The Milk allergen in Taco Bell's Sausage and Cheese Biscuit Taco is present mainly in the cheese and biscuit components of the meal. It might pose a risk to individuals with lactose intolerance or a milk allergy.

The allergen Wheat present in Taco Bell's Sausage and Cheese Biscuit Taco mainly comes from its biscuit base and potentially the sausage. This allergen can cause reactions in individuals with a wheat allergy, gluten intolerance, or celiac disease.

Soy is a common allergen that can be found in Taco Bell's Sausage and Cheese Biscuit Taco. It is used in various forms in their ingredients and can cause allergic reactions in people sensitive or allergic to it.

Egg allergen in Taco Bell's Sausage and Cheese Biscuit Taco refers to proteins present in eggs used in the preparation of the food item. This allergen could be present in the biscuit, sausage, or cheese filling, posing a potential risk to individuals with egg allergies.