Garlic and botulism

Garlic bulbs can pick up the bacteria that cause botulism from the soil. Storing garlic or any other low-acid vegetable in oxygen-free conditions at room temperature can encourage the growth of the toxins responsible for food-borne botulism, a dangerous illness. Eating raw garlic doesn't pose a hazard, but storing it for later use could, if you mix it with oil and keep it at room temperature.