A spore-forming bacterium that produces a potent nerve toxin causing botulism, a rare but life-threatening illness linked to improperly processed low-acid…
Improperly home-canned or under-processed low-acid foods such as vegetables, meat and fish, along with vacuum-packed, sous-vide and fermented products and garlic or herb infused oils, are the classic risks. These low-oxygen environments let the toxin form.
Symptoms usually start 12 to 36 hours after eating and affect the nerves, causing blurred or double vision, drooping eyelids, trouble swallowing and speaking, and muscle weakness that can lead to paralysis. It is a medical emergency.
Thorough heating destroys the toxin, but the heat-resistant spores can survive normal cooking. Foods eaten cold from a pack are riskier than foods boiled or cooked hot immediately before eating.
Home canning of low-acid foods such as vegetables, meat and fish is discouraged in Australia because home kitchens cannot reliably reach the temperatures needed to destroy the spores. High-acid foods and validated commercial processing are safer.
Garlic can carry botulinum spores, and oil provides a low-oxygen environment. Left at room temperature the spores can grow and produce toxin, so garlic and herb infused oils should be kept refrigerated and used quickly.