Looking at the instruction manual for my Trijicon Reflex II, the very first page has the following:
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>WARNING
[radioactivity symbol]
RADIOACTIVE MATERIALS
RADIATION HAZARD
SAFETY PRECAUTIONS
The Reflex Sight contains radioactive material for nighttime illumination. The radiation source is Hydrogen-3, commonly known as tritium. Tritium is an odorless, tasteless, colorless gas that reacts to the human body in the same manner as natural hydrogen. If the Reflex Sight breaks, follow the procedures listed under Safety on page 3. The Reflex sight is regulated under an EXCEMPT LICENCE from the United States Nuclear Regulatory Commission (NRC) held by Trijicon, Inc. Disassambly of the sight is prohibited, except by Trijicon, Inc.[/quote]
And on page 3:
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Tritium is an odorless, tasteless, colorless gas that reacts to the human body in the same manner as natural hydrogen. The body does not easily retain hydrogen or tritium as a gas. However, the oxide, HTO, which is formed by the burning of tritium is 10,000 times more hazerdous. For this reason great care should be taken to avoid flame in the presence of the Reflex Sight with a tritium lamp which is broken or is suspected of leaking.[/quote]
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>After contact with a unit with a broken lamp, a person should wash their hands carefully with soap and water. Do not handle a defective Reflex Sight if you have open cuts or abrasions. Work with a defective unit only in a well ventilated area and avoid inhaling air near the unit.[/quote]