Undark

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Undark is a trade name for luminous paint made with a mixture of radioactive radium and phosphorous as produced by the U.S. Radium Corporation. It was used primarily in watch dials. Those who applied paint, known as the Radium Girls, died from exposure to excessive radiation. Modern watch dials use tritium, which emits only beta radiation and decays to non-radioactive hydrogen, sealed in borosilicate glass tubes known as Trasers or Gaslights to excite the phosphorous to luminescence.

Contents 1 Other names 2 Further reading 3 See also 4 External links

[edit] Other names

This mixture of radium and phosphorous was used by other companies as well:

• "Luna" was used by Standard Chemical Company
• "Marvelite" was used by Cold Light Manufacturing Company (a subsidiary of the Radium Company of Colorado)

[edit] Further reading

• Clark, Claudia. (1987). Radium Girls: Women and Industrial Health Reform, 1910-1935. University of North Carolina Press. ISBN 0-8078-4640-6.
• Ross Mullner. (1999) Deadly Glow. The Radium Dial Worker Tragedy. American Public Health Association. ISBN 0-8755-3245-4.
• National Council on Radiation Protection and Measurements. "Radiation Exposure from Consumer Products and Miscellaneous Sources. NCRP Report No. 56. 1977.
• Scientific American (Macklis RM, The great radium scandal. Sci.Am. 1993 Aug: 269(2):94-99)

[edit] See also

• Self-powered lighting

[edit] External links

• Roger Russel - Radium Dials
• Damninteresting.com - Undark and the Radium Girls
• orau.org - Radioluminescent paint
• orau.org - Photo gallery of radioluminescent items
• New York Times - "A Glow in the Dark, and a Lesson in Scientific Peril", Denise Grady, October 6, 1998