By embedding a microscopic change in a pattern of pixels—called an invisible bar code—on the label, software can instantly identify the package so it can be sorted and recycled correctly.

Plastic recycling code no. 5 – PP Polypropylene (PP) is the “microwave-safe” type of plastic such as Tupperwares, kitchenwares, prescription bottles and takeout containers.

For plastic recycling in particular, the plastic identification code (three chasing arrows with the number 1 to 7) informs consumers and the sorting facility what kind of plastic it is made out of ...

Two manufacturers of plastic venting systems are pushing for a national fuel gas code in the United States that requires Underwriters Laboratories Inc. certification for use in some natural gas ...

Reusing plastic bottles with codes #1 and #2 is probably fine to do on occasion, provided you take certain precautions.

Plastic cups made of foam (plastic code 6) or polypropylene (plastic code 5) could be used,” he explained.

Electronic labels made from plastic semiconductors can now pick up and respond to radio signals at a frequency suitable for use on products.

What the secret code on your plastic packaging means It’s a confusing code that doesn’t make much sense to the untrained eye, but the consequences of not knowing what it means could be lethal.