Most Plastic Containers Are Not Recyclable


The SPI Resin Identification Symbol System

Plastic labelling can be misleading, because you need to know what the numbers mean to know whether an item is safe to re-use as your lunchbox. Most aren’t.

What do the plastic recycling symbol mean?

The bottom line: plastic containers from groups 2, 4, and 5 below can be re-used, but avoid the others.

1: PET or PETE
This is commonly used in drink bottles. It is recyclable (mostly for textiles and carpets) but it is meant to be used once and should not be reused at home, not because of the toxins, but because it breaks down and it becomes a breeding ground for bacteria.
PET or PETE: Polyethylene Terephthalate
Used in milk bottles, yogurt tubs, cereal box liners. This is recyclable (pipes and plastic furniture) and has low risk of toxin leeching.
Reusable and recyclable
HDPE: High Density Polyethylene
3: V or PVC
This is widely used but not in the food industry. Everything that is bad about plastic - it can even releases poison in the air. It used in some cling films and children toys.
Toxic and non-recyclable
V or PVC: polyvinyl Chloride
#4: LDPE
Strong and flexible, used in cabling, medical industry and as shopping bags, but also for food packaging such as squeezable bottles like honey or baby bottles.
Recyclable and reusable
LDPE: Low density Polyethylene
#5: PP
Another good one, tupperware and baby bottles are made from this.
Reusable and recyclable
PP: Polypropylene
#6: PS
Widely used (egg cartons, disposable cups) but it is know to leach toxins into foods. Styrofoam belongs to this group. Another bad one.
Not easily recyclable; better not to reuse
PS: Polystyrene
#7: Other
Anything else - this group includes both harmless and compostable plastics made from vegetables, and others such as policarbonate who can leach potential hormone disruptors.
Not recyclable and not reusable (unless the precise type is known to be harmless).
Other: anything not covered above

Who invented the plastic codes?

The symbols (officially called the SPI Resin Identification Symbol System) were devised in 1988 by a trade body, the SPI (Society of Plastic Industry). Some people feel they should be changed to something that gives a visual clue as to whether the plastic is recyclable or not. If you’d like to add your voice, here is the feedback form on the SPI website - you never know.

More info

This info is readily available on WikiPedia and via Google search.