Potassium chloride
Potassium chloride for food supplements: grades, EU status under Directive 2002/46/EC and E508, 52.4 % potassium content and label-claim arithmetic.
Technical data
| CAS number | 7447-40-7 |
| EC number | 231-211-8 |
| Molecular formula | ClK |
| Molar mass | 74.55 g/mol |
| E number | E508 |
| Appearance | white crystals or powder |
| Melting point | 770 °C |
| HS code | 3104 20 90 |
Grades and forms
Potassium chloride (KCl) contains 52.4 % potassium by mass, anhydrous basis. To declare 100 mg of potassium per serving you need about 191 mg of potassium chloride. That ratio makes it the most compact potassium source on this site, ahead of potassium citrate at 38.3 %.
Supplement manufacturers buy potassium chloride as white crystals or as a finer powder. Crystals suit dissolving applications such as drink powders. Finer powder blends more evenly with other actives in capsules and tablets.
The grade usually follows your customer’s quality system. Food grade material is specified against the E508 purity criteria in Regulation (EU) No 231/2012. Some brands also require conformity to a pharmacopoeia monograph. Ask for the grade you need in the quote form.
The specification sheet states assay, particle size, loss on drying and contaminant limits. SoleChem sends the specification sheet and the certificate of analysis with its quote, so a bulk potassium chloride lot can be checked against your incoming-goods specification before ordering.
EU regulatory status
Potassium is listed in Annex I of Directive 2002/46/EC, and potassium chloride is listed in Annex II as a permitted source for food supplements. The permitted forms guide explains how the two annexes work together.
Potassium chloride is also authorised as food additive E508 under Regulation (EC) No 1333/2008. Additive use is a separate legal basis with its own conditions. In a supplement where it is the potassium source, it is regulated as a nutrient source under the Directive.
For fortified foods other than supplements, potassium chloride appears in Annex II of Regulation (EC) No 1925/2006.
No harmonised EU maximum amount for potassium in food supplements has been adopted. Member states set their own limits, and some require notification when the product is placed on the market. The maximum levels guide explains how to check each market.
Formulation notes
The label declares potassium, not the salt. The Directive requires the nutrient amount per recommended daily portion. Divide the target by the elemental fraction:
| Potassium per serving | Potassium chloride needed |
|---|---|
| 100 mg | 191 mg |
| 200 mg | 382 mg |
| 500 mg | 954 mg |
The remaining 47.6 % of the mass is chloride. If you also declare chloride, use that figure. The elemental content calculator runs the same arithmetic for any claim.
Potassium chloride is soluble in water and dissolves quickly. This suits drink powders and effervescent tablets. As a neutral salt it does not react with the acid and carbonate system in an effervescent base.
Taste is the main constraint. Potassium chloride tastes salty with a bitter aftertaste, noticeable at higher loadings in dissolved formats. Flavour systems, sweeteners or a partial switch to potassium citrate are the usual responses.
In tablets and capsules, mass is the limiting factor. Several hundred milligrams of potassium per serving quickly fills a capsule or enlarges a tablet. Check fill weight and compression behaviour with the particle size you specify.
How it compares to other forms
| Form | E number | Potassium content | Powder for 100 mg potassium | Handling note |
|---|---|---|---|---|
| Potassium chloride | E508 | 52.4 % | 191 mg | Salty, bitter taste |
| Potassium citrate | E332 | 38.3 % | 261 mg | Cooling, saline taste; deliquescent |
Potassium chloride needs about 27 % less powder than potassium citrate for the same claim. Potassium citrate is deliquescent, so it needs tighter moisture control in storage and processing. The potassium guide covers both forms in more detail.
Other Potassium forms
Compare all Potassium forms →Related minerals & mineral salts
Questions from buyers
How much potassium chloride is needed for a 300 mg potassium claim?
Divide 300 mg by 0.524, which gives about 573 mg of potassium chloride per serving. Add any overage your stability data supports on top of this figure.
What name goes in the ingredient list?
The ingredient list names the substance, potassium chloride, while the nutrient table declares the potassium content. Check the labelling rules of Regulation (EU) No 1169/2011 and Directive 2002/46/EC for the exact presentation in each market.
Can potassium chloride and potassium citrate be combined in one formula?
Yes, both are permitted potassium sources, and blending them is a common way to balance taste and powder mass. Calculate each salt's contribution separately using its own elemental content and add them for the declared total.
Reviewed by Atakan Cilingir, Technical Sales Manager, SoleChem Kimya A.Ş. · Updated October 2026