
genotoxic.
Environmental Safety Assessment
Potassium carbonate has a low hazard to the environment. Potassium and carbonate ions are
naturally found widely in the environment, and thus the substance itself will have little impact.
Carbonate ions leads to a rise in pH of water (ie it becomes more basic), but this generally does not
occur to a large degree. However, the pH of waste water should be checked to ensure it is not to
high.
Because potassium carbonate is natural in the environment, the substance is not persistent and it
will not accumulate in organisms or in the food chain.
Exposure
Consumer
Potassium carbonate is widely used in consumer products. Generally it is not a concern for human
exposure, and it is also used in food and drink products. The instructions on the label of all products
should be read and followed carefully to ensure safe use.
Worker
Because potassium carbonate has many different applications, it is extensively used in the industry
and also by other professionals.
As mentioned above in the section on consumer exposure, skin contact for products or solutions
with a low potassium carbonate concentration is generally not a concern due to low toxicity.
The main concern for industrial uses of potassium carbonate is the formation of dust, which can be
breathed in by workers and possibly cause irritation. In order to avoid this, measures should be
taken to avoid dust formation and exposure. Appropriate personal protective equipment should be
used and workers should consult the manufacturer’s Safety Data Sheet to obtain specific advice.
Environment
The only possible hazard of potassium carbonate to the environment is caused by a raised alkalinity
due to the carbonate ion (pH effect). Because there is legislation for the pH control of waste water
and surface water in many countries, a significant pH increase of the aquatic environment (e.g. a
river or a sea) is not expected due to the manufacture or use of potassium carbonate. Furthermore
it is relatively easy to adapt the pH of waste water (to neutralize the pH of water) and therefore
significant effects of potassium carbonate on the aquatic environment are not expected.
Emissions to air are also not a concern because potassium carbonate has a low vapour pressure, and
dust will be rapidly removed from air.
Regulatory Information
The substance was reviewed in 2007 under the OECD (Organisation for Economic Co-operation and
Development) high production volume (HPV) chemicals program. This is a global program to
evaluate the hazards of chemicals.
In 2010 potassium carbonate has been registered under the European Union REACH Regulation
EC/1907/2006 and the substance was found to be safe for the uses identified.
The results of all these 2 regulatory programs are available via internet.
Classification and Labelling
The substance is subject to harmonised classification and labelling under the EU Classification
Labelling and Packaging (CLP) Regulation EC/1272/2008. The main elements are given hereafter:
Skin irritation
category 2
H315
Causes skin irritation
Eye irritation
H319
Causes serious eye irritation
category 2
STOT single
H335
May cause respiratory irritation
exposure 3
The hazard statements above are applicable for a concentration in chemical products of 3% w/w or
higher. For concentrations below 3 % w/w the substance is not classified.
Conclusion
Potassium carbonate is used in large amounts in industry and consumer products. It can cause some
irritation at high concentrations. However, no effects on human health are expected when humans
are in contact with low concentrations or amounts of the substance. The substance is neutralised in
the environment and therefore it is not persistent. Furthermore it does not accumulate in
organisms. Waste water which contains potassium carbonate should be neutralised (pH control)
before it is discharged to the environment. In this way effects on the aquatic environment (for
example organisms living in a river) are prevented. Use of this substance has shown to be safe by
careful use and following provided instructions
Contact Information within Company
For further information on this substance or product safety summaries in general, please contact:
Xxxxx Xxxxx at xxxxxx@xxxxx.com or visit our website at www.xxxx.com.
Euro Chlor (www.eurochlor.org), the European chlor-alkali manufacturers association is a useful
repository of information regarding potassium carbonate and can be contacted at
eurochlor@cefic.be.
Additional information on the ICCA global product strategy can be found here:
http://www.icca-chem.org/en/Home/ICCA-initiatives/global-product-strategy/
Date of Issue
xx/xx/xxxx
Revised
xx/xx/xxxx