The most important chemical hazard for peanuts is aflatoxin, which is produced by fungus that can grow on some crops. The fungus, A. flavus, is more prevalent in the field when crops are exposed to water stress, high temperature stress, insect damage, poor fertility or weed competition. After harvest, warm temperatures and high humidity can increase the risk of A. flavus growth and aflatoxin contamination.
The health effects from exposure to aflatoxin can be both long term and acute. Acute symptoms include vomiting, abdominal pain, pulmonary edema, convulsions, coma, cerebral edema, liver, kidney, or heart involvement that can lead to death. Long term lower-level exposure can lead to liver cancer.
Recommendation for the prevention and reduction of aflatoxin contamination in peanuts can be found in Codex CAC/RCP 55-2004. This is an excellent resource for best practices for pre-harvest, harvest, transport, segregation, storage, shelling, sorting, blanching, and packaging activities.
A food allergen is a food that causes an adverse physical response in individuals that are sensitive to the particular proteins in the food. The response can vary from mild to life threatening. A miniscule amount of the protein allergen can trigger symptoms. Undeclared food allergens represent a large percentage of product recalls in the United States.
Major Food Allergens Milk Egg Peanut Tree nuts Fish Crustacean Shellfish Wheat Soy
Food Allergy Symptoms Swelling and tingling of lips, mouth or tongue Cramping, vomiting, diarrhea Hives, eczema Wheezing, coughing, swelling of throat Loss of blood pressure Anaphylaxis -- most dangerous, life threatening
Since peanuts are one of the major food allergens, peanut product manufacturers must recognize peanuts in their food safety plan as an allergen hazard and manage preventive controls accordingly.
Chemicals can make their way into food unintentionally. Cleaning and sanitizing chemicals are necessary to maintain a sanitary environment to produce food products and small amounts of sanitizers may remain on equipment surfaces. It is important to follow label instructions to ensure they are used safely.
Pesticides and herbicides
Pesticides and herbicides can be applied directly crops to control weeds and insects. Some pesticides, such as those to control rodents, cannot be applied directly to food. Pesticides should be registered with appropriate authorities and used only according to label instructions. Only pesticides approved by local authorities for specific use on peanuts should be used. Pesticides must be applied properly – within specified tolerance levels – to ensure that any amount of residue left on food is safe.
Heavy metals are chemicals that may accumulate in fish or plants if the growing environment has high concentrations of these chemical hazards. Most countries have standards for the maximum level of heavy metals allowed in foods. Heavy metals found in peanuts include mercury, cadmium, lead, and arsenic. A producer needs to be aware of the limits for countries in which they intend to market their peanuts. A chart of these limits is available from the American Peanut Council.