More than 80 percent of the spices that make their way into American kitchens come from overseas because most spices require a tropical or subtropical climate to grow, other than onion, garlic, some chilies and mustard seed. And because many spices are grown and processed in developing countries, food safety and handling processes aren’t as stringent as they are in the United States.

Further, because spices are grown outdoors, they are likely to pick up animal hairs, insects and other contaminants that are an unavoidable part of the growing process. Because heat and other treatments commonly used to eradicate bacteria in spices will not work to eliminate these contaminants, spice processors continue to struggle with ways to deal with filth contamination in spice shipments.

Spice vendors have argued that spices are further treated upon arrival in the United States as part of the packaging and distribution process, implying that spices distributed to food stores aren’t dangerous or contaminated.

What Happens When Contamination Is Found?

The United States has the right to refuse spice shipments with potentially dangerous contaminants that come to the United States. In 2013, for example, FDA inspectors turned away 906 shipments of spices because of filth or the presence of Salmonella.

During this study, though, it became clear that contamination isn’t always happening before spice shipments pass through customs. In one case outlined in the FDA’s Risk-Safety Assessment, a shipment of whole white peppercorns at a California spice processing facility that had been unopened since import was found to contain Salmonella, which would suggest that the contamination took place in Vietnam, the bag’s country of origin. These spices had been “steam washed” to clean the peppercorns but hadn’t undergone any effective pathogen reduction treatments. Inspectors were surprised, however, to find that the lot this bag was a part of came with a certificate of analysis (COA) that stated that the lot had been tested prior to import and had tested negative for Salmonella.