| Polypropylene (PP) | 5 | Hot meals, soups, sauces, reusable meal-prep containers | Approximately 100–120°C (212–248°F), depending on design and grade | Generally suitable when specifically labeled microwave-safe; vent the lid | Generally suitable; check for brittleness and the manufacturer's temperature rating | Good heat resistance, low density, good fatigue resistance, and strong resistance to many chemicals | Can warp if exposed to temperatures above its rating; not every PP container is microwave-safe | The most versatile option for hot takeout and reheating |
| High-Density Polyethylene (HDPE) | 2 | Cold food tubs, dairy containers, bottles, and food storage containers | Approximately 80–100°C (176–212°F), depending on grade and wall thickness | Usually not preferred for microwave heating unless expressly labeled microwave-safe | Generally suitable for cold and frozen storage; allow room for food expansion | Tough, lightweight, moisture-resistant, and resistant to many acids and alkalis | Lower heat resistance than PP; may deform when filled with very hot food | Cold takeout, chilled foods, and freezer storage |
| Polyethylene Terephthalate (PET) | 1 | Cold salads, fruit, desserts, drinks, and clear display containers | Typically below approximately 60–70°C (140–158°F) for standard containers | Not recommended unless the specific container is clearly labeled for microwave use | Generally suitable for chilled or frozen foods when designed for that purpose | Excellent clarity, good stiffness, and effective moisture and gas barrier properties | Can deform with hot food; heat may increase the risk of container distortion and migration concerns | Cold food, chilled beverages, and presentation-focused packaging |
| Polystyrene (PS) | 6 | Cold foods, bakery items, disposable trays, and rigid food service containers | Approximately 60–75°C (140–167°F), depending on form and grade | Not recommended for microwave heating | Suitable for some cold applications, but performance varies by container design | Low cost, lightweight, and easy to form; rigid PS provides good presentation | Poor heat resistance; brittle at low temperatures; recycling availability is limited in many areas | Short-term cold-food service where reheating is not required |
| Expanded Polystyrene (EPS) | 6 | Insulated cups, clamshells, and containers for short-term hot or cold food service | Generally below approximately 80°C (176°F); exact limits vary significantly | Not suitable for microwave heating | Can be used for cold foods, but structural performance varies | Very lightweight and provides thermal insulation | Low structural strength, poor heat tolerance, high volume in waste streams, and limited recycling access | Insulated short-distance service when reheating is unnecessary and local rules permit its use |
| Polylactic Acid (PLA) | 7 or varies | Cold salads, fruit, desserts, and cold beverages in designated compostable packaging systems | Typically below approximately 45–55°C (113–131°F) unless heat-resistant modified PLA is used | Not suitable for microwave heating unless specifically labeled for it | May be suitable for cold or frozen food, subject to the product specification | Can be made from renewable feedstocks and may be compostable in suitable industrial facilities | Softens at relatively low temperatures; industrial composting is required for many PLA products | Cold-food service where compatible commercial composting infrastructure exists |
| Crystallized PET (CPET) | 1 | Ovenable ready meals, frozen meals, and heat-and-eat food trays | Approximately 180–220°C (356–428°F) for products specifically designed and labeled for oven use | May be suitable when the specific product is labeled microwave-safe | Generally suitable for frozen-food applications when specified by the manufacturer | High heat resistance, dimensional stability, and suitability for certain ovenable applications | More specialized and usually less clear than standard PET; temperature limits are product-specific | Heat-and-eat meals requiring validated oven or microwave performance |