The document discusses allergens and food allergies. It defines an allergen as a harmless substance that causes the immune system to mistakenly launch an attack. Common allergens include dust mites, pollen, pet dander, royal jelly, peanuts, tree nuts, wheat, soy, milk, eggs, fish and shellfish. Another type of allergen is urushiol, a resin from poison ivy and oak that causes a skin rash. Symptoms of allergies can range from mild to severe or life-threatening anaphylaxis reactions. Proper food handling techniques like handwashing and using color-coded cutting boards are important for food service workers to avoid cross-contamination