From stable to lab: a new plastic made from milk and hoof waste

by Sara MATTIELLO, Lucilla VERDECCHIA, Carlo SANTULLI, Cristiano FRAGASSA

Can a plastic be made from two biological scraps like spoiled milk and horse hoof shavings? The answer comes from an all-Italian research project that blends sustainability, ingenuity, and material science.

At its core lies the rediscovery of galalith — a “plastic of the past” made from milk casein and widely used between the 19th and 20th centuries for producing buttons, combs, eyeglass frames, and even piano keys. Today, this vintage bioplastic—long since fallen into disuse—is being reimagined with a modern twist: formaldehyde (once used to harden it) has been eliminated and replaced by natural reinforcements.

The new material is created by coagulating casein using vinegar, both derived from expired food products. Vinegar contains acetic acid, which has a plasticizing effect on casein. Keratin powder, sourced from another waste material—horse hooves, routinely trimmed during shoeing—is added as reinforcement. The result is a composite bioplastic with an ivory color and a horn-like consistency, showing greater hardness (Shore D ~40), lower porosity, and better impact resistance (2.3 KJ/m2) than the original galalith.

This bio-composite is designed for small stable items—such as hoof picks and mane combs—where its mechanical properties and durability can be demonstrated.

The project, named 'Milk Hoof', currently ongoing at the University of Camerino, aligns perfectly with the principles of circular economy: it reduces waste, adds value to discarded materials, and enables low-cost, local production of practical and customizable tools. A plastic born from waste, reborn as a resource: a tangible example of sustainable innovation.

* University of Camerino