Cross-contact

Cross-contact is the unintended transfer of a small amount of an allergen or gluten from one food into another — through shared equipment, utensils, hands, or airborne flour. In allergen and gluten-free work the term is preferred over cross-contamination, which usually refers to microbes. Even trace cross-contact can push a product over a gluten-free threshold, so controlling it is central to the claim.

In depth

The two terms describe different hazards. Cross-contamination generally means microbial transfer — bacteria moving between foods. Cross-contact means allergen or gluten protein moving between foods. A product can be microbiologically safe yet still fail an allergen or gluten-free check because of cross-contact.

On a shared line, cross-contact happens through residues on equipment, shared scoops and tools, rework, or flour dust in the air. Controls include scheduling allergen-free runs first, validated cleaning between runs, dedicated equipment and segregated storage.

For a gluten-free claim the stakes are measured in parts per million: the finished product must stay under 20 ppm of gluten, so a review examines cleaning validation and testing that demonstrate cross-contact is kept low — see ALARA.

Related marks

• Gluten-FreeNot built for retailers mandating GFCO specifically — if yours does, we'll tell you before you pay anything.

Related terms

• Allergen — A food allergen is a substance, usually a protein, that can trigger a harmful immune response in sensitive people and must be declared under labeling law.
• Gluten — Gluten is a group of storage proteins found in wheat, barley, rye and their crosses, which some people must avoid for medical reasons.
• Parts per million (ppm) — Parts per million (ppm) is a unit for very small concentrations, equal to one milligram of a substance per kilogram of product.

Frequently asked questions