Ferrocyanide is not dangerous. Sodium ferrocyanide is used as an anti-caking agent in table salt. It's considered safe for this use in both the US and the EU, e.g.:
https://ec.europa.eu/food/food-feed-portal/screen/food-addit...
Yes, but as the article points out, the process likes to evolve free cynanide in operation.
Yes, but as the article points out, the process likes to evolve free cynanide in operation.