Do you know what type of smoke alarms are in your home? Most of us have no idea. Find out why replaced our smoke alarms!
Why type of Smoke Alarm Do You Have?
A majority of US homes (90%) have ionization smoke alarms. (Ionizing are the least expensive.) Roughly 5% have photoelectric, and the rest have none. Most of us have no idea what the difference is between the two types.
Two types of smoke detectors
1. Ionizing
Ionizing smoke alarms contain a radioactive substance called americium-241. The americium-241 is located between two electrically charged plates and ionizes the air which causes current to flow between the plates. When smoke enters the chamber, it disrupts the flow of ions which reduces the flow of current and activates the alarm. This type is more responsive to flaming fires.
2. Photoelectric
Photoelectric smoke detectors aim a light source into a sensing chamber at an angle away from the sensor. Smoke enters the chamber, reflecting light onto the light sensor which triggers the alarm. This type of alarm is more responsive to fires that begin with a long period of smoldering. There are hardwired, battery operated photoelectric alarms or strictly battery operated.
Safety of ionizing smoke alarms
Ionizing smoke alarms are assumed to be safe, as the radioactive substance is shielded. Americium-241, however, is not naturally occurring and is considered by some to pose a health risk. According to the World Fire Safety Foundation:
“Americium-241 is a malleable, silvery white metal that does not occur naturally. It was first produced in 1944 in a nuclear reactor at the University of Chicago. Nowadays it is mainly produced as a byproduct within nuclear reactors and it is extracted from spent nuclear fuel rods.
Its radioactive half-life is 430 years but in total it takes millions of years for it to finish its radioactive decay process.”
For me, the most compelling argument against ionizing smoke detectors is found in the book Light, Radiation, and You. Author John Ott (1909-2000) is best known for his work in the field of time-lapse photography. However, he also was a pioneer in the field of full spectrum lighting. In his third book published in 1980, Ott decries the muscle-weakening impact of fluorescent lights, digital watches, synthetic clothing, and ionizing smoke detectors. Ott categorizes items into either neutral frequencies that do not cause muscle weakening or stress frequencies that do. According to Ott,
“Synthetic materials have varying degrees of stress effects in causing muscle weakness. Vinyl and polyester seem to cause the greatest loss of strength and acrylic the least. Different electronic devices also cause varying degrees of muscle strength loss, as do processed foods. In testing any specific item, make certain you are not involving any offsetting or counteracting frequencies such as digital watch or ionizing-type smoke detector. The digital watch has only a short range effect while the ionizing smoke detector will weaken muscles within a range up to 65 feet. The counteracting effects of certain processed foods are also affected by the time factor, which usually lasts about four hours after food is consumed.
My recommendation would be to use as many neutral stress foods, materials and electrical devices as possible, and avoid or eliminate the stress frequency items as quickly as practical.”
(Interestingly, Ott attributed the increased number of C-sections in hospitals to weakened uterine muscle strength from electric monitoring devices and fluorescent lighting.)
The decision to change smoke detectors
Since our mold journey began in 2007, I have been on a quest to strengthen our immune systems through environment, water and food. I have had an interest in electromagnetic science, but haven’t had the energy to take hold of it. Thanks to my continuing study in the field of Building Biology and a recent Environmental Radiation Inspection, I felt ready to embrace Dr. Ott’s advice.
How to make the change
To determine what kind of smoke detector(s) in your home look at the fine print on the back. You’re looking for Americium-241 or AM-241. You may see something like this:
Here are your replacement options:
Combined ionizing and photoelectric
For fire safety reasons this is the top recommendation since it offers the best of both worlds in terms of smoldering and flame fires. If you’re trying to avoid ionizing smoke alarms, then this combination is not the one to choose.
Battery-operated photoelectric
These are the easiest to install, but diligence is necessary to stay up with battery replacements.
Battery-operated, hardwired photoelectric
The wiring allows the smoke detectors to be linked, so that when one goes off they all go off. The battery offers added insurance in the event the power goes out. If your ionizing alarms are hardwired then you will want to replace with hardwired photoelectric.
Consumer Reports, in its most recent tests, rated the dual-sensor Kidde PI9000 as the top-performing alarm. We purchased BRK Hardwire Smoke Alarm with Photoelectric Sensor and Battery Backup.
