FOR SAFETY'S SAKECarbon Monoxide: A Killer…Period.

Here is an email someone recently sent to the safety desk (some parts were omitted from the original):

I know this is probably pretty cliché, but I’m writing to you from an anonymous email address because, well, I guess the reason’s pretty obvious.

About a month ago, I had the CO [carbon monoxide] detector in my truck sound an alarm, only I wound up spending about two to three minutes in the truck with the doors shut because I thought the alarm was [audio] feedback. Later that night, I had mild symptoms of carbon monoxide poisoning, which quickly went away when I went to bed.

Recently, I noticed the CO detector in the truck is no longer operational. I’ve reported it a couple of times to my boss, but he doesn’t seem to think it’s a big deal and he’s dragging his feet on getting the detector fixed. He says they’ve never had a problem with CO (even though I reported my own incident the night after it happened) and that he’s never heard of any carbon monoxide poisoning cases in the industry as a whole.

Am I being unreasonable in my concern over this issue? I’m considering refusing to take the truck out until they get the detector fixed or quitting over this. Am I making too big a deal out of something that isn’t that big of an issue? Or do you think there’s reason to be concerned here?
I don’t want to make this into a public ordeal or anything. I just don’t make enough money to put my life in danger over something as preventable as carbon monoxide [poisoning].

Finally, do you know if there actually has [sic] been any incidents of CO [poisoning] in the industry? If so, could you give [me] details?

I really, really appreciate your help with this, and I’m eagerly awaiting your reply.

Signed, ENG-Op

The website of the American Association of State Highway and Transportation Officials’ Strategic Highway Safety Plan,, lists some sources of frightening data about carbon monoxide poisoning:

• "Press Release: NHTSA Advises of Danger from CO Poisoning Associated with Motor Vehicles." National Highway Traffic Safety Administration, Washington, DC, 1996. Reference number: NHTSA 84-96.

Abstract: The National Highway Traffic Safety Administration (NHTSA) today said that more than one-third of deaths from CO poisoning by motor vehicles occur in winter months, often in garages, and offered tips to prevent it.

• "Unintentional Deaths from CO in Motor Vehicle Exhaust." Baron, Roy; Backer, Ronald C.; Sopher, Irvin M. American Journal of Public Health, Volume 79, Number 31, 1989.

Abstract: The study investigated the circumstances of unintended CO deaths from motor vehicle exhaust. Of 64 episodes involving 82 deaths investigated by the West Virginia Office of the Chief Medical Examiner, 1978-84, 50 occurred outdoors in older vehicles with defective exhaust systems and 14 occurred in enclosed or semi-enclosed home garages. Blood alcohol was detected in 50 (68%) of 74 victims tested; 34 had blood alcohol concentrations greater than or equal to 0.10. We suggest increasing public awareness of the hazards of motor vehicle exhaust and enforcing vehicle inspection regulations.

Not only are these statistics sobering, they are educational. Obviously, we have to pay attention to CO poisoning issues in the winter, when engines run for heat and windows are closed for warmth. Is it the same in the summer?

Yes, as vehicles operate with close to the same closed for environmental comfort.

Another website,, also contains some enlightening CO information. Dr. David Penny, who has taught extensively at the undergraduate, graduate, medical, and post-graduate levels, assembled the site. He has more than 30 years of experience with CO toxicology in animals and humans.

The page contains a chart detailing five categories of syndromes of CO poisoning. These are: Somatic/ Physical Symptoms, Cognitive/ Memory Impairments, Affective Disorders (Emotional/Personality Effects), Sensory and Motor Disorders (Visual, Auditory, etc), and Gross Neurological Disorders.

Symptoms within the categories were headache, nausea, vomiting, muscle pain, joint pain, chronic fatigue, dizziness, vertigo, numbness, tingling, paresthesia, executive functioning deficits, attention/concentration problems, multitasking problems, verbal and/or visual deficits, word-finding problems, word-order problems, short-term memory problems, loss of intellectual capacity, slowed cognitive processing, mood changes, irritability, depression, anxiety, tearfulness, apathy, lack of motivation, loss of interest, anger, temper, social relationship problems, sleep disturbance, personality change (eg., psychosis, schizophrenia), blurry vision, double vision, accommodation problems, tinnitus, loss of hearing, hypersensitivity to chemicals, slowed fine motor speed, coordination, decreased gross motor strength, speaking, eating, swallowing disorders, seizures, aphasia, gait disturbances, balance problems, and tremor.

These symptoms may continue for weeks, months, or years after termination of CO exposure/poisoning.

To answer the question in the email asking if there were "actual incidents" in our industry: Yes, the letter itself detailed one. It’s part of the environment. Realization and prevention of CO exposure is a part of the job.

Mark Bell publishes the ENG Safety Newsletter. He can be reached at: