Potassium sulfate

Potassium sulfate (CAS 7778-80-5), also known as potassium sulphate and approved as food additive E515, is a soluble inorganic salt supplying both potassium and sulfur.

Where is Potassium sulfate used?

• Agriculture: preferred potassium fertilizer for chloride-sensitive crops
• Tobacco, citrus, grapes, and vegetables: delivers sulfur alongside potassium without the chloride load of muriate of potash
• Food: firming agent and acidity regulator in processed products
• Pharmaceutical: excipient and mineral source in oral dosage forms and electrolyte preparations
• Industrial chemistry: flux in glass and cement production and catalyst precursor in certain sulfation processes
• In non-agricultural markets it functions as a processing aid, buffering agent, and mineral supplement.
• Commonly applied in drip irrigation systems.
• Beneficial for oil crops such as olive, sunflower, canola, peanut and soybean.

Formulation notes

• For open-field vegetables, application rates of 600-1000 kg per hectare are used.
• Mixing FCC grade with calcium-based fertilizers in concentrated solutions requires care to prevent precipitation.
• When blending FCC grade with phosphorus fertilizers, correct ratios are important, particularly in high-alkalinity soils, to avoid nutrient imbalances.

Typical specification

• Standard agricultural products contain on average 50–52% K2O.
• Average chloride content is 2.3% Cl, corresponding to 5.0% KCl.
• Sold in granular and standard forms.

Regulatory status

• Classified as an EC fertilizer.
• Permitted in organic farming under EEC Reg. 2092/91 and EC Reg. 1073/00.
• To be defined and sold as a fertilizer, a minimum K2O content of 47% and a maximum chloride content of 3% Cl are required by law.
• Registered under the REACH Regulation and manufactured and/or imported in the European Economic Area at ≥ 1,000,000 to < 10,000,000 tonnes per year.

Frequently asked questions about Potassium sulfate

Can it be applied as a top-dressing fertilizer without damaging leaves?

It can be used in top-dressing fertilization without risk of burning the leaves.

Technical content is compiled and updated by the SoleChem product team from public technical sources; the certificate of analysis (COA) governs product-specific specifications.