As explained in the February 24, 2023 blog post, there remain lamps and light sources which contain mercury but are still exempt from the RoHS Directive. With its decades of experience and innovation, Nichia wants to contribute to the realization of a mercury-free society by promoting alternative light sources, specifically LEDs and Laser Diodes which do not contain mercury.

The table below summarizes light sources which are exempt from the RoHS Directive and whose manufacture and sale are permitted even though they contain mercury. In fact, some items are classified more in details based on the amount of contained mercury, but the items listed in this table cover most of what is needed when considering alternative technologies.

These can be broadly classified as follows: high pressure sodium lamps which emit the nostalgic color of gaslight lamps and are used in street lighting and green house lighting; low pressure mercury lamps often used as germicidal lamps which emit ultraviolet light for sterilization; mercury short arc lamps used for photolithography; medium pressure mercury lamps used for paint curing; and projector lamps used for high-output projectors. Nichia's major goal is to promote the realization of a mercury-free society by replacing these lamps with LEDs and LDs.

From the next blog post, Nichia will provide specific examples of how LEDs/LDs can be alternative technologies.