Colourless, Odourless and Dangerous: Know the Signs of Carbon Monoxide Poisoning

An animation of a layer of smoke with a giant hand raised above it and a man sitting in the palm.

Feeling off? Make sure it’s not an undetected toxin in your home.

This past January, 35 children and eight adults at a Montreal elementary school were taken to hospital for carbon monoxide exposure. The source was the heating system.

The elderly, children and people with heart or respiratory conditions may be particularly sensitive to carbon monoxide. Initial symptoms of poisoning are headaches, nausea, vomiting and weakness. Later symptoms include visual changes, confusion, chest pain and, eventually, seizures, coma and death. Given that the initial symptoms are nonspecific, they can be confused with the flu and not addressed until it’s too late.

Carbon monoxide is a colourless, odourless, tasteless toxic gas created when fuels such as gasoline, natural gas, wood or charcoal burn. Exhaust fumes from cars, trucks, stoves, gas ranges, generators and heating systems have carbon monoxide in them.

Prevent deaths from carbon monoxide by knowing how to recognize poisoning. And get out if you think you’re being exposed.

Clues that it may be carbon monoxide poisoning include that the initial symptoms improve when you’re away from the place of exposure and that symptoms are experienced by multiple people in the same place. In up to 40 per cent of patients with significant carbon monoxide exposure, delayed neurologic symptoms can arise three to 240 days after recovery. Symptoms include personality changes, movement disorders, weakness and thought difficulties. They usually occur within 20 days of carbon monoxide exposure, and can last for a year or more.

A version of this article appeared in the April 2019 issue with the headline, “Clear The Air,” p. 21.