Coatings offer enhanced functionality

Food and beverage packaging protects food from microorganisms, makes storage easier, and prolongs the shelf life of its contents, ultimately safeguarding the consumer. But many food contact materials used for packaging are not fit for purpose in their raw state. For instance, Paper and Moulded Fibre are porous and have poor barrier properties if left untreated, while a metal can is susceptible to corrosion and could interact with its contents. When a substrate is coated, it gains enhanced functionality, such as resistance to oxygen, water, or oil transmission, or anti-corrosive properties. The ideal type of coating for your use case will depend on a number of factors: the substrate, the type of food or drink contained within it, the temperature at which it will be stored, and the duration of storage.

Coatings are regulated

Different regions have varying regulations governing the composition and use of coatings. In 2004, the European Union passed Article 3 of the Framework Regulation (EC) No. 1935/2004, laying out an inertness criteria and a set of consumer safety requirements for food contact materials (FCMs), including coatings. In the US, FCMs are governed by the Code of Federal Regulations under Title 21 on Food and Drugs. A key divergence between European and American regulations is that the latter focuses on exposure, whereas the former is concerned with migration. Clearly, there's ambiguity on the matter, so find out which regulations apply to you before exploring your options. To future-proof your brand, however, we recommend acting on as many regulatory stipulations as possible, regardless of region, as history tells us legislation morphs and adapts over time.

Plastic-based coatings are harmful

The industry standard for aluminium can coatings typically contains BPA, or bisphenol A, to reduce corrosion, prevent contamination, and extend the contents' shelf life. According to the European Food Safety Authority, "BPA can migrate in small amounts to food and beverages stored in materials containing the substance", and given that it's considered an endocrine-disrupting chemical, it is somewhat baffling that regulatory bodies such as the Food Standards Agency maintain that "dietary exposure to BPA is not a health concern". Meanwhile, a number of European countries, including France and Spain, have placed an outright ban on BPA in food contact materials. Emerging studies are increasingly pointing to the harm that BPA-coated food and drinks cans may be having on human health – the chemical has been linked to everything from anxiety and depression, to diabetes and heart disease. Likewise, paper coffee cups — which are usually lined with polypropylene (PP), polyethylene (PE), or polyethylene terephthalate (PET) to offer a barrier to moisture — have been shown to leach up to 1,489 microplastic particles per cup. Exposure to microplastics has been linked to DNA damage, inflammation, and oxidative stress. Understanding the gravity of the problem will empower you to find a solution.

Coatings can hinder end-of-life possibilities

Sustainable materials that are finished with non-soluble or plastic-based coatings will be difficult, if not impossible, to repulp and recycle once they're discarded. A recyclable material coated in a plastic or chemical coating is effectively deemed a single-use item that can't be repurposed — a differentiation that can’t be overlooked in light of emerging Extended Producer Responsibility laws. The coating you choose for your packaging is therefore critical, as it could compromise the inherent biodegradability and recyclability of materials like paper and moulded fibre.

Recently, water-based or aqueous coatings — which can be dissolved or washed off the substrate during the remanufacturing and recycling process — have been increasingly touted as a solution. But they still use toxic plastic materials, often microparticles of polyacrylate and polystyrene. When they're washed off or the packaging is repulped, microplastics end up in our water streams, making a bad situation even worse. The industry's efforts to endorse these coatings as recyclable, and the use of the term 'water' – deemed harmless by most – appears to be more of a greenwashing tactic than a green solution, so approach every coating with caution.

Bio-based alternatives are emerging

As public awareness continues to grow about the potential health and environmental effects of plastic coatings, the search for bio-based alternatives is picking up pace. Companies such as Notpla Coating are exploring plant-based options derived from Cellulose and Seaweed. A team of European researchers has gone as far as developing a bio-based lacquer for metal food packaging made from tomato pomace, which has shown promise after exhibiting good anti-corrosive properties against salt and liquids. An 'anti-packaging' trend is also on the horizon, where edible coatings such as Apeel and NatuWrap are applied directly onto fresh fruit and vegetables, eliminating plastic wrappers and containers, and minimising food waste due to spoilage. While many of these solutions are still in their infancy, you can support the movement by establishing partnerships and conducting trials to transform them into fully fledged formulas.