The microorganism is additionally prone to high salt, high oxygen, and also reduced pH levels. The toxic substance itself is swiftly destroyed by heat, such as in extensive cooking. The spores that produce the toxic substance are heat-tolerant and also will survive boiling water for a prolonged period of time. Over the following 3 decades, 1895-- 1925, as food canning was coming close to a billion-dollar-a-year sector, botulism was becoming a public health threat. The seven contaminant serotypes (A-- G) are generally divided by their antigenicity.