I did the same with mine – prepared for the worst, but pleasantly surprised:

WHAT IS THE FILTER PAPER MADE OF THAT YOU USE IN YOUR TEA BAGS?

The filter paper used for Yamamotoyama tea bags is made from 100% cellulose fibers (wood). Test results conclude that chlorine dioxide is not present in our tea bag filter paper. The filter paper is not coated with the compound epichlorohydrin, and does not contain any free epichlorohydrin. Yamamotoyama tea bag filter paper is machine folded and pressed, therefore no glue is needed or used. Our teabags are completely compostable.