There are direct contact and indirect contact standards for food grade air within the food processing & food packaging industry.
The commonly referenced standards are as follows: Compressed air that comes into direct contact with food or beverage products should meet or exceed the ISO 8573-1:2010 Compressed Air Purity Class 2 pressure dew point ≤-40 °C.
Compressed air that comes in to indirect contact with food or beverage products should meet or exceed the ISO 8573-1:2010 Compressed Air Purity Class 4 pressure dew point ≤+3 °C