At a glance
Americium-241 (Am-241) is a manmade metal found in the environment in the form of microscopic dust. As a dust or fine powder, Am-241 can cause certain cancers. Am-241 concentrates in the bones, liver, and muscles, exposing these organs to alpha particles.
Americium-241 properties
Half-life: 432.2 years
Mode of decay: Alpha particles and weak gamma radiation
Chemical properties: Crystalline metal that is solid under normal conditions. Am-241 can be combined with beryllium to produce neutrons.
Appearance: Am-241 is a silver-white metal that is solid under normal conditions.
Use
Am-241 is used in some medical diagnostic devices and in a variety of industrial and commercial devices that measure density and thickness. Tiny Am-241 sources are also present in smoke detectors.
Origin
Am-241 is a manmade metal that is produced from plutonium. Am-241 found in the environment is the result of past nuclear weapons testing.
Form
Am-241 found in the environment is in the form of microscopic dust. Am-241 used in industrial, medical, or commercial devices is in the form of coin-sized metal or plastic discs. The Am-241 source present in a smoke detector is inside a metal cylinder that is about the size of a pencil eraser.
Risks
As a dust or fine powder, Am-241 can cause certain cancers. When Am-241 powder is swallowed, absorbed through a wound, or inhaled it can stay in the body for decades. Am-241 concentrates in the bones, liver, and muscles, exposing these organs to alpha particles.
More information
- Frequently Asked Questions (FAQs) About a Radiation Emergency
- What to Do in Radiation Emergencies
- DTPA (Diethylenetriamine pentaacetate)
- Radiation Dictionary
- Public Health Assessment for Americium (Agency for Toxic Substances and Disease Registry)
- Am-241 Basics (Environmental Protection Agency)
- Radioactive Materials in Smoke Detectors (Environmental Protection Agency)