According to the National Fire Protection Association (NFPA), nearly two-thirds of home fire fatalities occurred in properties without working smoke alarms. That statistic is even more tragic when one considers that fires kill more Americans every year than all other natural disasters combined. Even without an extinguisher, a working alarm will cut the likelihood of dying in a fire by 51%.
These detectors are more responsive to fires that spend a long time smoldering before bursting into flame. This optical detection method consists of a light source and a sensor positioned at an angle to one another within the sensing chamber. When smoke enters, the particles scatter the light, and when the deflected light strikes the sensor the alarm is triggered.
These alarms are best for sensing quickly flaming fires. In this method, a radioisotope ionizes the air within the sensing chamber, causing a small current to pass between two electrically charged plates. When smoke enters, the ions attach to the particles, disrupting the current and triggering the alarm.
You don’t necessarily have to choose between one type or the other. There are dual sensor smoke detectors available that use both ionization and photoelectric technology to sense smoldering and flaming fires. But for all intents and purposes, photoelectric is better. The reasons for this include:
- Most home fire fatalities are due to smoke or carbon monoxide inhalation, not fast-burning flames.
- Ionization alarm response times are often slower. One study by Texas A&M University found that in smoldering fires, the likelihood of a fatality is 4% with photoelectric and almost 56% with ionization alarms.
- Ionization detectors are more likely to give a nuisance alarm caused by things such as shower steam or ordinary cooking smoke.
The “working” part of having a working smoke alarm depends on both power and placement, though type matters, too. The U.S. Fire Administration (USFA) states that the presence of non-operable alarms in the home is often due to a high rate of nuisance alarms, prompting people to remove the battery—definitely not something you want to do. If you’re getting nuisance alarms, change the placement or purchase a new alarm with better signal discrimination, such as a photoelectric smoke detector.
A detector can be hardwired into your home’s electrical system, but most are battery-operated. The earliest home alarms were powered by 9-volt batteries, which are still commonly used today. These alarms should be tested monthly, given a new battery yearly, and replaced every 10 years. A detector with a non-replaceable 10-year lithium battery will eliminate the need to replace the battery every year.
The USFA recommends placing an alarm on every level of your home, and both inside and outside of sleeping areas.
Heating and cooking fires are the two leading causes of home fires. A related danger in the home is the emission of carbon monoxide (CO), an invisible, odorless gas created by incomplete combustion in fuel-burning appliances such as furnaces, ranges, or heaters. Exposure to high levels or prolonged low levels of CO can be poisonous or even fatal, particularly for infants, pregnant women, or those with heart or respiratory conditions. According to Underwriters Laboratories standards, a home carbon monoxide detector must trigger an alarm before CO levels reach the following limits:
- 400 parts per million of CO after 4 to 15 minutes
- 150 ppm after 10 to 50 minutes
- 70 ppm after 60 to 240 minutes
The USFA and NFPA recommend installing carbon monoxide detectors throughout the home, either alongside smoke detectors or as part of a dual smoke/carbon monoxide-detecting alarm.
A fire extinguisher is an essential piece of home safety equipment, but just as important is having the right extinguisher type and training. If you’ve never been trained in how to use and maintain an extinguisher, contact your local fire department for information on how and where you or your family could receive training.
- Class A: these are for putting out ordinary combustible materials such as wood, paper, cloth, or plastics
- Class B: these are intended for flammable liquids such as gasoline, grease, cooking oil, or oil-based paint
- Class C: these are for electrical fires involving energized or plugged-in appliances or equipment
As you shop for fire extinguishers, you’ll see that each one is named with a series of letters and numbers. This is the Underwriters Laboratories label. The letter refers to the class of fire, but the preceding number can be a little more confusing.
For an A extinguisher, the number refers to how much fire retardant it contains. Each 1 is equivalent to 1.25 gallons of water, e.g. a UL-rated 4-A extinguisher holds the equivalent of five gallons of water.
For a B or C class extinguisher, the number refers to the size of the fire it can handle. With a 40BC extinguisher, for example, multiply the number by 2.5 to get the number of square feet of fire it can handle—in this case, 100 square feet.
Fire professionals recommend a portable ABC multipurpose fire extinguisher as the best option for overall home safety. If it’s for the kitchen or garage, a BC extinguisher is suitable. When choosing a size, make sure it’s one that everyone in the home can easily handle. Something between a 1A10BC extinguisher and 3A40BC should be manageable. Keep a small fire extinguisher on each level of your home, supplemented by a large extinguisher in a central location.