National Sanitation Foundation, is a not-for-profit, non-governmental organization that provides stan- dards, certification, education, and risk management services in the fields of public health safety and the environment. NSF was founded in 1944 in response to a need for a single set of food equipment sani- tation standards that manufacturers and operators could accept and regulators could adopt into code. NSF has 21 standards for all types of products and materials used in food service. The standards contain requirements for materials, design, construction, and performance of food service equipment to ensure that it is safe and can be kept sani- tary. Today, NSF Food Equipment Standards are globally recognized, and certification to the standards is required by regulators, specified by end users, and marketed by manu- facturers. 6.2 NSF Material Requirements – Standard 51. An important com- ponent of the NSF Food Equipment Standards is the material require- ments. While each standard can have its own unique mate- rial requirements, all food equip- ment standards reference NSF/ ANSI Standard 51-2002, Food Equipment Materials. The material requirements help to ensure that only nontoxic and cleanable mate- rials are used. Material suppliers have utilized NSF Certification to Standard 51 as an effective meth- od for marketing their products to food equipment manufactur- ers. Manufacturers who purchase NSF-certified materials have one less item of concern when getting their own equipment certified. 6.3 Applying Standard 51 to Natural Stone. When reviewing granite, marble, and other natural stones to the requirements of Standard 51, there are essentially two issues that can determine its accep- tance: smoothness and toxicity. 6.4 Smoothness. The standard defines “smooth” as free of surface imperfec- tions that are detect- able by visual or tac- tile inspection. This includes pits, cracks, and crevices. This concern for smooth surfaces applies not STONE ––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– Photo courtesy of Rugo Stone 82 TileLetter | July 2019