Quantcast
4S Ranch Allied Gardens Alpine Baja Balboa Park Bankers Hill Barrio Logan Bay Ho Bay Park Black Mountain Ranch Blossom Valley Bonita Bonsall Borrego Springs Boulevard Campo Cardiff-by-the-Sea Carlsbad Carmel Mountain Carmel Valley Chollas View Chula Vista City College City Heights Clairemont College Area Coronado CSU San Marcos Cuyamaca College Del Cerro Del Mar Descanso Downtown San Diego Eastlake East Village El Cajon Emerald Hills Encanto Encinitas Escondido Fallbrook Fletcher Hills Golden Hill Grant Hill Grantville Grossmont College Guatay Harbor Island Hillcrest Imperial Beach Imperial Valley Jacumba Jamacha-Lomita Jamul Julian Kearny Mesa Kensington La Jolla Lakeside La Mesa Lemon Grove Leucadia Liberty Station Lincoln Acres Lincoln Park Linda Vista Little Italy Logan Heights Mesa College Midway District MiraCosta College Miramar Miramar College Mira Mesa Mission Beach Mission Hills Mission Valley Mountain View Mount Hope Mount Laguna National City Nestor Normal Heights North Park Oak Park Ocean Beach Oceanside Old Town Otay Mesa Pacific Beach Pala Palomar College Palomar Mountain Paradise Hills Pauma Valley Pine Valley Point Loma Point Loma Nazarene Potrero Poway Rainbow Ramona Rancho Bernardo Rancho Penasquitos Rancho San Diego Rancho Santa Fe Rolando San Carlos San Marcos San Onofre Santa Ysabel Santee San Ysidro Scripps Ranch SDSU Serra Mesa Shelltown Shelter Island Sherman Heights Skyline Solana Beach Sorrento Valley Southcrest South Park Southwestern College Spring Valley Stockton Talmadge Temecula Tierrasanta Tijuana UCSD University City University Heights USD Valencia Park Valley Center Vista Warner Springs

The americium-241 in your smoke detector

Photoelectrics are better at sensing a smoldering fire; ionizing detectors are much better at a blaze

By now we’d all glow in the dark like big fireflies. - Image by Rick Geary
By now we’d all glow in the dark like big fireflies.

Dear Matthew Alice: Is it true that the smoke detector, installed by the builders of my condo in '79, has a radioactive element in it? If so, is it strong enough to be harmful in the corner of my bedroom? Yes, I know — why am I asking now, after 15 years! — Bill Cromwell, Mission Valley

If there were any radiation danger from ionization-type smoke detectors. Bill, by now we’d all glow in the dark like big fireflies. And photoelectric-style devices contain no radioactive elements. So no matter which type you have, your health has suffered more from 15 years of worry than from any leaky rays. An ionizing detector has a pill-sized, shielded bit of americium-241, which “ionizes” the air inside the device, completing an electrical circuit. Smoke particles disrupt the connection and trigger the alarm. (In photoelectrics, the smoke scatters a light beam.) And here it comes, the obligatory goofy-but-eye-opening comparison apparently required in every radiation story. If you snuggled under the covers with your ionizing alarm every night for a year, you’d be exposed to a tenth of the radiation dose (0.5 milligram) you’d receive on a round-trip plane flight from New York to L.A., according to the Nuclear Regulatory Commission. All consumer products contribute only 3 percent to the average person’s annual radiation exposure.

Consumers Union poked and pummeled ionizing detectors and imagined every possible ugly scenario while preparing their smoke-detector safety story for the January 1977 issue of Consumer Reports. As you might expect, they say your risk from fire is real; your risk from smoke detectors is virtually nonexistent, assuming you don’t eat one or stick the pellet up your nose. (A few years ago, a creative Canadian decided to commit suicide by cooking the radiation pellets from two smoke alarms in a kettle of onion soup. He ate a bowl or two each week for a month. If it eventually kills him, it could take years. Hope he doesn’t change his mind in the meantime.)

A few more detector tips. The photoelectrics are better at sensing a smoldering fire (the cigarette-in-the-sofa-cushions type); ionizing detectors are much better at sensing a blaze that emits little or no smoke. CU recommends you put both types in some rooms. And don’t throw a conked-out ionizing detector in the trash. It’s against the law. Mail it back to the manufacturer.

Here's something you might be interested in.
Submit a free classified
or view all

Previous article

Oktoberfest beers to drink at home

Pick up a stein, or have this year’s märzen delivered
Next Article

La Jolla Tide Pools meets Craftsman-style renovation

In its early days, the Kline House operated as La Jolla Sanatorium
By now we’d all glow in the dark like big fireflies. - Image by Rick Geary
By now we’d all glow in the dark like big fireflies.

Dear Matthew Alice: Is it true that the smoke detector, installed by the builders of my condo in '79, has a radioactive element in it? If so, is it strong enough to be harmful in the corner of my bedroom? Yes, I know — why am I asking now, after 15 years! — Bill Cromwell, Mission Valley

If there were any radiation danger from ionization-type smoke detectors. Bill, by now we’d all glow in the dark like big fireflies. And photoelectric-style devices contain no radioactive elements. So no matter which type you have, your health has suffered more from 15 years of worry than from any leaky rays. An ionizing detector has a pill-sized, shielded bit of americium-241, which “ionizes” the air inside the device, completing an electrical circuit. Smoke particles disrupt the connection and trigger the alarm. (In photoelectrics, the smoke scatters a light beam.) And here it comes, the obligatory goofy-but-eye-opening comparison apparently required in every radiation story. If you snuggled under the covers with your ionizing alarm every night for a year, you’d be exposed to a tenth of the radiation dose (0.5 milligram) you’d receive on a round-trip plane flight from New York to L.A., according to the Nuclear Regulatory Commission. All consumer products contribute only 3 percent to the average person’s annual radiation exposure.

