in addition to my answer just posted, here are a few links that you may find useful:
http://venusrecommends.com/plastic-planting-pots-compost-makers-raised-beds/
http://venusrecommends.com/safe-plastic-how-to-know/
http://venusrecommends.com/5-pp-plastic-the-difference-is-essential/

Gratefully,
Venus

Thanks for your great question! and for caring for your safety.
I truly appreciate you.
Yes, some terra cotta pots have lead, PCBs, dioxins and other toxins;
to make sure you pick the safest pots for your vegetables,
select either pots made of plastic number 5
(on the bottom of the pot in a triangle it is supposed to be
written the number plastic it is made of; it is to say 5 and
the letters PP – this is safe); make sure the plastic is NOT recycled, but new.
You can also get wood containers made of non treated wood
(treated wood has toxins on it – this is what makes it treated) or
you can even make some planting containers yourself very inexpensively by getting
plain wood from Home Depot or LaValley; if you decide to go with pots made of clay,
make sure they are NOT made in China, but in Italy instead; also,
make sure they do NOT have a glossy glaze because it is usually toxic;
and make sure they are just plain brick brown in color instead of having
different paint on them because the paint will be toxic.
These are your safest and best options.
Let me know if I answered your questions and
if you have more questions.
Happy planting!
Infinite love and gratitude to you,
Venus