A report published in the latest issue of the Centers for Disease Control and Prevention’s journal Morbidity and Mortality Weekly Report offers a good reminder for everyone that food poisoning doesn’t just come from undercooked meat.

Researchers from the Public Health Agency of Canada reported that between November 2016 and April 2017, 30 people in Canada became ill after eating raw or uncooked flour contaminated with E. coli. This is the first time a particular strain of E. coli, called non-O157, has caused an outbreak in Canada, according to the report, and the first outbreak linked to flour there in general.

Though the CDC says that no cases of illness related to this outbreak have been reported in the U.S., a similar situation did occur here last year. “Given this outbreak and the one in the U.S. last year linked to flour, it’s important for people to know that raw flour can be contaminated and should be cooked or baked thoroughly before eating,” a CDC spokesperson said.

Non-O157 is an understudied strain of E. coli, mostly because labs only recently starting testing for it, according to the CDC. But it has been responsible for outbreaks in the U.S. in the past. It can cause abdominal cramps and bloody diarrhea but is typically less severe than E. coli O157 (which has been responsible for food-poisoning outbreaks from undercooked ground beef), and is less likely to cause life-threatening kidney damage. However one patient from the Canadian outbreak did develop a kidney problem. Eleven of those who became ill reported that they “ate” or “probably ate” raw dough. 

What Happened in the U.S.

This outbreak echoes a similar one that occurred in the U.S. between December 2015 and September 2016, when 63 people in 24 states developed an E. coli infection after eating raw flour. And the CDC expects that more illnesses related to this outbreak will crop up because flour has a long shelf life. 

Unlike the Canada outbreak, the recent outbreak in the U.S. was caused by a potentially dangerous strain of E. coli called O121, which like E. coli O157 may cause abdominal cramps, bloody diarrhea, and kidney damage.

No one who became ill from flour or flour-based products died, but one victim suffered kidney damage and 17 other people were hospitalized. 

Products from a General Mills plant in Kansas City, Mo., that were produced in November 2015 are thought to have caused these E. coli infections. The company voluntarily recalled millions of pounds of possibly contaminated flour, including its Gold Medal, Signature Kitchens, and Gold Medal Wondra flour brands. Several cake and pancake mixes that may have included General Mills flour were also recalled.

The Food and Drug Administration and the CDC are still advising consumers not to eat flour and flour-containing foods that haven’t been cooked or baked. Consuming raw flour is a potential hazard, the FDA says; it isn’t meant to be a ready-to-eat product.

Some of the ways you can ingest uncooked flour may not be so obvious. Below are five sources of potentially tainted flour that you should watch out for if you want to avoid an E. coli infection.

1. Raw dough and batters. Cookie dough, pizza dough, and cake and pancake batters are risky, so you should be careful not to eat them before they’re cooked.

But raw dough can make you sick even if you don’t eat it. For example, kneading bread dough often leaves you with floury hands, which could be a problem if the flour is tainted. Some restaurants give children balls of uncooked dough to play with, and they might put the dough in their mouth or lick their fingers. Even storing uncooked dough next to other food could pose a risk, so be sure to handle and wrap it carefully.

2. Arts and crafts materials. Websites devoted to pantry-based projects offer recipes for modeling clay, playdough, spray glue, papier-mâché, and ornaments with flour as the main ingredient. For now, we recommend that you avoid making these mixtures with kids. 

3. No-cook dishes. Some recipes for truffles, icing, and cookies call for flour but don’t involve heating or baking. If the recipe doesn’t require the dish to be thoroughly cooked, skip it.

4. Contaminated cooking and eating surfaces. Flour is light and powdery, and can easily fly everywhere in your kitchen if you aren’t careful. Even minuscule amounts of tainted flour can make you sick, so be sure that foods that will be eaten raw don’t come into contact with flour-dusted counters, cutting boards, plates, and the like. Wash these—as well as your hands—in hot, soapy water after using them. Be careful if you’re dredging meat or chicken in flour before cooking; you don’t want the flour to go all over the place.

5. Containers you use to store flour. When you purchase a new bag of flour, you might dump the new flour into a bin or canister that has old flour in it, which might be tainted. If you’re not sure whether the old flour has been recalled, throw it out. Make sure that you thoroughly clean the storage container before using it again.