Coating of biological and/or chemical products (0) involves holding them in a treatment zone (1) which contains a homogenous mist of the coating material together with an inert gas or gas mixture. During coating, the products (0) are retained within the mist. Also claimed is an apparatus with a supply (2) of the coating material, to be fed (3) through a mist generator (5) into the treatment zone (1). A supply (7) of inert gas is linked to the interior of the treatment zone (1).
