Safety monitor research foundation (SMRF)  ( an ngo empowering consumers to choose products based on health and safety of ingredients would like to inform consumers not be alarmed by the claims made by certain media publishers on potassium ferrocyanide in Indian salt. Read on to understand more about this food additive.

Potassium ferrocyanide (E 356) is an approved food additive for salt. Its main function is to act as an anti-caking agent. An approved additive with regulatory limits in EU, US, Canada, Australia, India  and many other countries.

The European chemical agency database does not classify E 356 for any health hazard classification. A large number of studies show that this chemical does not cause any harm to the body, specifically it is not carcinogenic or genotoxic. 

Absorption of this chemical in human body is low (0.25–0.42%). Release of cyanide is unlikely due to the strong bonding between iron and each cyanide group.

FSSAI, Food Safety and Standards (Food Products Standards and Food Additives) Regulations, (2011) prescribes a limit of 10mg/ kg of the product as the maximum concentration to be used in salts. In EU countries, ferrocyanides (E 535–538) are authorised food additives with a maximum permissible limits for salts and salt substitutes as 20 mg/kg in the product which includes potassium ferrocyanide. WHO gives average daily intake (ADI) of 0.025 mg/kg bodyweight as limit while European Food Safety Agency (EFSA) limit is 0.03 mg/kg bodyweight per day expressed as ferrocyanide ion. Based on these details the concentration reported for the two brands is within the limits of the recommended usage and consumption. 

SMRF concludes there is no potential harm present to consumers when consuming salts containing potassium ferrocyanide within the prescribed regulatory limits.


1. EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS), (2018). Re-evaluation of sodium ferrocyanide (E 535), potassium ferrocyanide (E 536) and calcium ferrocyanide (E 538) as food additives. EFSA Journal 2018;16(7):5374.

2. Food Safety and Standards (Food Products Standards and Food Additives) Regulations, 2011

3. Evaluations of the Joint FAO/WHO Expert Committee on Food Additives (JECFA).

4. The European chemical agency database.