Which plastics are safe as plant containers to grow vegetables? Which ones should not be used?

Plastic containers that you may consider to grow vegetables will need to be from plastics Nos. 1, 2, 4 and 5.

Mnemonic: 1-5 (skipping #3).

Pay attention to the recycle numbers on the bottom of the plastic container – avoid plastics numbered 3, 6 and 7.

Plastic containers made of No. 3 have PVC in them which could be carcinogenic.

Styrofoam cups are made of plastic No. 6 which could be carcinogenic.

No. 7 containers contain bisphenol A.

Plastic items are marked with a resin identification coding system (the number surrounded by arrows), which stand for:

1 - polyethyelene terephthalate (PETE)
2 - high-density polyethylene (HDPE)
3 - vinyl, polyvinyl chloride (PVC)
4 - low-density polyethylene (LDPE)
5 - polypropylene (PP)
6 - polystyrene (PS)
7 - other (includes polycarbonate, acrylic, polylactic acid, fiberglass)

When you need to use plastic, these are the safer choices to use with food: 1, 2, 4 and 5.

You can make your own potting mix:

- 30% peat moss or coco coir
- 30% perlite or vermiculite
- 30% compost or soil

References:

Kitchen Plastic: Easy Greening | Care2 Healthy Living - http://goo.gl/zwb8S

Safe Containers for Growing Food | - http://goo.gl/G2CVy

Food Grade Plastic Containers For Brining http://bit.ly/NnZQeh

Which Plastics Are Safe For Gardening? - Epic Gardening http://bit.ly/12qQcEi