Touched a smoke detector and then put hands in mouth?

In summary, the person is concerned about accidentally ingesting americium while handling a smoke detector. They came across a lab manual that advised washing hands after handling radioactive materials, causing further worry. However, the US Nuclear Regulatory Commission states that there is no need to worry as the radiation source in smoke detectors is extremely weak and not readily absorbed by the body. The Australian Radiation Protection and Nuclear Safety Agency also confirms that the source is insoluble and would not be absorbed if ingested. Additionally, the Health Physics Society website explains that the americium is electroplated onto the metal disk and is protected by a thin, chemical-resistant layer, making it nearly impossible to be removed accidentally. The safety warning in the lab manual can be seen as a general
  • #1
vvcurious
Hi.

I have a very embarrassing question to ask.

I was changed the battery in my smoke detector, which is the sort that uses americium to work. I have a bad habit of chewing and swallowing my nails, and also picking and my nose and swallowing the stuff from my nose, too.

I'm paranoid that I inadvertently did one of those two (or both?) after handling the smoke detector.

I recently learned that the americium seems to just be painted on to a metal button inside the plastic casing, which isn't even really well contained in terms of my own smoke detector. I always thought they were super enclosed in a very non-destructable metal casing. SO, basically, now I'm paranoid I ingested some of the americium by these series of actions.

Is that even a rational thing to worry about? Am I missing some details about how smoke detectors work? I understand they are alpha emitters, but since the question is whether or not I ingested it, and not whether or not I got in on my skin I guess it could be.

I came across this lab manual that says you should wash your hands when handling radioactive substances, even after touching a smoke detector, so now I'm like "Ahhh!".

http://myslu.stlawu.edu/~jmil/physics/labs/152_lab/inactive/smoke_detector_old.pdf
 
Biology news on Phys.org
  • #2
Nothing to worry about. It's an extremely weak radiation source in the form that is not readily absorbed by body tissues.

Here's some safety info from the US Nuclear Regulatory Commission:
https://www.nrc.gov/reading-rm/doc-collections/fact-sheets/smoke-detectors.html
The study also looked at doses from misuse. It found that a teacher who removed the source from a smoke detector could receive a dose of 0.009 millirems per year from storing it in the classroom. The teacher would get another 0.001 mrem from handling it for 10 hours each year for classroom demonstrations, and 600 mrem it he or she were to swallow it.
For comparison, 600 mrem is about half of what you'd get from a full-body CT scan.

Here's info from Australian Radiation Protection and Nuclear Safety Agency:
https://www.arpansa.gov.au/understanding-radiation/radiation-sources/more-radiation-sources/smoke-detectors
(...)the hands are very much less sensitive to radiation than internal organs and the time of exposure is likely to be only a few minutes per year, no significant radiation exposure would occur.

The radioactive source in a smoke alarm is extremely insoluble and, if swallowed, would not be absorbed into the body but would pass through the digestive system.

And an answer to a similar question from the Health Physics Society website:
https://hps.org/publicinformation/ate/q11701.html
It is impossible for the 241Am to leach out over time while in your home. Not even small particles of it will flake off. The americium is electroplated onto the metal disk, just like chrome is plated on a car bumper or door handle. It could be removed only by grinding or by using very strong chemical acids. Additionally, the americium is protected by a thin, gold-metal layer that is very chemical resistant. So, the 241Am on the disk of a smoke detector can be removed only if it is done intentionally and by using very aggressive methods.
(I'd treat the safety warning from the linked document as the teacher hammering general good practices into students' heads)
 
  • Like
Likes SciencewithDrJ, rbelli1 and jim mcnamara

1. What should I do if I accidentally touched a smoke detector and then put my hands in my mouth?

If the smoke detector is a traditional ionization type, there is no need to worry. The small amount of radiation emitted is not harmful. However, if you are concerned, you can wash your hands with soap and water.

2. Is it dangerous to touch a smoke detector and then put my hands in my mouth?

No, it is not dangerous. The radiation emitted by traditional ionization smoke detectors is very low and not harmful to humans. However, it is always a good idea to wash your hands with soap and water after touching any type of electronic device.

3. Can touching a smoke detector and then putting my hands in my mouth cause any health issues?

No, it cannot. The small amount of radiation emitted by traditional ionization smoke detectors is not enough to cause any health issues. However, it is important to always wash your hands after touching any type of electronic device to prevent the spread of germs.

4. How long does the radiation from a smoke detector last on my hands?

The radiation from a traditional ionization smoke detector is very low and dissipates quickly. It is unlikely that any radiation would still be present on your hands after a few minutes. However, washing your hands with soap and water is always recommended as a precaution.

5. Should I be concerned if my child touched a smoke detector and then put their hands in their mouth?

No, you should not be concerned. The small amount of radiation emitted by traditional ionization smoke detectors is not harmful, even for children. However, it is always a good idea to wash your child's hands with soap and water after touching any electronic device.

Similar threads

Replies
49
Views
6K
Replies
3
Views
748
  • General Discussion
Replies
3
Views
876
  • General Discussion
Replies
8
Views
10K
  • Other Physics Topics
Replies
5
Views
3K
  • Computing and Technology
Replies
5
Views
2K
Replies
16
Views
2K
Replies
1
Views
2K
  • Computing and Technology
2
Replies
44
Views
14K
  • Chemistry
Replies
5
Views
2K
Back
Top