Understanding Food-Grade Plastic Trays
To identify a food-grade plastic tray, you need to look for specific, standardized markings, understand the resin codes, and verify any certifications from the manufacturer. Food-grade plastics are those deemed safe for contact with food by regulatory bodies like the US Food and Drug Administration (FDA) or the European Food Safety Authority (EFSA), meaning they do not leach harmful chemicals into food under their intended conditions of use. The most direct way is to check for the Resin Identification Code (RIC), the number inside the chasing arrows symbol, but this is just the starting point. Not all plastics with these codes are automatically food-safe; their safety depends on the specific formulation and intended use.
The Critical Role of Resin Identification Codes (RIC)
The number inside the triangular recycling symbol is your first clue. Developed by the plastics industry, this system helps with sorting for recycling, but it also indicates the general type of plastic. For food contact, some codes are more common and generally considered safer than others. Here’s a detailed breakdown of the codes you’re likely to find on trays and what they mean for food safety.
| RIC Code | Plastic Type | Common Uses in Food Trays | Food-Grade Safety Notes |
|---|---|---|---|
| 1 | PET or PETE (Polyethylene Terephthalate) | Single-use salad containers, drink bottles. | Generally considered safe for single use. Can leach antimony with heat or prolonged use. |
| 2 | HDPE (High-Density Polyethylene) | Yogurt tubs, milk jugs, sturdy trays. | One of the safest and most stable choices. Resistant to chemicals and moisture. |
| 4 | LDPE (Low-Density Polyethylene) | Flexible lids, bread bags, squeeze bottles. | Safe for food contact, known for its flexibility and toughness. |
| 5 | PP (Polypropylene) | Microwave-safe meal trays, deli containers, syrup bottles. | Excellent heat resistance (up to ~160°C/320°F), making it ideal for microwaving and hot foods. A top choice for food-grade trays. |
| 6 | PS (Polystyrene) | Foam meat trays, rigid disposable cutlery, clear clamshells. | Can leach styrene, a possible human carcinogen, especially when heated or in contact with oily foods. Avoid using foam PS trays for hot or fatty foods. |
| 7 | OTHER (Includes Polycarbonate, PLA, etc.) | Multi-layer packaging, reusable water bottles. | This is a catch-all category. Safety varies wildly. PLA (polylactic acid) is a compostable bioplastic and is food-safe. Polycarbonate (often containing BPA) should be avoided for food. |
It’s crucial to remember that the RIC code alone doesn’t guarantee safety. A #5 PP tray is a good bet, but a #7 tray could be made from BPA-containing polycarbonate or from perfectly safe PLA. The code tells you the base resin, not the additives. This is why the next step is so important.
Looking Beyond the Code: The “Food-Safe” or “FDA-Compliant” Label
Manufacturers who produce items intended for food contact will often explicitly label them. Look for phrases like:
- “Food-Grade”
- “FDA Compliant” or “Meets FDA Standards”
- “Safe for Food Contact”
- For European products, look for the glass-and-fork symbol
These labels indicate that the manufacturer has ensured the final product, including all colorants, plasticizers, and stabilizers, complies with relevant safety regulations. For instance, a plastic might be FDA-compliant for holding fresh vegetables but not for holding acidic foods or alcoholic beverages, as these can cause more chemical leaching. The manufacturer’s specifications should outline the intended use. If you are buying in bulk for a business, always request a Certificate of Compliance (CoC) from the supplier, which documents the material’s safety.
Physical and Sensory Clues
While not a substitute for checking codes and labels, your senses can provide warnings. Non-food-grade plastics, often intended for industrial use, may have a strong, pungent chemical smell. A food-grade tray should have little to no odor. If you open a package and are hit with a powerful “plastic” smell, it’s best to avoid using it for food. Similarly, examine the tray’s clarity and rigidity. Poorly made, non-compliant plastics might appear cloudy, have uneven coloring, or feel brittle. A high-quality Disposable Takeaway Box designed for food will typically be robust, with a consistent texture and color, and free of any strong odors.
The Impact of Heat and Usage
Food-grade status is context-dependent. A tray safe for storing dry pasta at room temperature may not be safe for microwaving leftovers or storing a hot, oily curry. Heat significantly increases the rate at which chemicals can migrate from the plastic into the food. This is why you see specific “microwave-safe” labels. This designation means the plastic has been tested to ensure it won’t warp, melt, or leach unacceptable levels of chemicals when heated. As a rule of thumb, only plastics labeled #5 (PP) are reliably microwave-safe. Never microwave food in trays marked #1 (PET), #3 (PVC), #6 (PS), or #7 (unless specifically labeled as microwave-safe, like some PLA products).
Reusability and Degradation
Another angle to consider is whether the tray is designed for single use or multiple uses. Thin, single-use trays, especially those made from #1 PET or #6 PS, can develop tiny scratches and cracks with washing. These imperfections can harbor bacteria and increase the potential for chemical leaching in subsequent uses. If you plan to reuse a plastic tray, it’s better to choose a thicker, more durable tray made from #2 HDPE or #5 PP, which are more resistant to wear and tear. Furthermore, exposure to sunlight and extreme temperatures over time can cause plastics to degrade, making them brittle and potentially compromising their food-safe properties.
Regulatory Frameworks and Certifications
Globally, different regions have their own strict regulations. In the United States, the FDA regulates food-contact substances under Title 21 of the Code of Federal Regulations. In the European Union, regulation (EC) No 1935/2004 sets the framework, requiring that materials do not transfer their constituents to food in quantities that could endanger human health. For a consumer, looking for a mark from an independent testing laboratory, such as NSF International, can provide an extra layer of assurance that the product has been rigorously tested against these standards.