[Hypnodisc]

I've just replaced an incredibly old smoke alarm that was no longer working.

The front plate literally fell off, and theres a black 'box' which has the Radioactive symbol on it, and AMERICIUM 33KBQ engraved into it!

I'm a little worried! Have I been exposed to any sort of radiation.. and why is there a radioactive substance in the old smoke alarm?

[Milky Joe]

All smoke alarms are radioactive.

[skp20040]

Originally Posted by Hypnodisc

I've just replaced an incredibly old smoke alarm that was no longer working.

The front plate literally fell off, and theres a black 'box' which has the Radioactive symbol on it, and AMERICIUM 33KBQ engraved into it!

I'm a little worried! Have I been exposed to any sort of radiation.. and why is there a radioactive substance in the old smoke alarm?

Wait until its dark and the see if you start glowing in the dark !! Sorry, in all seriousness , unless you start undoing that actual black box and digging it apart it etc then it will do you no harm. The only time it would possibly harm you without playing about with it is if you burnt it and inhaled the fumes.

All Optical smoke alarms are free of any radioactive substances.

[peripheral]

Originally Posted by skp20040

The only time it would possibly harm you without playing about with it is if you burnt it and inhaled the fumes.

And if your smoke alarm is on fire you've probably got more to worry about than the radioactivity....such as getting out of your burning house.

[Hypnodisc]

Originally Posted by skp20040

Wait until its dark and the see if you start glowing in the dark !! Sorry, in all seriousness , unless you start undoing that actual black box and digging it apart it etc then it will do you know harm. The only time it would possibly harm you without playing about with it is if you burnt it and inhaled the fumes.

All Optical smoke alarms are free of any radioactive substances.

Phew I just got a little worried when I saw a big-arse yellow radioactive symbol! Enough to make my heart skip a beat anyway.

Can I just throw this in the normal dustbin?

[DM Andy]

Originally Posted by Hypnodisc

I'm a little worried! Have I been exposed to any sort of radiation.. and why is there a radioactive substance in the old smoke alarm?

Most smoke alarms use Americium-241 to detect smoke and hot air, thus triggering the alarm. Some gamma radiation is emitted by the smoke alarm but all the alpha radiation is blocked by the black box.

Living for a year within 1 metre of a smoke alarm would give you a radiation dose of 1.5 millisievert per year, which is about 1/1000th of the radiation that we receive normally. If you held a smoke alarm in your hand then you would get a significant dose, but you're not going to do that are you?

The Americum is chosen because of it's very high melting point (it's designed to work in a fire). Even in a house fire, the material will not melt and would not be a health hazard.

[DM Andy]

Originally Posted by Hypnodisc

Phew I just got a little worried when I saw a big-arse yellow radioactive symbol! Enough to make my heart skip a beat anyway.

Can I just throw this in the normal dustbin?

Yes, normal dustbin with your non-recyclable waste.

[tenofspades]

If you held a smoke alarm in your hand then you would get a significant dose, but you're not going to do that are you?

Most people tend to though to put them up...

[HenryGarten]

Originally Posted by Hypnodisc

I've just replaced an incredibly old smoke alarm that was no longer working.

The front plate literally fell off, and theres a black 'box' which has the Radioactive symbol on it, and AMERICIUM 33KBQ engraved into it!

I'm a little worried! Have I been exposed to any sort of radiation.. and why is there a radioactive substance in the old smoke alarm?

One gets radiation from all sorts of things. Sleeping with another human gives you a dose of radiation (among possibly other things ) but it does not to worry people too much.

[malaikah]

Originally Posted by tenofspades

Most people tend to though to put them up...

They don't do so permanently though!

[tanstaafl]

Originally Posted by Hypnodisc

I've just replaced an incredibly old smoke alarm that was no longer working.

The front plate literally fell off, and theres a black 'box' which has the Radioactive symbol on it, and AMERICIUM 33KBQ engraved into it!

I'm a little worried! Have I been exposed to any sort of radiation.. and why is there a radioactive substance in the old smoke alarm?

A kBq is short for kilobecquerel, a becquerel being a measure of radioactivity, namely 1 radioactive disintegration per second. Therefore, in your source, 33,000 Americium nuclei are decaying each second.