What do the numbers in the recycling logo mean?

Question

For example, a bottle water could be 2 or something. Other materials that have those numbers are shampoo bottles, Starbucks cup, etc. Does anyone know what the numbers it stand for?

Answer 1

Carlo already gave a great, and very complete, answer.  On some products, you can see that there are also some capital letters under the icon.  These letters correspond to the type of plastic just like the number does.  For example, on a foam cup or lid you might see the #6 inside the triangle, and underneath it would be "PS."  6's are PolyStyrene.  On another product you might see HDPE for High Density PolyEthelyne.  If you are trying to actually memorize what the numbers mean, the letters can be helpful reminders.

It can be really interesting to see the different products made from recycled plastics.  Most people aren't aware that #6 polystyrene foam IS recyclable.  It is just hard to find a place that will accept it.  PS can be recycled into polar fleece.  It used to be used for making the plastic VHS tape housings too.  There are lots of other post-recycle products, but I always thought those were the most interesting.

Answer 2

They stand for how biodegrade able they are. Water bottles don't take as long as other things to biodegrade so they have a 2 instead of a 6.

Answer 3

1 Poly(ethylene terephthalate):  Soda bottles, water bottles, vinegar bottles, medicine containers, backing for photography film.

2 High-density Polyethylene:  Containers for:  laundry/dish detergent, fabric softeners, bleach, milk, shampoo, conditioner, motor oil. Newer bullet proof vests, various toys.

3 Poly(vinyl cloride):  Pipes, shower curtains, meat wraps, cooking oil bottles, baby bottle nipples, shrink wrap, clear medical tubing, vinyl dashboards and seat covers, coffee containers.

4 Low-density Polyethylene:  Wrapping films, grocery bags, sandwich bags.

5 Polypropylene:  Tupperware®, syrup bottles, yogurt tubs, diapers, outdoor carpet.

6 Polystyrene:  Coffee cups, disposable cutlery and cups (clear and colored), bakery shells, meat trays, "cheap" hubcaps, packing peanuts, styrofoam insulation.

7 Other. Products labeled as "other" are made of any combination of 1-6 or another, less commonly used plastic.

Answer 4

Those designate different types of plastic.  Recycling works best if you've got a whole bunch that's all "6 Polystyerene" and nothing else to contaminate it.  Then you can soak off the labels, melt it into a big vat of polystyrene and make something else.

Not all kinds of plastic are practical to recycle right now, so your recycler only takes some kinds.  

Recycling plastic saves petroleum, because plastics are made of petroleum.   The Shah of Iran once said "I can't believe you burn oil for fuel.  It's too valuable for making plastics."

It's possible to make plastics out of vegetables like corn.