the general consensus and official instructions from cup noodle manufacturers were to avoid microwaving the noodles in the Styrofoam cup. The reason for this warning is that Styrofoam (polystyrene) is not designed to withstand the high heat generated by a microwave, and there is a risk of the cup melting, releasing harmful chemicals, or causing a fire.
Although some older cup noodle packaging might have indicated it was safe to microwave the cup, it's crucial to follow the most recent instructions and warnings provided by the manufacturer. Over time, safety guidelines and product specifications can change based on new information, research, or regulations.
The current instructions provided by Nissin and Maruchan advising against microwaving the Styrofoam cup should be followed to ensure your safety and prevent any potential hazards. If you still prefer to use a microwave, it's recommended to transfer the contents of the cup to a microwave-safe container before heating. Always read and adhere to the instructions on the packaging to enjoy your cup noodles safely.