Is it safe to microwave plastic containers or wraps? In today’s blog, we’ll go over the most common types of plastic used in food packaging and explain which ones are truly microwave safe.
What plastic can be microwaved？
Polypropylene (PP), also known as #5 plastic, is the only microwave-safe plastic. It is widely used in microwave-safe PP bowls (lunch boxes), food storage containers, and takeout boxes.
Microwave safe plastic symbol
At the bottom of the container, you will usually find the marking “PP5” or a “Microwave Safe” label/icon.
Is microwave-safe plastic really safe？
Polypropylene (PP 5) is internationally recognized as a microwave-safe material and is the most common plastic used for making microwavable food containers. In general, regular PP starts to soften at around 110–120 ℃, while modified PP can withstand up to about 140 ℃.
For safe use of microwave oven safe plastic containers:
- Be careful with foods like pizza or fried items. These can create localized overheating in the microwave, which may exceed PP’s heat resistance, causing the container to deform or release harmful substances.
- Always leave the lid slightly open when heating to prevent pressure build-up. A tightly sealed lid may warp or even burst. If the lid has a steam vent, keep it open.
- Avoid reusing disposable PP containers too many times, as repeated use accelerates plastic aging.
- Containers marked PP5 Microwave Safe may also be labeled as Dishwasher Safe, but you’ll rarely see Oven Safe. Do not place PP containers in an oven—they will melt.
Microwave-safe plastic wraps
For microwave heating, choose plastic wraps made from PVDC or PMP, which are heat-resistant and not easily affected by oil.
Tips to keep in mind:
- Avoid wrapping foods that are very oily before microwaving, as the wrap may melt.
- Do not place these wraps in a conventional oven, since they cannot withstand high baking temperatures.
PE plastic wrap, on the other hand, is less heat-resistant and sensitive to oil. It is generally not recommended for microwave heating. While it can tolerate about 110–120 ℃ and may be used on low microwave settings, it should not be used with oily or sugary foods.
Non-microwave safe plastics
PET (#1 plastic): Commonly used in disposable plastic bottles, such as bottled water and soft drinks. It has poor heat resistance and may release plasticizers at high temperatures, making it unsuitable for microwave heating.
LDPE (#4 plastic): Low-density polyethylene, often found in plastic wraps and food storage bags. While safe for holding food, it has weak heat resistance.
PS (#6 plastic): Polystyrene, commonly used in disposable takeout boxes and food containers. It starts to deform at around 75 ℃ and softens significantly at 100 ℃. High heat may also release styrene, a potential carcinogen.
PC and others (#7 plastic): Polycarbonate or other plastics (e.g. some reusable bottles) can be used for food contact, but may release harmful substances when exposed to high heat.
In addition, HDPE ( #2 plastic) and PVC (#3 plastic) are generally not used for microwave-safe types of packaging materials for food.
Other food packaging that shouldn’t be microwaved
Paper containers: Usually coated with PE film for water and oil resistance. However, the coating can soften and melt above 90 ℃, potentially contaminating food and posing safety risks.
Aluminum foil containers: Heat-resistant and oven-safe, but not suitable for microwaves. Foil reflects microwaves and may cause sparks.
Tip: When in doubt, transfer food to a ceramic or glass dish before heating—it’s safer and more reliable.
Before wrapping up
As a leading China sourcing company with over 10 years of experience in food packaging, we are always glad to share our knowledge. If you found this blog helpful or have any questions, feel free to leave a comment.
If you are in the food service industry and need microwave-safe plastic packaging or want to optimize your supply chain, chat with us. We provide cost-effective, tailored packaging solutions, often better than what you’d find locally or on Alibaba.
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