Definition of a natural coating:

A coating made from naturally occurring materials such as plants, animals, microorganisms or minerals. Natural coatings can be created through physical processes, natural fermentation reactions or other chemical processes.

What are natural coatings?

A coating is a substance applied to a surface (or ‘substrate’) to enhance its performance or aesthetic properties. Examples of coatings include paints, leather treatments and the ‘silvering’ used to make mirrors. A natural coating is a coating that is made from naturally occurring materials. These can be derived from plants, animals, microorganisms, or minerals.

How are natural coatings made?

They can be made using physical processes (e.g. milling, drying or distillation), naturally occurring fermentation reactions (resulting in molecules that occur in nature) or other chemical processes (e.g. extraction using solvents). Natural coatings are produced without any intentional chemical modification.

What are natural coatings made from?

Naturally derived ingredients are ingredients that are over 50% of natural origin, by molecular weight. Ingredients derived from petrochemicals are not considered natural by this definition. Examples of natural coatings include paints made from linseed oil, polysaccharides (such as cellulose, starch, dextrin, chitosan and other gums), proteins (such as gelatin, gluten and casein) and waxes (such as shellac, carnauba wax or beeswax).

What are natural coatings used for?

Natural coatings are commonly used on food products to prevent moisture loss and bruising during shipping. They were also formerly used in leather processing but have since been replaced by synthetics such as polyurethanes and polyacrylates. However, natural coatings are making a comeback in leather processing thanks to innovations that combine durability, performance and end-of-life biodegradation.

What are the advantages of natural coatings?

Replacing artificial or fossil-based coatings with natural ones can improve the biodegradability of materials. This helps to reduce the environmental impact of products over their lifetime. It also helps to reduce reliance on fossil resources, thereby lowering the carbon footprint of materials.

What are the challenges of natural coatings?

Some natural coatings are less stable than man-made or fossil-based alternatives. This means they are less suitable for certain applications, such as waterproofing. However, the next generation of natural coatings is already being developed. For example, there is now a leather coating made from fungal strains that has a waterproofing effect.

What is the future of natural coatings?

As products’ end-of-life becomes more of a concern for customers and regulators alike, using natural coatings is a key strategy for reducing the environmental impact of materials. Through EU-funded projects like BioNIPU and CHAMPION, Stahl is partnering with private companies and research institutes to drive innovation in natural coatings.

Not done learning today?

Explore our Beyond Chemistry pages to learn more about anything from hybrid polymers to bio-based (carbon) content measurement.