Consumers Union poked and pummeled ionizing detectors and imagined every possible ugly scenario while preparing their smoke-detector safety story for the January 1977 issue of Consumer Reports. As you might expect, they say your risk from fire is real; your risk from smoke detectors is virtually nonexistent, assuming you don’t eat one or stick the pellet up your nose. (A few years ago, a creative Canadian decided to commit suicide by cooking the radiation pellets from two smoke alarms in a kettle of onion soup. He ate a bowl or two each week for a month. If it eventually kills him, it could take years. Hope he doesn’t change his mind in the meantime.)

A few more detector tips. The photoelectrics are better at sensing a smoldering fire (the cigarette-in-the-sofa-cushions type); ionizing detectors are much better at sensing a blaze that emits little or no smoke. CU recommends you put both types in some rooms. And don’t throw a conked-out ionizing detector in the trash. It’s against the law. Mail it back to the manufacturer.

Sponsored
Here's something you might be interested in.
Submit a free classified
or view all
Previous article

Jackslacks releases Billy Bacon tribute EP When Pigs Fly

Bacon passed away in August 2019
Next Article

La Jolla Tide Pools meets Craftsman-style renovation

In its early days, the Kline House operated as La Jolla Sanatorium
Comments
0

Be the first to leave a comment.

Sign in to comment

Sign in

Art Reviews — W.S. Di Piero's eye on exhibits Ask a Hipster — Advice you didn't know you needed Best Buys — San Diego shopping Big Screen — Movie commentary Blurt — Music's inside track Booze News — San Diego spirits City Lights — News and politics Classical Music — Immortal beauty Classifieds — Free and easy Cover Stories — Front-page features Excerpts — Literary and spiritual excerpts Famous Former Neighbors — Next-door celebs Feast! — Food & drink reviews Feature Stories — Local news & stories From the Archives — Spotlight on the past Golden Dreams — Talk of the town Here's the Deal — Chad Deal's watering holes Just Announced — The scoop on shows Letters — Our inbox [email protected] — Local movie buffs share favorites Movie Reviews — Our critics' picks and pans Musician Interviews — Up close with local artists Neighborhood News from Stringers — Hyperlocal news News Ticker — News & politics Obermeyer — San Diego politics illustrated Of Note — Concert picks Out & About — What's Happening Overheard in San Diego — Eavesdropping illustrated Poetry — The old and the new Pour Over — Grab a cup Reader Travel — Travel section built by travelers Reading — The hunt for intellectuals Roam-O-Rama — SoCal's best hiking/biking trails San Diego Beer — Inside San Diego suds SD on the QT — Almost factual news Set 'em Up Joe — Bartenders' drink recipes Sheep and Goats — Places of worship Special Issues — The best of Sports — Athletics without gush Street Style — San Diego streets have style Suit Up — Fashion tips for dudes Theater Reviews — Local productions Theater antireviews — Narrow your search Tin Fork — Silver spoon alternative Under the Radar — Matt Potter's undercover work Unforgettable — Long-ago San Diego Unreal Estate — San Diego's priciest pads Waterfront — All things ocean Your Week — Daily event picks
4S Ranch Allied Gardens Alpine Baja Balboa Park Bankers Hill Barrio Logan Bay Ho Bay Park Black Mountain Ranch Blossom Valley Bonita Bonsall Borrego Springs Boulevard Campo Cardiff-by-the-Sea Carlsbad Carmel Mountain Carmel Valley Chollas View Chula Vista City College City Heights Clairemont College Area Coronado CSU San Marcos Cuyamaca College Del Cerro Del Mar Descanso Downtown San Diego Eastlake East Village El Cajon Emerald Hills Encanto Encinitas Escondido Fallbrook Fletcher Hills Golden Hill Grant Hill Grantville Grossmont College Guatay Harbor Island Hillcrest Imperial Beach Imperial Valley Jacumba Jamacha-Lomita Jamul Julian Kearny Mesa Kensington La Jolla Lakeside La Mesa Lemon Grove Leucadia Liberty Station Lincoln Acres Lincoln Park Linda Vista Little Italy Logan Heights Mesa College Midway District MiraCosta College Miramar Miramar College Mira Mesa Mission Beach Mission Hills Mission Valley Mountain View Mount Hope Mount Laguna National City Nestor Normal Heights North Park Oak Park Ocean Beach Oceanside Old Town Otay Mesa Pacific Beach Pala Palomar College Palomar Mountain Paradise Hills Pauma Valley Pine Valley Point Loma Point Loma Nazarene Potrero Poway Rainbow Ramona Rancho Bernardo Rancho Penasquitos Rancho San Diego Rancho Santa Fe Rolando San Carlos San Marcos San Onofre Santa Ysabel Santee San Ysidro Scripps Ranch SDSU Serra Mesa Shelltown Shelter Island Sherman Heights Skyline Solana Beach Sorrento Valley Southcrest South Park Southwestern College Spring Valley Stockton Talmadge Temecula Tierrasanta Tijuana UCSD University City University Heights USD Valencia Park Valley Center Vista Warner Springs
Close