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
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