The 85dB Carbon Monoxide Alarm is a tasteless, odorless and invisible gas, but the effects of carbon monoxide poisoning can be deadly, which is why it’s often referred to as the “silent killer.” Carbon monoxide can be emitted from many household appliances including refrigerators, water heaters and space heaters. This is why carbon monoxide detectors are so important in a home. The detectors are designed to measure CO levels and sound an alarm if dangerous levels are found. It’s important to note that carbon monoxide alarms and smoke alarms differ.