I worked for over 20 years for a major food manufacturing company that built 90% of their processing and packaging machines inhouse. Any fasteners used in or near a food contact zone, or in a heavy washdown area required stainless fasteners. For many years the specifications were mandated from the USDA headquarters in Washington DC. The material of choice they specified 316 stainless. Once a set of prints was approved at the national level it applied all of that type of machinery across the country.
In the 1990's that responsibility was passed down to the local inspector plant level making things much more difficult. Each inspector could mandate whatever fastener, fit, finish or any other specification they thought best for the application in the plants they inspected. That meant rather than making 1 standard machine we could possibly be required to make 45 different versions depending on the USDA inspector in charge.
Standard Permatex Anti-Seize was used in nonfood contact areas and food grade Anti-Seize was used in food contact areas. However, even the term "food contact area" got blurred over the years. Some inspectors considered the area to be within 1 foot of the actual product while others considered it to be up to 3 feet.
The standard anti-seize always worked far better than the food grade. Unfortunately, it was messy by comparison, so the machine had the be fully sanitized after removing or replacing any fasteners that required its use.
The use of anti-seize became so ingrained I use it on almost everything (that doesn't need Loctite) that will be exposed to weather or washdown. So far, it's been well worth the effort. Sometimes it's messy, but 5 years later when it comes to disassembling it makes things much easier.
