What plastic is this part in your hand made from? How do you determine what plastic it is? Here are four good places to start: PLASTIC RESIN IDENTIFICATION CODES The plastics identification codes were developed in 1988 by the SPI Society of Plastic Industries. These codes are intended to be recycling codes. #1 is polyethylene terephthalate (PETE, PET), and #2 is high-density polyethylene (HDPE). #3 polyvinyl chloride (PVC), #4 low-density polyethylene (LDPE),