Radium dial

Radium paint glowed without being charged, because it was radioactive. The US Nuclear Regulatory Commission states that "Ra-226 was used until the late 1960s/early 1970s in self-luminous paints for watches, aircraft switches, clocks, and instrument dials", and that "The half-life of Ra-226 is 1600 years." The US Environmental Protection Agency states that "Antiques containing radioactive material may continue to emit very low-levels of radiation for thousands of years, if not longer."

The painting was done by hand, and that work is why radium paint is remembered. The Science Museum Group (a museum publication, not a regulator) records that from 1917 women were employed to paint dials for the United States Radium Corporation in New Jersey, the Radium Dial Company in Illinois and the Waterbury Clock Company in Connecticut, and that they "were encouraged to use the lip-pointing technique, pressing the brush between their lips to form a fine point before they dipped it in the paint. Every time this was done, a small amount of radium was ingested." The consequences it records: "Their teeth would ache and eventually fall out... They began to develop severe anaemia. Their bones went brittle. Eventually, jaw necrosis set in."

The litigation changed the law more than it compensated the claimants. Each of the women in the settled case "was awarded $10,000 in damages and $600 per year for the rest of their lives", while "United States Radium would not have to take any legal responsibility". Afterwards, "Lip pointing was banned, and protective equipment was introduced for all workers", and "Legislation was introduced to crack down on commercial radium products and to recognise radium poisoning as a compensable occupational disease."

Such watches still exist and are still regulated. The NRC states that "Any individual intact timepiece containing less than 0.037 megabecquerel... of radioactivity is exempt from regulatory requirements." The Museum of Radiation and Radioactivity, describing a 1927 radium-dial watch in its collection, notes that "Estimates of the average dose to the gonads for someone wearing such a watch ranged from 0.5 to 3 mrem per year." This Codex gives no instruction about what to do with such a watch; it records only what the regulator and the museum state.