The Food Safety Modernization Act (FSMA) requires that all materials used in the manufacture of food-contact surfaces and utensils must coincide with compulsory food safety standards.
Thorough research is needed when deciding what type of food-grade metal you’ll require for your particular manufacturing process and selecting the best food-grade metal requires a comprehensive understanding of its use. Awareness of what is involved in your particular food production, such as certain compounds used, temperatures and methods, will enable you to choose the right equipment for your particular industry.
Conditions of food-safety metals are that they must…
- Be durable and non-absorbent.
- Be resilient to scratching, scoring, and chipping.
- Be resistant to corrosion.
- Be impermeable to harmful substances.
- Have a smooth, easy to clean surface.
- Be adequate enough to withstand repetitive cleaning.
Using the wrong kind of metal for a particular food manufacturing process could have destructive results, leading to food contamination, sickness and at worst death. There are limitations on what metals can be used and how they can be used, so it’s vital to choose the right ‘food-safe’ metal for your specific trade. Stainless steel is generally one of the safest and most prevalent options.
Stainless Steel grades:
There are three main types of stainless steel used globally. Food-safe 304 steel is the most commonly used for stainless steel benches, stainless steel sinks and delivers standard structure and strength, and with its renowned anti-corrosion resistance, its suitable for most food products. Grade 316 is less commonly used but is more expensive and infinitely superior in its resistance to chlorides and acids and is used in high-end food machinery production. The 430 steel is a cheaper option, with less nickel content, making it less resistant to rusting, but maintaining its strength against stress corrosion. It is adequately substantial for splashbacks and specific catering apparatus.
It’s therefore imperative to acknowledge what elements and processes you’ll be using in your particular industry before deciding on what safe-food metal will be best suited to your requirements.
- Austenitic stainless steel is known for its resistance to corrosion. It contains high levels of chromium and nickel (important elements for heat resistance and enhanced surface quality) with low levels of carbon (rendering it flexible and malleable). It is non-magnetic and is recognized for its robust composition and resistance to deterioration.
- Ferritic stainless steel contains chromium. The strength of this particular alloy helps with temperature oxidation resistance and helps prevent seeping in pots and pans, and owing to a high concentration of iron, it is both strong and magnetic, making it resistant to corrosion and stress.
- Martensitic stainless steels are hardened by heat treatment and can achieve high levels of endurance, essential in accomplishing a good cutting edge, combined with excellent corrosion resistance. Its highly advocated for use in the manufacturing of kitchen knives and cutting tools. The high carbon grades are excellent for durability and wear, and the presence of iron makes it magnetic, though not as much as in the ferritic or duplex steels.
- Duplex stainless steel consists of ferritic and austenitic grains, making it twice as strong and flexible, implying that the thickness can be considerably reduced, thus resulting in lower cost, yet still maintaining its’ magnetic domain, strength, erosion and abrasion resistance.
Stainless steel Pros:
- Durable and strong.
- High-energy concentration, and low thermal development.
- Resistance to stress and corrosion.
- Manufactured to handle high temperatures.
- Easy to maintain.
Whilst other metals such as aluminium, copper and zinc are used in the food industry, and modified during the manufacturing process to be considered safe, by far the most widespread and reliable food-safe metal within the food industry is stainless steel.