Plastic food packaging plays a crucial role in preserving product freshness, ensuring quality during transportation, extending shelf life, and complying with Food and Drug Administration (FDA) regulations. When plastics come into contact with food products, they must adhere to strict FDA guidelines, utilizing materials that are certified as safe for use in food packaging. This ensures consumer safety and protects businesses from inadvertently violating food safety laws.
To guarantee food safety, it’s crucial to choose the right materials. Design teams in the food and beverage industry must understand which plastic materials are food-safe to ensure that their products remain safe for consumers. Here’s a comprehensive overview of five FDA-approved plastics commonly used in food contact applications.
Acrylonitrile Butadiene Styrene (ABS): Is It Food Safe?
ABS plastic is an amorphous polymer created by combining acrylonitrile, butadiene, and styrene. ABS is considered a food-grade plastic, making it suitable for use in various food processing tools and applications, such as food processors and refrigerator linings. Its excellent resistance to strain and abrasion, maintained impact resistance at low temperatures, and insulating properties make ABS ideal for food transportation applications. This food-safe plastic is highly flexible and can be easily welded into complex shapes, enhancing its versatility in manufacturing.
ABS plastic: A versatile material for food processing tools due to its strength and flexibility.
While ABS parts are aesthetically pleasing and perform well in applications that don’t involve extreme temperatures, they are susceptible to stress cracking due to poor weathering and solvent resistance.
High-Density Polyethylene (HDPE): A Staple in Food Packaging
HDPE is a thermoplastic widely used in the production of milk jugs, plastic water bottles, cutting boards, cereal box liners, grocery bags, and other types of plastic food packaging. HDPE’s high tensile strength, impact resistance, melting points, and strength-to-density ratio make it an excellent choice for food and beverage packaging. Furthermore, HDPE is a nonporous polymer, enabling the creation of durable, easy-to-clean parts that require minimal maintenance.
Although HDPE provides resistance to mildew, mold, and insects, its weathering resistance is limited compared to other materials. It is also not resistant to oxidizing acids, highly flammable, prone to stress cracking, and non-biodegradable. Additionally, bonding HDPE with other food-grade plastics can be challenging, potentially limiting design and engineering options.
Despite these limitations, HDPE remains a strong contender for creating FDA-approved plastic food containers. Its high heat resistance makes it dishwasher safe, a desirable feature for food packaging. HDPE is also non-leaching, meaning it can be effectively disinfected without leaving harmful residues. Its resistance to most chemical solvents further prevents potentially harmful chemicals from interacting with food and beverages.
Polyetheretherketone (PEEK): High-Performance Plastic for Food Handling
PEEK is a lightweight, strong, and semi-crystalline thermoplastic. Its high melting point and low coefficient of thermal expansion contribute to its excellent dimensional stability. PEEK food handling products can withstand microwave use, dishwasher cycles, and high temperatures during cooking.
PEEK is safe for direct contact with sensitive foods like raw lettuce or fresh dairy products, even during production. Consequently, PEEK food handling components are used in both food packaging and food production. Common products made from PEEK resin include blenders, kneaders, mixing paddles and scrapers, and valves and nozzles on coffee machines.
PEEK excels over other food-safe plastics in terms of design flexibility. It can be manufactured with added colorants for increased visibility, which enhances process safety by making broken or damaged PEEK parts easily detectable during production. This helps prevent potential food and beverage contamination.
Acrylic (PMMA): Transparency for Quality Control
PMMA is a transparent plastic known for its strength and stiffness, providing exceptional optical clarity. This transparency allows for easy analysis and monitoring of food product quality throughout transportation using advanced vision systems or visual inspections.
PMMA is often used for storing milk and other dairy products, oils, and animal feed. It is also used to manufacture mixing bowls, where its transparency facilitates mixing and cooking processes. PMMA is BPA-free and non-toxic in its solid form, and its biocompatibility makes it suitable for use in dentures and cavity fillings.
However, PMMA has limitations, including poor impact resistance, limited heat resistance, weakness against organic solvents, and susceptibility to cracking under pressure due to poor wear and abrasion defense. It’s crucial to consider these drawbacks when deciding whether to use PMMA for food and beverage packaging.
Polypropylene (PP): Versatile and Cost-Effective
PP is a semi-crystalline thermoplastic produced through the polymerization of propene. Lightweight, moldable, and strong, PP is an excellent FDA food-grade plastic. It offers a high melting point, making it safe for dishwasher and microwave use, low water absorption, and excellent chemical resistance.
Polypropylene can be translucent or opaque and can be matched to any color, providing design teams with diverse aesthetic options. The use of colorful PP food components can also enhance process safety and facilitate adherence to food safety best practices.
Despite its high melting point, polypropylene is flammable and prone to thermal expansion, which limits its high-temperature applications. PP is also susceptible to UV degradation, oxidation, and damage from chlorinated solvents. Its poor bonding properties can restrict manufacturing opportunities, requiring careful consideration during the design and material selection process.
Choosing the Right Food-Grade Plastic
When designing parts or products for food and beverage handling, it is essential to carefully evaluate the various plastic materials available. Some plastics excel in packaging due to their strength, chemical resistance, and durability, while others are better suited for direct contact with food because of their safety, resistance to high temperatures, and formability into intricate shapes. The decision also involves weighing the advantages of transparent plastics for visibility against those of brightly colored plastics for improved safety.
An experienced manufacturing partner can guide you through these considerations, helping you select the FDA-approved plastics best suited to your specific needs. By choosing the right food-safe plastic, you can manufacture aesthetically pleasing, high-performance parts and projects with confidence.
