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.

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

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

Ever wonder what those small numbers on the bottom of your plastic bottles and takeout containers mean? They're called Resin Identification Codes. Follow BI Video: On Twitter More from Science ...

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 ...

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.

Plastic code Recycling symbol can’t appear on non-recyclable items, California bill says California wants to clear up confusion about which plastics can be recycled.