WASHINGTON — Hundreds of products are being pulled from store shelves after traces of peanut were found in cumin spice — a life-threatening danger to some people with peanut allergies.

The recall has been ongoing since December, as more retailers identify products that contain the cumin.

The Food and Drug Administration is now warning all people with peanut allergies to avoid cumin and products that contain cumin.

While such large allergy-related recalls are rare, undeclared allergens like peanuts are the leading cause of food recalls in the United States. That can be very unsettling to people who are keeping a close watch on what they or their children eat.

“You might do all of the things you are supposed to do and read the label, but there could still be undeclared allergens,” said Dr. Michael Pistiner, a Boston-based pediatric allergist. “It’s challenging to know that and still feel comfortable.”

Pistiner said he sees the recalls as low-risk, since often the amount of the undeclared allergen is very small. “But the highest risk is to our comfort,” he said.

According to the group Food Allergy Research and Education, 15 million Americans have food allergies, including 1 in 13 children. Eight foods account for more than 90 percent of the allergies — peanuts, tree nuts, milk, eggs, wheat, soy, fish and shellfish.

Since 2006, those allergens are required by law to be listed on food packages if they are ingredients. The law is less clear when it comes to cross- contamination, however — companies aren’t required to list on the label if peanuts or another allergen are processed in the same facility or on the same equipment.

Little is known about how many people may have reactions to allergens that accidentally make their way into food.

The FDA said it had 428 reports of “adverse events” related to undeclared allergens between January 2012 and December 2014, including reports of three deaths. The agency would not release any detailed information on those reports, which are made by consumers and can’t always be confirmed by the agency.