| Polypropylene (PP) | Meal-prep boxes, soup containers, deli tubs, and microwaveable food trays. | Good resistance to heat and freezing. Microwave use is appropriate only when the container is specifically labeled microwave-safe. | Generally stable for food contact when manufactured for that purpose. It has a relatively high melting point compared with many other common food-packaging plastics. | Containers can deform if exposed to direct flame, ovens, or temperatures beyond the stated specification. Repeated heating may shorten service life. | Choose PP for hot or reheatable foods when the package includes clear microwave and temperature instructions. | Plastic code 5 |
| High-Density Polyethylene (HDPE) | Cold food tubs, milk-style containers, produce packaging, and liquid food containers. | Performs well in refrigerated and frozen storage. It is not generally the first choice for microwave heating unless specifically labeled for that use. | Good moisture resistance and chemical resistance. Food-contact grades are widely used for cold and ambient foods. | Can soften or deform with high heat. It is less suitable for hot filling or reheating than heat-resistant PP unless the manufacturer provides approval. | Use for chilled foods, dry foods, and short-term freezer storage; follow the stated temperature range. | Plastic code 2 |
| Low-Density Polyethylene (LDPE) | Disposable food bags, liners, flexible pouches, and lightweight wraps. | Flexible at low temperatures and suitable for refrigerated or frozen storage. High-temperature use should be avoided unless specifically approved. | Good moisture barrier and flexibility. Food-contact LDPE is commonly used for products that need soft, tear-resistant packaging. | Lower heat resistance and lower stiffness than PP or HDPE. It may stretch or deform when filled with very hot food. | Select LDPE when flexibility and moisture protection matter more than rigidity or hot-food performance. | Plastic code 4 |
| Polyethylene Terephthalate (PET) | Cold beverage cups, clear salad containers, fruit packs, and chilled ready-to-eat foods. | Suitable for refrigerated storage and many cold-food applications. Standard PET should not be heated unless it is designed and labeled for heat exposure. | Clear, lightweight, and provides a good barrier against moisture and gases. Food-contact PET is commonly used for cold packaged foods. | Standard PET may deform with heat. It is not normally suitable for microwave use or hot filling without specific instructions. | Choose PET when product visibility and cold-food protection are priorities. | Plastic code 1 |
| Polystyrene (PS) | Cold-food cups, lightweight trays, bakery packaging, and some disposable takeout containers. | Best suited to cool or room-temperature foods. Avoid hot foods and microwave heating unless the product is expressly labeled for those conditions. | Lightweight and rigid, with useful insulation when made as expanded foam. Food-contact suitability depends on the specific formulation and intended use. | Limited heat resistance; hot, oily, or acidic foods may increase the risk of deformation or unwanted transfer from packaging, particularly when the product is not designed for that food. | Use mainly for short-term cold-food service and follow local restrictions on expanded polystyrene packaging. | Plastic code 6 |
| Aluminum | Roasting trays, takeout pans, foil containers, and oven-ready food packaging. | Handles oven temperatures well when the package is designed for oven use. It must not be used in a microwave unless the appliance and packaging instructions specifically permit it. | Excellent barrier against light, oxygen, moisture, and odors. It is non-combustible under normal food-heating conditions and suitable for many oven applications. | Reactive with strongly acidic or salty foods over extended contact. Sharp edges may cause cuts, and containers can be easily bent or punctured. | Select aluminum for oven cooking, heat retention, and strong barrier protection; keep it away from microwave heating unless explicitly approved. | Metal; recycling practices vary by location |
| Molded Fiber or Bagasse | Takeout boxes, plates, bowls, clamshells, and disposable trays for hot or cold foods. | Often suitable for hot food and short-term reheating, but microwave and oven performance varies by design, coatings, and manufacturer instructions. | Made from plant-based fibers and can provide a rigid alternative to plastic or foam. Food-contact safety depends on the fiber source, additives, coatings, and compliance testing. | May absorb liquids or oils unless coated. Some coatings can affect recyclability or compostability. “Compostable” claims require suitable local facilities and conditions. | Choose products with clear food-contact approval and verified PFAS-free, compostability, or recycling claims when those properties are important. | Fiber-based; no universal resin code |