<<Disclaimer: Verify this information before applying it to your situation.>>

I just spoke with Celestial Seasonings at their consumer
info. line   800 351-8175

I was told that their bags are heat-sealed.  The bags
themselves are GF.  However, not all of their teas and
tea blends are GF - some have barley, etc.  so check
ingredients on the box before buying.

Their equipment is thoroughly cleaned, with no residue,
between runs of different types of teas/tea blends, due
to their Kosher certification.

Vicki