How are heavy metals controlled in marine collagen peptides?

Beyond Biopharma | Collagen Peptide FAQ

Short answer: Heavy metals in marine collagen peptides are controlled by sourcing fish skin and scales from defined fishing areas with traceable species, by washing and purifying the raw material before hydrolysis, and by testing every lot for lead, cadmium, mercury and arsenic against an agreed specification. Results are reported on the supplier certificate of analysis, so the buyer can see the actual figures for the lot rather than a general statement.

Why marine raw material deserves attention

Fish skin, scales and bones are the tissues most often used for marine collagen peptides, and they sit in direct contact with seawater and with the animal's own mineral metabolism. Trace metals that are present in the marine environment can therefore accumulate in these tissues over the life of the fish, and the level varies with species, age and size, the part of the fish used, the fishing ground and the season. This does not make marine collagen peptides a high-risk material - well controlled material is routinely supplied with low parts-per-million or parts-per-billion figures - but it does mean the control strategy has to begin upstream rather than at the finished powder.

Step one: raw material selection and traceability

The strongest control is the choice of raw material. Suppliers that work from defined fishing areas, with known species and documented landings, can show where each batch of skin or scale came from. Selecting smaller, younger fish, avoiding species known to accumulate mercury, and separating material by origin and landing date all reduce the variability that makes testing difficult to interpret. Traceability at this stage turns a heavy metal result into a trend rather than a surprise.

Step two: process steps that reduce metals

• Washing and rinsing - repeated clean-water washing removes surface contamination, sand and loosely bound material before hydrolysis.
• Demineralisation - scales and bone-rich material are commonly treated to remove mineral matter, which also carries away part of the associated metal load.
• Filtration and clarification - fine filtration and clarification steps remove particulate material that can carry metals into the finished powder.
• Adsorption and ion exchange - where a specification is tight, treatment with adsorbents or ion exchange resins can further reduce dissolved metal ions.
• Dilution and blending - blending lots to a target value is common practice, but it should be supported by testing of the blended lot, not only of the components.

Step three: testing and specification

Heavy metals should be reported individually, because lead, cadmium, mercury and arsenic behave differently and are regulated differently. Inductively coupled plasma mass spectrometry (ICP-MS) is the usual technique for trace levels, with atomic absorption or ICP optical emission also used. Two practical points matter when you read a report: whether results are expressed on a dry basis or as received, and whether arsenic is reported as total arsenic or with inorganic arsenic speciated separately, since the toxicity and the regulatory limit differ. Limits are set by the destination market and the intended use, and the certificate of analysis should show the limit, the method and the measured value for the lot.

Testing frequency and what a buyer should verify

Some specifications require heavy metals on every lot, others allow a fixed testing frequency with periodic verification. Both approaches exist, but the risk profile of the material and the claim on the finished label should drive the choice, and a per-lot result is the most defensible. When you qualify a marine collagen peptide, ask for the specification with limits, a certificate of analysis for the lot you are receiving, and information on the origin of the raw material. Independent verification of the first lots through an accredited laboratory is a normal part of qualification.

Keeping control through the finished product

Heavy metal control does not end at the ingredient. A finished product that carries a meaningful dose of collagen peptide inherits the concentration of that ingredient, and other components such as plant powders, cocoa, marine oils and mineral salts bring their own contribution. Assessing the total intake per serving against applicable limits, and holding the ingredient specification at a level that leaves room in the formula, is the practical way to keep a finished product inside its market requirements.

Related reading

For more detail, see the specifications that appear on a collagen peptide COA, the applications collagen peptides are used in and their use in clinical and senior nutrition.