Materials of construction used for equipment must be completely compatible with the food product, environment, cleaning chemicals and disinfectants and the methods of cleaning and disinfections.
Carbon steel cannot be used in the food contact are due to its corrosion sensitivity especially by salt and chlorine-containing bleach.
The preferred material for food contact surfaces is stainless steel because it is strong, easily, cleaned and resistant to rust and many cleaning/sanitizing compounds. Stainless steel AISI SS 304 (L) can be used for the construction of food processing equipment and food processing support system in applications with low chloride level, near neutral pH and at low temperature.
The best known application copper is vessels, traditionally used in many breweries and distilleries. Copper does not relay constitute a food safety problem but it is recommended to avoid direct contact with copper utensils, as they can cause unacceptable organoleptic effects. Moreover, alkaline materials used on copper equipment may cause a discoloration of foods. It is generally undesirable to use copper in food processing equipment, even though it is among the best conductor of heat available.
Monel metal an alloy consisting mainly nickel and copper, is suitable for food processing equipment but is expensive.
Aluminium conducts heat well but subject to corrosive when contacting alkaline materials or fruit acids.
Generally, high quality stainless steels, plastics and other materials approved for food contact are used. If care is taken in selecting equipment and contact surface materials taking into account the nature of the food being processed, there is minimal chance of harmful contamination.
Misuse of equipment or use of materials incompatible with the material being processed may result in contamination.
Type of material for processing equipment
