CAS ID#: 7440-35-9

Affected Organ Systems: Developmental (effects while organs are developing), Hepatic (Liver), Musculoskeletal (Muscles and Skeleton), Renal (Urinary System or Kidneys), Respiratory (From the Nose to the Lungs)

Cancer Classification:  Please contact NTP, IARC, or EPA with questions on cancer and cancer classification.

Chemical Classification: None

Summary: Americium is a man-made radioactive chemical. Americium has no naturally occurring or stable isotopes. Two important isotopes of americium are americium 241 (241Am) (read as americium two-forty-one) and 243Am. Both isotopes have the same chemical behavior in the environment and the same chemical effects on your body. 241Americium is used in ionization smoke detectors. There is no broad commercial use for 243Am. Nuclear reactors, nuclear explosions, or the radioactive transformation of plutonium can produce both 241Am and 243Am. These isotopes transform by giving off alpha radiation and turning into radionuclides of other elements. The half-life of a radioactive material is the time it takes for half of the material to give off its radiation. The half-life of 241Am is 432 years and that of 243Am is 7,370years.

Community Members
Community Members

ToxFAQs - Fact sheet that answers the most frequently asked questions about a contaminant and its health effects.

Public Health Statement - Summary about a hazardous substance taken from Chapter One of its respective ATSDR Toxicological Profile.

Toxicological and Health Professionals
Toxicological and Health Professionals

Toxicological Profile - Succinctly characterizes the toxicologic and adverse health effects information for a hazardous substance.

Priority List of Hazardous Substances - Prioritization of substances based on a combination of their frequency, toxicity, and potential for human exposure at National Priorities List (NPL) sites.

Minimal Risk Levels (MRL) - The MRL is an estimate of the daily human exposure to a hazardous substance that is likely to be without appreciable risk of adverse, non-cancer health effects over a specified duration of exposure. The information in this MRL serves as a screening tool to help public health professionals decide where to look more closely to evaluate possible risk of adverse health effects from human exposure.

Page last reviewed: February 10, 2021