Mercury vapor lamps are a type of high intensity discharge (HID) lamp that is less efficient than the now widely used metal halide and high pressure sodium lamps.  However, these mercury vapor lamps continue to be used, both in existing fixtures and in some applications where the lower cost of mercury vapor lamps and ballasts are attractive to purchasers, despite their higher energy consumption.

Changes came in 2005, when Congress passed a law, the Energy Policy Act of 2005, also known as “EPAct 2005.”  That legislation banned the sale of mercury vapor ballasts as of 2008.  No new fixtures can be manufactured or imported for sale in the United States. Existing inventories may be sold, but no more will be available after depletion of existing stock.  What’s more, as existing ballasts burn out, they must be replaced with other lamp types.

The National Electrical Manufacturers Association (NEMA) Lighting Systems Division has published a brief paper that addresses the issue of mercury vapor ballasts and related lighting issues.  The paper includes a list of Frequently Asked Questions on the topic.  It may be downloaded at no charge by visiting NEMA’s website at http://www.nema.org/stds/whitepapers/LSD37.cfm

The brief paper outlines the reasons and benefits of the legislation on mercury vapor ballasts, and includes contact information for NEMA experts on the topic.

NEMA is the trade association for the electrical manufacturing industry. It is headquartered in Rosslyn, Va. Its 450 member companies manufacture products used in the generation, transmission and distribution, control, and end-use of electricity. These products are used in utility, medical imaging, industrial, commercial, institutional, and residential applications.

Another useful source of information on this topic: www.mercuryvaporlight.com