BRK First Alert Carbon Monoxide Detectors

CPSC Recommends at LEAST One CO Detector Near Sleeping Areas

Low Price Guarantee


What's special about these carbon monoxide sensor?

  • Electrochemical sensor is the most accurate type of carbon monoxide sensor available
  • The dual function test button doubles as a silence button during unwanted, false, or low battery alerts
  • Alarm will “chirp” when the battery is low in power which means its time to replace the battery
  • Click for More Features

The BRK First Alert Carbon Monoxide Detectors are designed to warn you when there is toxic CO gas present in the air. CO gas is the leading cause of death by poisoning in the U.S. Everyone is at risk. Especially at risk are unborn babies, infants, senior citizens and people with coronary or respiratory problems. More


BRK-CO5120BN BRK First Alert - with Battery Back Up 5.40" dia x 1.86" H 0.4 lb
BRK-CO5120PDBN BRK First Alert - with Digital Display & Battery Back Up 5.40" dia x 1.86" H 0.5 lb
BRK-CO600B BRK First Alert AC Plug-In Portable 4.75" L x 3.3" H x 1.5" D 0.4 lb
BRK-CO615B BRK First Alert AC Plug-In Portable with Battery Back Up 4.75" L x 3.3" H x 2.1" D 0.5 lb
BRK-CO400B BRK First Alert Battery Powered Carbon Monoxide Alarm 4.75" L x 3.3" H x 1.5" D 0.4 lb

CO alarms are becoming part of building code throughout the country. The full line includes 120V AC wired-in, 9V DC/battery operated, and 120 VAC plug-in models. Choose the model that meets the needs of your particular installation!

  • The Alarm Action Chart identifies what to do in the event the unit is in alarm
  • These are perfect for residential and institutional applications including sleeping rooms of hospitals, hotels, motels, dormitories and other multi-family dwellings as defined in standard NFPA 720
  • Models are all equipped with electrochemical CO sensor, an 85dB horn, a single button for test/silence and an LED power indicator
  • UL 2034 Rated
  • 5 year limited warranty


CO5120BN - Carbon Monoxide Detector 120V w/ Battery Back Up
First Alert CO5120BN AC Powered Carbon Monoxide Alarm with Battery Back-Up is a single or multi-station CO alarm installs in short time and can be interconnected with up to 18 other CO detectors and smoke alarms.

CO600B - AC Plug-In Portable Carbon Monoxide Alarm
Model CO600B meets codes where there is a requirement for plug-in AC carbon monoxide detectors. First Alert CO600B features an Alarm Action Chart which identifies what to do if the unit is in alarm. The CO600B is designed to be plugged directly into a standard non-switched outlet.

  • Universal mounting feature allows you to install on a wall, ceiling, or simply place on a tabletop
  • LED indicator light lets you know if the unit is functioning and if there is an alert
  • Never a need to replace carbon monoxide sensor

CO615B - AC Plug-In Portable Carbon Monoxide Alarm w/ Battery Back Up
First Alert CO615B is equipped with a backlit digital display that shows you the exact CO levels and has Peak Level Memory, which means it remembers and displays the highest levels detected when the Peak Level button is pressed. Backlight illuminates only when any button is pressed or unit is in alarm. This unit also features a line cord and remote control test/silence; using most standard household IR remote controls, the alarm functions can be tested or unwanted alarms silenced.

  • Plug directly into an outlet or the line cord utilized to mount the unit to the wall away from the outlet or to place unit on a tabletop
  • For tabletop use the unit should be placed no higher than three feet from the floor
  • Mounting anchors and screws are included for wall mounting
  • AC direct plug in allows you to plug this detector into any standard wall power outlet
  • The battery backup means the detector is functioning even during a power outage
  • Mounting equipment provided with your unit
  • Program any TV Remote to Test & Silence the alarm so you don’t have to pull a ladder out each time
  • No replacement modules needed for co sensor

CO400B - Powered Carbon Monoxide Alarm
The First Alert CO400B is a battery operated, 3V (two 1.5V AA batteries) single station carbon monoxide alarm. This device is perfect for use in recreational vehicles and other areas where you might sleep or be in for extended periods. The front access battery door allows battery access without removing the unit from the wall. This is a battery operated carbon monoxide alarm designed for portability and installs almost anywhere.

