History of Americium-241

• Americium-241 (Am-241) was first discovered in the midst of World War II as a man-made composite of radioactive metal. The discovery led to the future development of atomic weapons.
  
  

Photoelectric Detectors

• One type of smoke detector, the photoelectric detector, is activated when smoke blocks the flow of light shining into the sensing chamber. There is no radiation in these detectors.
  
  

Ionization Detectors

• Ionization detectors have a small amount of radiation ionizing the air between two metal discs; when smoke enters the chamber, the ionization is disrupted and the alarm sounds.
  
  

Amount of Radioactivity

• One gram of Am-241 supplies 3 million ionization smoke alarms; the actual amount in each alarm is 1 millionth of a curie.
  
  

Potential for Harm

• The radiation level in a smoke detector is so minuscule that it poses no health risk to individuals as long as the detector remains intact. Even if a child somehow swallowed the small radioactive chamber, the product would have little to no adverse radiation effects.