Chemical hazards are chemical substances that are either naturally present in food or added intentionally or unintentionally. A chemical is considered naturally present if it is a normal component of the plant, animal, or microorganism. For example natural toxins are present in or produced by certain mushrooms, shellfish, molds and bacteria. Intentionally added chemicals may include pesticides, fungicides, insecticides, herbicides, growth hormones, antibiotics, allergens, preservatives and coloring agents used to facilitate food production and processing. The FDA enforces action levels and tolerances on a range of unavoidable poisonous substances, pesticides and food additives to protect public safety. Unintentionally added chemicals are chemicals that may inadvertently be incorporated in food during production and processing. For example, failure to apply the correct concentration of pesticide on crops; harvesting too soon after pesticide application; failure to properly rinse chemical residue from food contact surfaces after cleaning operation; storing harmful chemicals next to food ingredients; and application of rodent baits in areas where food is bring processed or stored.
Controlling Naturally Occurring Toxins
You can control the levels of naturally occurring substances in your raw material by establishing supplier controls. This can be done by requesting letters of guarantee and certificates of analysis (COA) from your supplier to assure and verify that toxins are absent or within the acceptable regulatory limits. Verifying that shipping and storage containers are maintaining the right cold temperatures is essential for seafood since they can produce high levels of scrombotoxin if temperature-abused. Dry ingredient containers should be checked for evidence of wetting and mold, which could result in development of aflatoxin. Moisture, water activity and aflatoxin tests may be carried out prior to accepting shipment of grains. Maturity of produce may play a role in your decision to accept them in your plant for processing since they may have high concentration of natural toxins. For example, immature potatoes will have a high level of a poison called solanine. Some natural toxins, for example cyanogenic glycosides in cassava can be controlled by proper extraction and heat processing.
Controlling Pesticides
Incoming raw materials may have higher than normal pesticide residue due to indiscriminate and disproportionate application on the farm. Requesting letters of guarantee and certificates of analysis can be used as strategies to control the amount of pesticide residues that you can accept. You may also periodically sample and analyse raw materials for hazardous chemicals to verify that they meet the allowable legal tolerance.
Controlling Allergens
Allergens are proteins that trigger an allergic immune response which may include fainting, lightheadedness, low blood pressure, dizziness, mental confusion, difficulty breathing, skin rash, itching, swelling, nausea, and vomiting. About 90% of all allergic reactions are caused by the “big eight” allergens i.e. soy, peanuts, tree nuts, egg, milk, wheat, fish and shellfish. To prevent contamination with allergens, you should process non-allergen foods on your equipment before you process foods that contain allergens. Allergens must only be processed on equipment that are designed to facilitate proper cleaning and inspection. After processing you should thoroughly clean the equipment to remove allergen residue. A good idea is to implement a lockout procedure for equipment that contain these residues. In that way you can prevent the equipment from being used until proper cleaning is done. You may also establish traffic patterns in your plant to prevent allergens from entering allergen-free areas. Make sure to label foods containing allergens clearly and accurately to indicate that they “contain” or are derived from a major food allergen.
Controlling Food Additives
Approved food additives can be hazardous if their portions in product formulations exceed allowable limits. To avoid this, keep proper logs of batching activity including name of ingredients, weight added, date and time added. Practice to conduct periodic verification of batch logs.
Controlling Cleaning Chemicals
Only accept chemicals in your facility that are properly labeled and have regulatory approval. Inspect the delivery truck for physical evidence of damage to package, spills and odors. Hold or reject shipment that may have resulted in cross-contamination of chemicals with food. Store all chemical substances in a manner that will prevent contamination of food and packaging materials. Hold hazardous chemicals in a physically separate enclosure, accessible only by authorized personnel. Also, use chemicals according to the established standard operating procedures for mixing and safe application.
Controlling Poison Baits
Never apply poison baits in areas where food is being processed or stored. Instead they can be safety installed in stations at the outside periphery of the building. Whether or not you do your own pest control or contract the activity out to a certified pest control operator (PCO), you should keep a proper record to provide evidence of chemicals used, when they were used, quantity used, where and how they were applied.
Reference: Scott, V. N. & Stevenson, K. E. (2006). HACCP – A systematic approach to food safety, 4th edition. Washington, DC: Grocery Manufacturers Association.
