The surfaces are coated with paints or enamels.
The functional characteristics of a coating intended for direct food contact ensure the isolation of the base metal from the food, resistance to mechanical processing, chemicals and natural or added components of the food, and the necessary inertness to the food itself.
The most commonly used paints and enamels are a mixture of:
- resins (epoxy, polyester, epoxy ester, acrylic, vinyl, ketone, etc.)
- cross-linking agents (melamine resins, urea resins, benzoguanamine resins, phenolic resins, trimellitic anhydride isocyanates)
- solvents (aromatics, ethers, glycols, acetate glycols, acetate heteriglycols, ketones, mineral ragies, alcohols, etc.)
- water and aliphatic amines (in the case of water-dilutable products)
- additives (substrate and surface wetting agents, lubricants, etc.)
- catalysts
- pigments (inorganic, organic and metallic)
- functional fillers (zinc oxide and carbonate, polyvinyl chloride)
In addition, the monomers required for the preparation of base polymers (resins) and crosslinkers must be present in the various positive lists contained in the laws regulating the subject at European and national level. These are mainly:
- EC Reg. 1895/2005 on the restriction of the use of certain epoxy derivatives for MOCA. It also defines the migration limit of certain epoxy derivatives in plastics or protected by a surface coating
- EU Reg. 10/2011 on plastic materials and articles intended to come into contact with foodstuffs
- EU Reg. 2018/213 on the use of Bisphenol A (BPA) in paints and coatings intended to come into contact with food.
In addition to the product-specific requirements aimed at guaranteeing its performance, economic operators must draw up a Declaration of Conformity in order to have MOCA certification in accordance with Reg. 1935/2004, in order to guarantee the traceability of the products used (paints and enamels included). The declaration must comply with Annex I of EU Reg. 2018/213.
Furthermore, should its composition include an epoxy resin base, compliance with EC Reg. 1895/2005 must also be mentioned, and the composition must not contain Bisphenol A.
