Selenium powder is a non-metallic chemical element. It resembles sulfur and tellurium in chemical activity and physical properties. Selenium appears in a number of allotropic forms: the most popular forms are a red amorphous powder, a red crystalline material, and a gray crystalline metal like form called metallic selenium. Selenium powder is unaffected by water however it burns in air and it can easily dissolve in concentrated alkalis and nitric acid.  

Selenium powder exhibits good photovoltaic and photoconductive properties, and it is utilized extensively in electronics, for instance, photocells, light meters, and solar cells. The use of selenium is in the glass industry: selenium is applied to remove the colour from glass, to give a red color to enamels and glasses.

Sodium selenite is utilized for animal feeds and food supplements. Selenium can also find applications in photocopying, in the toning of photographs and its artistic use is to intensify and extend the tonal range of black and white photographic images. Other uses of selenium are in metal alloys for example lead plates are used in storage batteries and in rectifiers to convert AC current in DC current.

Selenium powder is employed to enhance the abrasion resistance in vulcanized rubbers and some selenium compounds are to anti-dandruff shampoos. Selenium is employed in solar cells with copper, indium, and gallium. Small amounts of organoselenium compounds have been used to alter the catalysts used for the vulcanization for the production of rubber.

Selenium powder is useful in photocells and light meters and also use as a photoconductor in plain-paper copiers. It is also employed as a gamma source in industrial radiography and it is also used in lithium batteries for energy storage. Amorphous selenium thin films have found application as photoconductors in flat panel X-ray detectors.