In every truck we have owned since 2005 we have had a Carbon Monoxide/Smoke alarm somewhere in the sleeper. Some people believe that Carbon Monoxide (CO) is not something to worry about in a truck, or not worth the expense of having an alarm.
So, just what is CO and how is it produced? I'll tell you, this is what I found at the United States Consumer Product Safety Commission (CPSC)
www.cpsc.gov/en/Safety-Education-Centers/Carbon-Monoxide. "Carbon monoxide (CO) is a deadly, colorless, poisonous gas. It is produced by the incomplete burning of various fuels, including coal, charcoal, oil, kerosene, propane, and natural gas. Products and equipment powered by internal combustion engines such as portable generators, cars, lawn mowers, and power washers also produce CO." While the diesel engine was not mentioned in the producers of CO, in at least one of the concentration camps in Germany, the Nazi’s used "powerful diesel engines" to produce enough CO to kill their intended victims.
Of what I’ve read a properly tuned diesel will not produce enough CO to kill a human in a reasonable amount of time, 4 hours or less. With that said, a diesel engine can be made, quite easily, to produce more than enough CO to kill within 30 minutes. The killing volume is 4000 parts per million or a 4% ratio to air. That doesn't sound like much but it doesn't take much.
From an article by several doctors at,
www.jabfm.org/content/21/1/55.full, discussing the toxicity of diesel exhaust, "On an equal horsepower basis, diesel exhaust is 100 times more toxic than gasoline exhaust, even when carbon monoxide is considered." This leads me to believe breathing diesel exhaust is NOT good for you. Will it be CO in diesel exhaust that kills you? Probably not. Will diesel exhaust have adverse effects on your health? Yes, but from what I’ve read it's not something you should fret about, unless you work where the exhaust fumes could get concentrated, like within a building.
Now I will say if you have a drafty sleeper and the neighboring truck has a gasoline fueled generator you could get CO poisoning from that exhaust, if conditions are just right. Wouldn't you feel better if you had that CO alarm? I know I would. I found carbon monoxide/smoke detector alarms in one unit on-line starting at around $28 up to over $200. Stand alone CO detectors starting around $11. A cheap piece of insurance if you ask me. Maybe you could ask for one for your birthday or Christmas, if you don't want to buy one for yourself.
Bottom line, it won't kill you to have one in the truck, but it may save your life. For no more than they cost what could it hurt?