"C. botulinum" is an obligate anaerobe that is widely distributed in nature and is assumed to be present on all food surfaces. Its optimum growth temperature is within the mesophilic range. In spore form, it is the most heat resistant pathogen that can survive in low acid foods and grow to produce toxin. The toxin attacks the nervous system and will kill an adult at a dose of around 75 ng. This toxin is detoxified by holding food at 100 °C for 10 minutes.