​Imagine one of your drivers wakes up at a truck stop two states away and has no recollection of getting there. The driver calls dispatch and reports feeling sick but remains unsure of what happened. It’s a scary scenario but one that can result from a virtually undetectable threat to your drivers: carbon monoxide poisoning.

Carbon monoxide (CO) is an odorless, colorless gas that can cause sudden illness and death when a person is overexposed to it. Common symptoms of CO poisoning include headaches, dizziness, weakness, nausea, vomiting, chest pain and confusion.

Drivers can be exposed to carbon monoxide from truck exhaust fumes and system leaks. Per Federal Motor Carrier Safety Administration (FMCSA) regulation 393.83, exhaust systems should discharge to the rear of the cab. No part of the exhaust system should leak or discharge forward of or directly below the driver/sleeper compartment. Drivers should perform regular maintenance checks on their exhaust systems to make sure there are no leaks. If a leak is detected, it should be fixed before the driver’s next trip.

In addition to leaks from their own truck, exhaust fumes from other trucks can be dangerous to drivers. While parked at truck stops, drivers are in close proximity to other trucks that may be idling or using auxiliary power units (APUs). If your drivers have their windows down while parked near idling trucks, there is a chance exhaust fumes will make their way into the cab. Keep in mind, however, exhaust fumes can enter the interior of a vehicle even if windows and vents are closed.

In response to the dangers like carbon monoxide emissions, many states and cities place restrictions on engine idling. The American Transportation Research Institute provides a driver cab card and company compendium to help with idling guidance.

Because carbon monoxide is nearly impossible to detect, drivers may not realize they are being exposed to it until it’s too late. All of your drivers should have a battery-operated CO monitor or detector in their cab that sounds an alarm when CO levels are too high. Look for CO monitors that are designed specifically to handle the motion and stress of a moving vehicle.

If the CO detector goes off while your drivers are on the road, they should immediately pull into a safe, legal parking spot and exit the cab into fresh air. If they are stopped when it goes off, they should exit the truck and quickly move away from it. Once out of the truck, they should call 911 to get medical attention. They should not re-enter the truck until the source of CO exposure has been determined.

Drivers need to err on the side of caution. They should not continue driving if they exhibit any symptoms of CO poisoning, even if their CO monitor doesn’t sound. In some cases, people can black out from CO poisoning so it’s incredibly dangerous for drivers to remain behind the wheel if they have been exposed to CO.

Take action today to arm your drivers with CO monitors and the knowledge they need to recognize the symptoms of CO poisoning before it’s too late.