Why does this model contain the radioactive part? I am sure you are going to tell me that it is a trace amount and that it has all approvals...

The "radioactive part" is how it works. Don't like it? Don't buy it. Simple. As for false alarms, this unit with its "radioactive part" is actually much more likely to give false alarms that condition people to ignore them. It is also much less sensitive to the smoldering, smoke-producing fires that are more common in homes. That's why ionization detectors are no longer recommended in residential settings. Experts now recommend only photoelectric devices in homes, so if you have these, you should replace all of them with the SC7010B.

Because its a combo alarm where is the best place to install it since smoke rises and carbon monoxide doesn't?

According to the National Fire Protection Association: Choose smoke alarms that have the label of a recognized testing laboratory.Install smoke alarms inside each bedroom, outside each sleeping area and on every level of the home, including the basement.On levels without bedrooms, install alarms in the living room (or den or family room) or near the stairway to the upper level, or in both locations.Smoke alarms installed in the basement should be installed on the ceiling at the bottom of the stairs leading to the next level.Smoke alarms should be installed at least 10 feet (3 meters) from a cooking appliance to minimize false alarms when cooking.Mount smoke alarms high on walls or ceilings (remember, smoke rises). Wall-mounted alarms should be installed not more than 12 inches away from the ceiling (to the top of the alarm). If you have ceilings that are pitched, install the alarm within 3 feet of the peak but not within the apex of the peak (four inches down from the peak).

If the alarm goes off, how can you tell whether it's due to CO or fire if there is no voice alert?

I'm sure we'll all remember the number of beeps for each type of emergency, in an actual emergency, when we've been woken up in the middle of the night. I'll pay the extra $10 per detector and get the voice alert. I humbly suggest you do the same.

What is the manufacture date on these items?

Your warranty starts at the date of purchase. Keep your receipt. Your 5 year shelf life starts the day you power it up. The expiration date is hard coded into the software and only starts the day you plug it in..... This is from BRK WEBSITE

Brand	FIRST ALERT
Style	Hardwired
Power Source	Battery Powered,Hardwired
Color	White
Product Dimensions	1.9"D x 5.6"W x 5.6"H
Item Weight	11.2 ounces
Alarm	Audible
Sensor Type	electrochemical,ionization
Manufacturer	First Alert
Part Number	SC9120BFF-3
Country of Origin	Mexico
Item model number	SC9120B-3
Batteries	2 AA batteries required. (included)
Is Discontinued By Manufacturer	No
Size	3-Pack
Pattern	Detector
Item Package Quantity	1
Included Components	First Alert BRK SC-9120B Hardwired Combination Smoke and Carbon Monoxide Alarms with Battery Backup (3), Mounting brackets (3), 9-volt battery (3)
Batteries Included?	Yes
Batteries Required?	Yes
Battery Cell Type	Alkaline

BRK SC9120B-3 Hardwired Smoke and Carbon Monoxide (CO) Detector with Battery Backup, White, Pack of 3

Description

Specifications

Common Questions