CDC warns of forklifts as source of CO poisoning

Carbon monoxide (CO) poisoning usually is associated with cars or faulty furnaces, but warehouse workers may be at risk as well. Forklifts used in manufacturing plants may spew out the deadly, odorless gas, possibly poisoning workers in poorly ventilated warehouses or adjoining offices, according to a recent warning from the federal Centers for Disease Control and Prevention (CDC) in Atlanta.

For occupational health providers, there is a particular challenge because the symptoms of CO poisoning — headaches, nausea, and dizziness — often masquerade as other illnesses and it may be misdiagnosed. CO is a colorless, odorless gas released as a byproduct of incomplete fuel combustion.

In one case in 1998, 75 workers at a plastic manufacturing plant suffered from headaches, dizziness, and weakness. (MMWR 1999; 48:1,121-1,124.) Of the 10 who went to emergency rooms for treatment, many were misdiagnosed — some with migraines, others considered to have had a fainting episode.

The cause of the outbreak was determined to be high levels of CO emitted by forklifts, compounded by a malfunction in an exhaust fan.

Proper diagnosis is important for providing treatment. People exposed to CO can be treated in a hyperbaric chamber if their illness is recognized, according to the CDC report. "CO poisoning associated with indoor combustion sources has long been recognized but continues to be a problem in the United States.

The events described in this report illustrate factors that result in failure to adequately prevent CO poisoning and to promptly recognize such incidents when they occur."