Guidance Level for Brevetoxins in French Shellfish

Area of Science:

• Marine biology
• Food safety
• Toxicology

Background:

• Brevetoxins (BTXs) cause neurotoxic shellfish poisoning (NSP) with neurological, gastrointestinal, and cardiovascular symptoms.
• The dinoflagellate *Karenia brevis* is a primary BTX producer; other microalgae may also produce BTX-like compounds.
• BTXs are not currently regulated in France or Europe, but were first detected in French mussels in 2018.

Purpose of the Study:

• To establish a guidance level for brevetoxins (BTXs) in shellfish in France.
• To address the public health risks associated with BTX-contaminated shellfish consumption.
• To inform regulatory actions by proposing a safe level for BTXs in seafood.

Main Methods:

• Review of toxicological data and human case reports of BTX exposure.
• Identification of lowest-observed-adverse-effect levels (LOAELs) from available human data.
• Calculation of a proposed guidance level based on LOAELs and a default shellfish portion size.

Main Results:

• Insufficient toxicological data precluded deriving an acute oral reference dose (ARfD).
• Two lowest-observed-adverse-effect levels (LOAELs) were identified from human case reports.
• A guidance level of 180 µg BTX-3 eq./kg shellfish meat was proposed.

Conclusions:

• A guidance level for brevetoxins in shellfish is proposed to mitigate health risks in France.
• The proposed level of 180 µg/kg accounts for a 400 g shellfish portion.
• This initiative supports the monitoring and management of marine biotoxins in seafood.