Formulators Forum—Formulating Powder Coatings for Use on Food Equipment

Food contact materials (FCM) are materials that are in contact with food or potable beverages during processing, packaging, or storage. During contact, molecules from FCM can migrate into foods or beverages. Because of this, most countries have food safety regulatory agencies that monitor materials for food safety. Manufacturers of food equipment and components such as shelving, broilers, beverage dispensers, cutting boards, stock pots, tubing, sealants, gaskets, valves, food service backsplashes, refrigerated storage parts, and display cases seeking to obtain NSF certification are required to use NSF/ANSI 51 approved coatings. NSF International, formerly known as the National Sanitation Foundation, is a globally recognized organization that creates independent standards and product testing programs pertaining to food safety and sanitation to improve overall public health. NSF/ANSI 51 establishes the minimum requirements for materials used in the construction of commercial food equipment. It is closely related to the NSF/ ANSI 61 standard, which deals with the requirements for the chemical contaminants and impurities that are indirectly imparted to drinking water from products, components, and materials used in the public potable water supply.

The NSF/ANSI 51 requirements are intended to ensure that the composition and surface finish of food equipment will not adulterate food nor render food equipment difficult to clean and sanitize. The formulation requirements are based on compliance with U.S. Food and Drug Administration (FDA) Code of Federal Regulations (CFR) Title 21. Other relevant requirements apply to the finished product and include cleanability, coating adhesion ability, as well as resistance to corrosion, abrasion, impact, and heat. The most current version of this standard was published in September 2023, with major updates made to lead content requirements.

The standard can be used to classify equipment into zones based on their contact and exposure to food. Different types of handling and serving equipment have different certification criteria. Food zone, which has the strictest certification requirements, refers to surfaces with direct contact, including those where food or condensate may contact then drip, drain, or splash back into food or onto surfaces that are intended to be in direct contact with food (nondirect food contact).

Splash zones are areas or surfaces that do not come into direct contact with food yet become soiled due to spills and splashes when equipment is in use. Non-food zones are neither in the food zone nor in the splash zone, i.e., are not exposed to food or food spills.

Powder coatings have been used in the marketplace for over 30 years because they are environmentally compliant and provide a very durable and sustainable option that can meet the NSF/ANSI 51 standard. Many colors are approved for use in the industry, from greens, blues, reds, and yellows; to white, grey, and black, including metallics. Formulating compliant powder coatings for food contact surface finishes must comply with the FDA’s raw materials requirements of 21 CFR 175.300 Resinous and Polymeric Coatings. This regulation specifies coatings that may be safely used for food contact surfaces of items intended for use in producing, manufacturing, packing, packaging, treating, transporting, or holding food, when the coating is applied as a continuous film over a metal substrate, or when the coating is intended for repeated use and is applied to any suitable substrate as a continuous film or enamel, serving as a functional barrier between the food and the substrate. Epoxy, polyester-epoxy hybrid, and polyester-HAA are the typical resin systems used for NSF/ANSI 51 compliant coatings. The pigments used should also conform with the requirements of 21 CFR 178.3297 Colorants for Polymers.

Other additives or ingredients are regulated by FDA 21 CFR 174, Indirect Food Additives: General, FDA 21 CFR 177, Indirect Food Additives: Polymers, FDA 21 CFR 178, Indirect Food Additives: Adjuvants, Production Aids, and Sanitizers, and FDA 21 CFR 181, Prior-Sanctioned Food Ingredients. The formulated powder should also not contain lead, arsenic, cadmium, or mercury as intentional ingredients.
Unintentional lead content (lead impurity) greater than 0.06% shall not be used.

Upon formulation review by NSF, performance testing can be done depending on the end use of the product. NSF/ANSI 51 certified products can be found at www.nsf.org/certified- products-systems including food contact type restrictions (direct/non-direct) and maximum temperatures for certified materials.

Although additional steps may be required during the application process, utilizing powder coatings that adhere to NSF/ANSI 51 standards ensures a higher level of safety for a wide range of products. This compliance is particularly critical in the food service industry, where consumer health and business reliability depend on durable, non-toxic, and easy-to-clean finishes that meet stringent safety and hygiene requirements.

Jeliza Bonso is segment leader II with TCI Powder Coatings.