zOwie Omega Discussion Forum

Here is my original post:

Older models had the letter "T" on either side of the SWISS MADE lettering to indicate that tritium was used in the markers. While long term exposure to tritium by watchmakers may be dangerous, the following link describes why tritium used in older Swatch watches is not dangerous to the wearer.

Superluminova has many benefits over tritium. One is that tritium is a radioactive isotope of hydrogen, and its gradual decay is what causes it to glow. It has a theoretical half life of 12 years, but the other chemicals the tritium is typically mixed with to make watch parts can reduce its life span to as little as 10 years. Though tritium will glow without requiring periodic "recharging" from a light source (as superluminova does), it won't last the life of a high quality watch. By contrast, superluminova does not lose its luminescence with age, since it is simply a luminescent pigment that can be recharged again and again by sunlight or artificial light. So, superluminova is a much better choice from both a safety and a longevity standpoint.