A 12x14 restroom (no shower, nor tub) is being built in our workplace. Can tile be glued directly to the green board walls since there is no shower or tub. If so will the greenboard have to be sealed before tiling or can the tile be installed directly on the raw green board? Also what would the best adhesive be for ceramic tile to greenboard?

Thanks

P.S. I am calling "Continental Building Products Mold Defense Drywall Panel " Greenboard because that is what the store clerk called it .