cheerios recall
Cheerios recalled 1.8 million boxes of cereal Monday. Find out if you're affected and how to get a refund. Getty Images

General Mills issued a recall Monday for 1.8 million boxes of Cheerios that were advertised as gluten-free but were in fact cross-contaminated with wheat. Here's how to find out if your cereal was one of the many boxes made at a California factory in July that puts people with gluten allergies or celiac disease at risk. Only people with these allergies can be affected, and people without allergies do not have cause for concern, as nothing is toxic in the cereal.

The boxes recalled included both regular Cheerios and Honey Nut Cheerios made during a two-week period in Lodi, California. In a statement announcing the voluntary recall, General Mills assured consumers that it was an isolated incident that "allowed wheat flour to enter our gluten-free, oat-based system."

Consumers must check the "best by" expiration date on their cereal to see if they have been affected. For Honey Nut Cheerios, any box created between July 12-25 in the California factory could be contaminated. Those boxes are identified by the label 12 July 2016 LD-25 July 2016 LD. For regular Cheerios, any box created between July 14-17 could be cross-contaminated and is identified by the label 14 July 2016 LD-17 July 2016 LD. For a more detailed explanation, see Cheerios explanation posted to its Twitter:

If your box was contaminated, you are entitled to a full refund or a replacement box. General Mills has advised customers to call this number to request their refund: 1-800-775-8370.

"We care about what you and your family eat, and we are truly sorry for this mistake," read the apology posted to Cheerios' verified Twitter account Monday, adding, "We will work extremely hard to earn back your trust."