There is no information about biological and pharmacological application of nickel cyanide. But is known, that this substance is used in metallurgy and electroplating. This substance ca irritate and burn eyes and skin on contact; in addition, can irritate a nose, throat and lung, causing coughing.

Cobalt is an essential trace mineral for ruminant animals such as dairy and beef cattle, sheep and goats. Most forages and feedstuffs fed to dairy and beef animals do not contain adequate quantities of cobalt to support the rumen and animal requirements. Cobalt propionate may be a slightly better source of cobalt compared to cobalt carbonate.

There is no information about biological and pharmacological application of cobalt stearate. It is known, that cobalt stearate is a precursor of Co in the synthesis of CoO nanocrystals.

Cobaltous 2-ethylhexanoate (cobalt octoate) is an accelerator in the polyester resins. There have been several reports of allergic contact dermatitis resulting from cobaltous 2-ethylhexanoate. It was demonstrated, that cobalt octoate induced DNA strand breakage in vitro (in human cells), but the damage appeared to be explained by oxidative damage resulting from reactive oxygen species, probably caused by the cobalt cation.

Copper selenite is used as a catalyst in the Kjeldahl digestion of nitrogenous materials.