From this page you can access the MSDS (Material Safety Data Sheet) for the product:
http://www.behr.com/consumer/products/wood-stains-finishes-cleaners-and-strippers/behr-semi-transparent-waterproofing-wood-stain

Staining the outside only will only protect the outside. I keep my raised beds simple - 2" x 10" untreated pine - and they last about five years, after which I simply replace the boards as necessary.

Or use western red cedar or redwood and they'll last for about 25 years.

That's fine if one can afford red cedar or redwood ... and expects to last 25 years oneself :-)