Shellfish Allergen Control: Understanding Crustaceans and Mollusks in Food Processing

Shellfish are among the Big 9 allergens identified by the   U.S. Food and Drug Administration (FDA), requiring strict labeling and control to protect allergic consumers. Unlike many food allergies that begin in childhood, shellfish allergies often develop later in life and can be severe or lifelong. According to FARE, 60% of people with a shellfish allergy experience their first allergic reaction as an adult. For food manufacturers, this means even trace contamination can lead to serious health risks, costly recalls, and regulatory action.

To minimize those risks, companies must look to implement strong allergen control in food processing environments. Under the Food Safety Modernization Act (FSMA), allergen control is recognized as a key preventive control requirement which means processors must verify that cleaning, testing, and labeling programs effectively minimize cross-contact risks. Understanding the differences between crustaceans and mollusks, as well as the proteins that trigger allergic reactions is key to building effective allergen management programs and helping ensure food safety compliance.

Understanding Shellfish Allergens 

 The term shellfish covers two biologically distinct groups: crustaceans (such as shrimp, crab, and lobster) and mollusks (such as clams, oysters, scallops, and mussels). Despite their differences, both groups share a major allergenic protein called tropomyosin, which plays a role in muscle function.

Because of this shared protein, individuals allergic to one type of shellfish often experience cross-reactivity with the other. Even small amounts of shellfish residue can cause severe allergic reactions, making proper shellfish allergen testing and verification essential. Recent FDA seafood recall data shows that undeclared allergens are the leading cause of seafood-related recalls, accounting for 34% of incidents between 2002 and 2022 (Blickem et al., 2023).

For processors, understanding these allergenic components provides the foundation for prevention, cleaning, and testing protocols that protect consumers and brands alike.

Crustaceans vs. Mollusks: Key Differences

Recognizing these distinctions helps QA and FSQA teams determine appropriate allergen control in food processing, ensuring that each allergen type receives the proper level of attention and testing.

           Source: FDA – Food Allergies, Food Allergy Canada – Crustaceans & Molluscs, Food Allergy Research &  Education – Shellfish

Allergen Cross-Contact Risks in Food Processing

Cross-contact can occur when shellfish proteins unintentionally transfer onto non-allergenic products or surfaces. In food processing, even trace contamination can compromise an entire batch.

Common risk points include:

• Shared processing equipment or tools
• Ineffective sanitation between product runs
• Improper handling of raw materials and rework
• Airborne particles or water splash during production

To reduce these risks, implement a documented allergen cross contact prevention program that includes:

• Scheduling production runs to separate allergen-containing and allergen-free products
• Using dedicated tools, containers, and utensils where possible
• Conducting visual inspections and verification testing post-cleaning
• Training employees on allergen awareness and correct sanitation procedures

FSMA regulations require documented preventive controls for major allergens, and proactive monitoring helps demonstrate compliance.

The Role of Allergen Detection

Even the best prevention programs need verification. Routine shellfish allergen testing can help ensure your cleaning and control measures are working as intended.

Testing can occur at multiple points in production:

• Environmental monitoring helps detect residues on equipment or surfaces after cleaning.
• Ingredient verification helps ensure that suppliers are providing accurately labeled inputs.
• Finished product testing helps reduce the risks of allergenic protein presence in food.

Crustacean Allergen Testing Solutions 

Neogen provides a comprehensive portfolio of allergen detection tools that help processors verify cleaning effectiveness and support regulatory compliance.

The Reveal® for Crustacean Allergen test offers:

• Rapid results for on-site verification
• Screen swab or clean-in-place rinses
• Reliable performance aligned with industry standards

Veratox for Crustacean Allergen test offers:

• Laboratory-grade ELISA kit
• Screen food products, ingredients, environmental swabs, and clean-in-place rinses
• Quantitative sensitivity to measure trace levels of crustacean allergen

These solutions are designed to integrate seamlessly into allergen management programs, empowering food manufacturers to make confident, data-driven decisions.

To learn how Neogen’s allergen testing portfolio can help you strengthen your allergen control program, contact our experts!