Potassium ferrocyanide, often referred to as yellow prussiate of potash or simply K4[Fe(CN)6], is a coordination compound. It appears as yellow crystals or a yellow powder and is highly soluble in water. This compound is widely used in various applications, including the food industry. It is classified as a food additive with the European food additive number E536.

In the food industry, potassium ferrocyanide is primarily used as an anti-caking agent. It prevents the formation of lumps in table salt, which can occur due to moisture absorption. The compound is added to salt to maintain its free-flowing properties, ensuring that consumers can easily sprinkle or pour the salt. Potassium ferrocyanide is considered safe for consumption when used within regulatory limits, and it has been thoroughly evaluated for its safety in food products.