Do portable carbon monoxide detectors work?
Portable carbon monoxide detectors are a useful tool for displaying CO levels instantly. Unlike wall-mounted CO detectors that only alarm when elevated CO levels are detected over time, portable detectors show the exact amount of CO in a room in seconds.
About Carbon Monoxide
Carbon monoxide is an odorless, tasteless, colorless toxic gas. Because it is invisible and odorless, exposure to CO can be deadly without you knowing that it exists. That's why many people die from CO poisoning in their sleep at home.
Sources of Carbon Monoxide
Carbon monoxide is typically formed by the incomplete combustion of fuels. When not enough oxygen is available during combustion, carbon monoxide gas is created.
Sources of carbon monoxide include household items such as gas furnaces, gas stoves, gas clothes dryers, gas generators, auto exhaust, leaking chimneys, gas space heaters, and poorly maintained boilers in industrial buildings.
Health Effects of Carbon Monoxide
Carbon monoxide poisoning occurs when the gas builds up in your bloodstream. When there is too much CO in the air, your body replaces the oxygen in your red blood cells with CO. Acute effects are due to the formation of carboxyhemoglobin in the blood, which inhibits oxygen intake.
The health effects of carbon monoxide depend on the concentration of the gas.
See this chart of effects of different carbon monoxide levels.
Average levels of CO in homes without gas appliances, heaters or furnaces can vary from 1 ppm (parts per million) to 5ppm. Levels near properly adjusted gas-burning appliances are typically 5 to 15ppm, while those near poorly adjusted gas burning appliances can be up to 30ppm or higher.
Exposure Limits
The current permissible exposure limit set by the Occupational Safety and Health Administration, OSHA, for carbon monoxide is 50 parts per million (ppm) parts of air, or 55 milligrams per cubic meter as an 8-hour time weighted average.
The National Institute for Occupational Safety and Health (NIOSH) has also established exposure limits for carbon monoxide. NIOSH’s recommended exposure limit is 35 ppm as an 8-hour time weighed average, and 200 ppm as a ceiling. The carbon monoxide exposure limit as set by NIOSH is based on the risk of cardiovascular effects.
See this chart of exposure limits for CO.
Reducing Exposure to CO
The most important step to take when trying to reduce the risk of carbon monoxide poisoning is to make sure gas appliances, heaters and furnaces are properly maintained and adjusted. Cars parked inside attached garages, in auto shops or parking structures should also be monitored. Fresh air fans or open windows should be used as a temporary measure when high levels of CO are expected for short periods of time.
Portable CO Detectors
There are several tools that measure carbon monoxide. One of the most common are inexpensive wall or ceiling mounted carbon monoxide detectors in the home. These devices constantly monitor the indoor air for CO gas and beep if it is detected. In order to alert occupants when they are sleeping, CO detectors are typically installed in bedrooms. In addition, CO detectors are also installed in the kitchen or basement if natural gas is used for cooking or heating.
The challenge faces by manufacturers of CO detectors is that customers don't like false alarms. As a result, home CO detectors are designed to use time weighted averaging of the CO level for detection. Instead of warning instantly, wall-mounted CO detectors only alarm when CO levels are high over time - the higher the CO level, the less time before the alarm.
While time weighted average is useful if the alarm and the CO source are in the same room, it isn't always helpful to pinpoint the source of the CO. This is why furnace installers and repairmen carry portable CO detectors. These hand held devices test combustion efficiency inside a furnace. They have a more accurate carbon monoxide sensor inside that displays the exact CO level in parts-per-million on the screen.
For example, the GasLab Plus Carbon Monoxide Detector is designed to measure carbon monoxide in a variety of applications like furnace repair. These CO detectors feature an audible alarm, data logging with SD card, rechargeable Li-ion batteries, and a large LCD display for easy readability. it is designed to be set on its stand and propped up in your sightline when working in a garage or other space where a potential source for CO is present.
An alternative to a CO-only detector is the GasLab Plus Multi-Gas Detector. In addition to carbon monoxide, this hand-held device measures oxygen, carbon dioxide, PM 2.5 & PM 10 particle count, relative humidity and temperature. This makes it a valuable tool both for measuring CO as well as measuring overall air quality in the home for people with COPD, emphysema, mesothelioma or other respiratory problems.
For people who work around potential sources of carbon monoxide, a personal safety monitor can be useful. They constantly monitor the CO level and alarm if it becomes dangerous. This makes a personal CO safety monitor useful for construction workers, for auto mechanics, for winter backpackers who use gas heaters, for crewmen on ships or in many other situations.
For example, the GasLab SAN-30 is a personal, wearable carbon monoxide detector that measures CO levels in real time. It protects workers in confined spaces like garages, ice-rinks, engine compartments, or anywhere carbon monoxide buildup can occur.
For accurate, low cost CO detection, many of our customers use the dSense Portable Carbon Monoxide detector. This battery operated monitor is simple, easy to use, and shows the exact CO level on the screen. This device is useful during travel for campers, RVers and is an excellent tool for a home owner.
References:
https://www.epa.gov/indoor-air-quality-iaq/carbon-monoxides-impact-indoor-air-quality