To earn gluten-free certification under this program, companies must have a gluten-free compliance plan and undergo onsite inspections of their production and handling facilities. During the onsite audit, accredited inspectors collect a random sample of each product for testing to confirm gluten-free integrity of 20 parts per million (ppm) or less. In addition, the inspector verifies that the company is conducting the appropriate raw ingredient testing or that raw ingredients are being sourced from an NSF International certified gluten-free supplier. The onsite audit requirement also helps verify that product manufacturers and handlers have procedures to prevent contamination and commingling, which is critically important for those with gluten allergies and gluten-intolerance. Like with all NSF International certification programs, monitoring for ongoing compliance with the standard is an essential part of certification and includes annual manufacturing facility inspections and product testing.