Are smoke detectors radioactive? Do they have uranium in them? These are things that you might have heard before, but much of it comes from confusion regarding their base components. For the most part, you have nothing to fear from your smoke detector.

The “Radioactive Boyscout”

Many people vaguely remember the story. In 1994, a boy scout collected a significant amount of radioactive elements in his own backyard. He did so by collecting small amounts of radioactive elements from a number of perfectly ordinary items. There are many household items that can contain radioactivity. And this includes smoke detectors.

More than 80% of the standard smoke detectors in the US contain an amount of americium-241, a radioactive element with a half life of 432 years. It is the americium-241 that allows the contraption to work.

But these are absolutely trace amounts. In fact, even bananas emit radioactivity. Radioactivity in trace amounts is not necessarily negative, it’s only when it’s collected in large amounts that it can become dangerous. Nevertheless, it’s easy to see where the rumor began that smoke detectors could be dangerous or that smoke detectors could contain uranium.

Have Smoke Detectors Ever Contained Uranium?

So why do people think of uranium when they think of a smoke detector? It turns out they aren’t too far off, they’re just several steps removed. Uranium is used to make plutonium, which in turn is used to make americium. But that doesn’t mean that the chemical that results has anything to do with uranium.

It’s easy to think of it this way: imagine burning  wood into ash. Though the ash originally came from the wood, the chemical and physical reactions have made it something that is unrecognizable to wood and shares with it very few properties.

Are Smoke Detectors Dangerous?

All of thee things may sound like something dangerous to have in your home, but they really are not. A smoke detector does not emit most of its radioactive particles, because they’re trapped inside of it. There could be as much as a dose of 9 to 50 nanosievert per year in radiation.


Remember the bananas we mentioned? Well, consuming a banana will give you a dose of about 100 nanosievert. In other words, eating just half of a banana is just as dangerous as having a smoke detector in your home for the course of a year. And it goes without saying that not having a smoke detector is far more dangerous than having one.

It should be noted that though this may give a dose, this radiation is harmless enough that it doesn’t actually penetrate beyond a few layers of skin. There are a number of things that could give you higher doses of radiation than your common smoke detector:

  • Potatoes.
  • Carrots.
  • Lima Beans.
  • Red Meat.

That doesn’t mean those items are dangerous. Small amounts of radiation are harmless and to be expected.

Since the first smoke detector was invented, smoke detectors have always been more useful than harmful. Which types of smoke detectors to use or where to place them might not be as clear, but you don’t need to worry about your smoke detector itself hurting you or your family.

In conclusion, no, smoke detectors are not and have not previously been made with uranium, though you could potentially say that they are made with a chemical that once used to be uranium. For more information about smoke detectors and safety, contact the professionals at Protect America.