Whole Foods is recalling a line of Organic Raw Almonds, due to elevated levels of a natural chemical, hydrogen cyanide, that could be fatal if consumed in high amounts, according to an announcement from the Food and Drug Administration.

The product, a bitter almond imported from Spain and Italy, is produced by Marin Food Specialties, Inc. of Byron, CA, who agreed to the voluntary recall. A naturally occurring chemical in the almonds commonly called hydrogen cyanide but known technically as glycoside amygdalin transforms into toxic prussic acid after an almond is crushed or chewed. Hydrogen cyanide is a natural component in peach and apricot pits. Almonds are a member of the same family.

“Eating foods that contain prussic acid may result in some or all of the following signs and clinical symptoms within minutes: dizziness, headache, nausea and vomiting, rapid breathing, rapid heart rate, restlessness and weakness,” according to the recall notice.

“Exposure to higher quantities of food containing prussic acid may cause other more serious health effects including convulsions, loss of consciousness, low blood pressure, lung injury, slow heart rate and respiratory failure leading to death.”

The USDA and the California Almond Board recommends against the consumption of untreated raw almonds, but for a different reason. The government introduced a “pasteurization” rule in 2007 in response to a string of salmonella outbreaks linked to large almond processing plants in 2001 and 2004; thirty-three people became ill, but no one died. Pasteurization is designed to kill microbial foodborne pathogens, which is why consumers are warned not to eat unpasteurized or raw almonds. However, the regulation does not apply to imported almonds, most of which, like the Whole Foods products, are organic.

According to the Almond Board, five methods of “pasteurization” are permitted: oil roasting, dry roasting, blanching, steam processing, and the use of propylene oxide (PPO). A sixth method involved irradiating the almonds, and this was used for a number of years, but now the Almond Board states that “Almond pasteurization does not include irradiation.”

Hydrogen cyanide is a chemical component and cannot be “killed” by pasteurization.

Many ‘natural health’ and organic activists–particularly those supporting GMO labeling–aggressively oppose, and even mock, any restrictions on the sale of raw almonds or pasteurization measures.

“[T]hirty-three people became ill, but no one died” from the salmonella incidents linked to raw almonds, the Alliance for Natural Health writes derisively on its website denouncing the USDA safety protocol. “Contrast that to the thousands of deaths caused by prescription drugs each year! …California’s Almond Board colluded with the USDA to propose mandatory ‘sterilization’ across the industry, and the USDA agreed to implement and enforce the new rule.”

The recall notice stressed the importance of monitoring symptoms: “Showing these signs and symptoms does not necessarily mean that a person has been exposed to cyanide. Treatment with supportive measures and available specific and efficacious antidotes frequently allows survival.”

The almonds were labeled as “Whole Foods Market Organic Raw Almonds Imported from Italy” and “Whole Foods Organic raw Almonds Imported from Spain” and packaged in 13.5 oz. plastic tubes. A complete list of Whole Foods stores where the product was sold can be found in the recall notification.

No illnesses or deaths have yet been reported.

Jon Entine, executive director of the Genetic Literacy Project, is a Senior Fellow at the World Food Center, Institute for Food and Agricultural Literacy, University of California-Davis. Follow @JonEntine on Twitter