Acid-proof stainless steel

This is the highest level of protection offered by Fagerhult and is normally associated with luminaires designed for external environments, such as industrial activities which handle acids, salts and other corrosive substances. An installation that is close to the coast can also put a strain on normal light fixtures. Acid-proof stainless steel can still corrode if the surface becomes coated in dirt and acid is not able to penetrate down to the surface of the material.

Usually, acid-proof stainless steel is combined with other equally hardy materials such as glass rather than plastic so as to ensure the best possible encapsulation.