Dry-Packs 1/2gm Tyvek Silica Gel Packet, Pack of 50 Packets contain silica gel which is a non-toxic and inert moisture absorber Silica gel can absorb 40-percent of its weight in water vapor Tyvek packaging meets FDA specifications for use in dry food packaging Fight mold, mildew, corrosion and rust with silica gel Provides superior absorption-remains dry at maximum saturation