Concerns Related to Storing Lettuce in Plastic Too Long

The best way I have found and it works is to store it in a water sprinkled kitchen towel wrapped around it in the veggie drawer. Last for days. Green a crispy!

I concur with Michawnpita! If what you're talking about is leeching from different plastics then check out this link:
http://www.care2.com/greenliving/safe-plastics-for-lunchboxes.html#

I have heard of no such thing. I do know that you can't store lettuce in plastic that long anyway, or it gets yucky! I would think that anything that would grow would be long after a good eatable lettuce survived anyway!