TOC Vials, Sievers Certified | VWR. Sievers Certified (<10 ppb) TOC Vials are designed for use in critical pharmaceutical applications such as USP and EP water testing as well as municipal water testing. Certification to below 10 ppb gives you confidence in the quality of TOC measurements.Vials are available in all capacities, materials like plastic vials or glass vials, and in a variety of colors to meet any collection, storage, or analysis need.