Plastics By Number

Plastic labeling is given a number with three arrows chasing each other around to create a triangle. Sometimes you will also see letters beside the symbol to identify the type of plastic (e.g., PET, LDPE). Numbers 1-7 are recyclable to various degrees, depending on your town or city’s recycling program. The safest plastics to reuse are #2, #4 and #5 (sing it…
2, 4, 5 keep yourself alive)! That means, #1, #3, #6 and #7 are best purchased in moderation and do recycle after ONE use.

http://www.davidsuzuki.org/files/NC/newsletter/plasticsbynumber.pdf

Print the page on the link above for a quick reference for which plastics are ok to reuse, recycle and avoid.