  • Batteries are included with your detector which will ensure functioning during power outages
  • Easy to install on the wall, ceiling, or even a tabletop with included hardware
  • The test/ silence button enables you to temporarily silence unwanted alarms
  • Samples air once every second
  • Calibrated at four levels for accuracy
  • Unique self testing system alerts if malfunctions
  • 3 indicator lights green power status, yellow service, red warning


  CO5120BN CO5120PDBN CO600B CO615B CO400B
Operating Voltage
120V AC, 60 Hz w/ 9V battery backup 120V AC, 60 Hz w/ 9V battery backup 120V AC, 60 Hz 120V AC, 60 Hz
(2) 1.5V AA batteries
(2) 1.5V AA batteries
Operating Current
0.09 amps (standby/alarm) 0.09 amps (standby/alarm) n/a n/a n/a
Temp. Range
40°F (4°C) to 100°F (38°C)
Humidity Range
10% to 90% relative humidity (RH)
Audio Alarm
85dB at 10 feet
Test Button
Electronically simulates carbon monoxide condition, causing the unit to alarm
Alarm Reset
Automatic when CO clears. Press test/silence button to reset manually Automatic when CO clears.
Press test/silence button to reset manually
18 total with CO Alarms: CO5120PDBN, CO5120BN. Smoke Alarms: SC6120B, 4120, 4120B, 4120SB, 4120AB, 4120SAB, 2002RAC, 100S, 5919, and 5919TH. Heat Alarms: HD6135F, HD6135FB n/a
Metal Oxide n/a n/a n/a Electrochemical
Indicator LED AC power
Constant Red LED n/a
DC Power
Intermittent Red LED Red LED flashes once per minute
Local Alarm
Red LED flashes rapidly, audio alarm Audio alarm (4 beeps, pause, 4 beeps) and rapidly flashing red LED
Remote Alarm
Red LED out, audio alarm n/a n/a n/a
Latching Alarm
Red LED flashes every 5 seconds after local alarm stops, audio off n/a n/a n/a
UL 2034
Alarm Dimensions
5.40" dia x 1.86" H 5.40" dia x 1.86" H 3.3" H x 4.75" L x 1.5" D 3.3" H x 4.75" L x 2.1" D 3.3" H x 4.75" L x 1.5" D
6.4 oz 7.3 oz 3.8 oz 8.7 oz 5.5 oz
(click on images to enlarge)
CO5120 Carbon Monoxide Detector drawing CO600 Carbon Monoxide Alarm Drawing CO400B Carbon Monoxide Drawing






Fire Protection 3M? Fire Barrier Pillow3M™ Fire Barrier Pillow
During a fire, 3M™ Fire Barrier Pillow intumesces (expands) and locks itself into place, completely surrounding the penetrant(s) stopping smoke, fire and toxic gases from spreading to the next room or next floor for the rated time period. They are easy to install and great for retrofit projects. Just remove and replace pillows as needed.

Abesco FP Fire Rated Expanding FoamAbesco FP Fire Rated Expanding Foam
Abesco FP200 Fire Rated Expanding Foam is a fire rated polyurethane expanding foam designed to prevent the spread of fire and smoke from one compartment to another through gaps and voids of fire rated walls or floors.
Kidde CO/Smoke Combo AlarmBattery Operated Carbon Monoxide/Smoke Alarms Combo - Kidde
The Kidde Battery Operated Carbon Monoxide/ Smoke Combo Alarm comes complete with two essential safety features in a single unit. The alarm includes a voice warning system that audibly states “Fire, Carbon Monoxide, Low Battery or Smart Hush Activation”.
carbon monoxide alarmKidde Carbon Monoxide Alarm 120V
Kidde Carbon Monoxide Detectors are a vital part of your home's safety system. This essential device helps warn of carbon monoxide levels is inter-connectable with other Kidde devices, such as smoke alarms and heat detectors on one wiring network.
child safety Child Safety Kit
Whether you're a new parent or just looking for a unique baby shower gift, our Child Safety Kit contains a mix of both tried-and-true and not-so-common childproofing products that will work together to make any home a safer place for babies and small children. In addition to the familiar cabinet/drawer locks and furniture corner covers, we've mixed in a few of our own electrical safety and cable management specialties to take childproofing to the next level.

Do you have any question about this product?
Let our experts and customers resolve all your doubts

Did you know that we can give you a quote for most of our products, including shipping?

You can also call us toll free 866.222.0030

What can make this page better?

We do everything we can think of to provide you with the product specs, images and ordering info you need, but if we're missing something or still have room to improve, please let us know. Your comments, suggestions and questions are the best tools we have for serving you better!