What Is Bacillus Cereus?
The FDA's Bad Bug Book describes two types of B. cereus illness. In the first, the bacteria make a toxic substance in the small intestine after contaminated food is eaten, causing diarrhea, cramps and sometimes nausea, usually without vomiting, with symptoms starting in about 6 to 15 hours and usually clearing within a day or so. The second type occurs when B. cereus makes a different kind of toxin in the contaminated food itself, and it most often affects rice and other starchy foods.
It says vomiting-type outbreaks have generally been associated with rice products, though other starchy foods such as potato, pasta and cheese products have also been implicated, and that the more bacteria there are, the more toxin and the greater the chance of getting sick. Cooking may kill the bacteria, it says, but might not disable the toxin that causes the vomiting type of illness.
The FDA Food Code says B. cereus can produce its vomiting toxin in food, with the optimum temperature for toxin production between 77°F and 86°F, and the Bad Bug Book says one of the most important protections is keeping food refrigerated at 40°F or lower. The Bad Bug Book cites a CDC estimate of 63,400 episodes of domestically acquired B. cereus illness in the United States each year.
Sources checked September 15, 2026. Every point below links the page it came from.
The sources behind this answer
- Government sourceThe FDA's Bad Bug Book says one type of B. cereus illness causes diarrhea and cramps, usually without vomiting, starting in about 6 to 15 hours and clearing within a day or so. US FDA, Bad Bug Book ↗
- Government sourceThe FDA's Bad Bug Book says the second type of B. cereus illness comes from a toxin made in the food and most often affects rice and other starchy foods. US FDA, Bad Bug Book ↗
- Government sourceThe FDA's Bad Bug Book says cooking may kill B. cereus but might not disable the toxin that causes the vomiting type of illness. US FDA, Bad Bug Book ↗
- Government sourceThe FDA's Bad Bug Book says vomiting-type B. cereus outbreaks have generally been linked to rice products, with potato, pasta and cheese products also implicated. US FDA, Bad Bug Book ↗
- Government sourceThe FDA's Bad Bug Book says one of the most important protections against B. cereus is keeping food refrigerated at 40°F or lower. US FDA, Bad Bug Book ↗
- Regulatory filingThe FDA Food Code says B. cereus can produce its vomiting toxin in food, with toxin production fastest between 77°F and 86°F. US FDA, Food Code 2022 ↗
- Government sourceThe FDA's Bad Bug Book cites a CDC estimate of 63,400 episodes of domestically acquired B. cereus illness in the United States each year. US FDA, Bad Bug Book ↗
Sources checked September 15, 2026. A brand statement is the company’s own claim, which we report but have not verified. Our grades are model-based estimates, not lab tests.