Whirl-Pak Thio Bag - sterilised Water Sampling Bags containg Sodium Thiosulfate, 100mL. Specially designed for sampling and neutralising chlorinated water in preparation for Heterotrophic Plate Counts, the Whirl-Pak® Thio-Bag® is economical and convenient to use. This single use, sterilized, lightweight, unbreakable container is always ready for immediate use. The write-on strip will accept virtually any writing instrument and minimizes ink smearing on the surface. These markings help the operator collect the correct amount of water as required by the testing procedure (fill lines are approximate). Comes in 100/Box.