1 Plastics with recycling symbol 2, 4, and 5 are generally considered OK to use. 2  Plastics with recycling symbol 7 are OK to use as long as they also say PLA or have a leaf symbol on them. 3  The recycling symbol number is the code that shows what type of plastic was used to make the product. Plastics with recycling symbol 2, 4, and 5 are generally considered OK to use. 2  Plastics with recycling symbol 7 are OK to use as long as they also say PLA or have a leaf symbol on them. 3  The recycling symbol number is the code that shows what type of plastic was used to make the product.