How to replace
You’ll have no trouble with battery operated. If hardwiring is involved it’s a bit more complex and may require an electrician. My husband is the first one to say he isn’t the handiest, but he was able to change all of ours. He simply checked that the wiring was the same for the new detector and connected the wiring to the panel. He also changed out the plastic rim attached to the ceiling since they were different in size. (This created a bit of an eyesore if one looks closely but I don’t care!)
What about disposal?
There are no clear guidelines from the EPA, except to say that “waste reduction and minimization” is encouraged. I took ours to the local fire station in a box.
Curie Environmental Services is the first company in the United States to offer smoke alarm recycling. (Find them here.)
It’s easy to feel overwhelmed when it comes to decisions like this. In fact, the choices seem endless. I do the best with what I know and give myself time to process new information. For now, I’m glad we made the transition from ionizing to photoelectric smoke alarms.
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Very informative article. Very well written!
Thanks so much, Andrea!
Thank you, Angela. 🙂
Have you read anything about carbon monoxide alarms? In our city both smoke and CO alarms are required. I wonder if everything you have written above applies to the combo as well. Thanks.
This is a great question, Mar. It appears they make photoelectric with CO alarms and I would assume that is better than the ionizing and CO combination. I’m looking at this one:
http://www.amazon.com/First-Alert-PC910-Photoelectric-Detector/dp/B00J5U8S6E/ref=sr_1_1?ie=UTF8&qid=1423328332&sr=8-1&keywords=carbon+monoxide+detector+with+smoke+alarm
I haven’t read anything negative about the CO alarm itself. Let me know if you come across something.
I did NOT know this! Thank you!
I had no idea! Wow. Thanks for the article!
Whoda thunk?! The things you learn.. wow! Thanks for sharing. =)
Crazy how we have to watch out for everything these days… wish companies would stop using toxic stuff!
Thank you Andrea for this post as I never realised this before. When we get home we will check what kind of smoke alarm we have and get the best one.
Oh, my goodness– all of the things we never think about! I don’t know what kind of smoke alarm we have right now, but we are moving, and I will definitely keep this in mind for our new home!
Wow! I have never even considered the fact that smoke detectors could contain radiation! Now I’m curious to know which one is installed in my apartment…
Thanks for the well informed article! 🙂
Thanks for this super thorough post. I had no idea. Pinning.
Gosh so many things I never even think of! Thanks, this is good to know!
Great information! And probably not well-known to most. Thank you so much for sharing, Andrea!
I had no idea about this! Thanks for sharing this info.
Ionizing smoke detectors are absolutely not harmful, unless you plan on eating them. Am-241 undergoes alpha decay — big, heavy, slow particles. Even if the plastic case of the smoke alarm didn’t block it completely, a couple inches of air would. The notion that ionizing smoke alarms cause muscle weakness at any distance is, to be frank, ridiculous.
Yeah Am emits some gamma, but the amount in a smoke detector is minimal, thus minimal total activity, and the gamma rays have a low energy level. Add to this the inverse square law — radiation exposure decreases inversely proportional to the square of the distance: that is, if you double the distance, the exposure is reduced by a factor of four. At the face of the detector, say an inch from the source, the exposure is minimal, at two inches it’s a fourth of that, at four inches (three inches from the face), it’s a fourth of that — one sixteenth of the original dose. At 32″ away, your exposure is 0.098% that of direct contact (100/4^5 or 100/32^2). At 65 feet (780 inches), you’re at 0.00016%. At any of these distances, this exposure is completely overwhelmed by natural background.
Your safest bet is to have combination units, as the benefits far outweigh the perceived risk.
I appreciate your perspective Andy and I know this is the prevailing thought. I feel much better about the photoelectric in my home – but these are individual decisions. I at least wanted to give others the opportunity to think it through.
Well you learn something new everyday… 🙂 Thank for sharing, very informative!
Very interesting! I’ve never really thought about any of this. Of course, we live in an apartment, so we only have so much control over what is in here.
Wow! I had no idea. What a good reference.
I have just replaced my hardwired photoelectric alarms only to discover that the plastic covers’ outgassing is causing me to have to visit the doctor as I started to itch, have a metallic a taste and a burning face feeling.
As it is a photoelectric alarm which is good but the plastic outgassing is not, what would you recommend to replace them or is there a safe plastic covering?
Kind regards
Oh that is too bad, Darlene! Could you let the new alarms off gas outdoors for a bit? That may be enough to make them tolerable. I’m not aware of a better option, but I would love to look into this. I’ll let you know if I find something.
Thank You. Well written.
Thank you, Susan. I appreciate that.