Environmental technology verification (ETV) is an independent (third party) assessment of the performance of a technology or a product for a specified application, under defined conditions and Quality Assurance (QA). This verification was a joint verification between NOWATECH Water Monitoring ETV Center (NOWATECH WMC), operated by DHI, and the Advanced Monitoring Systems Center (AMS) operated by Battelle under a cooperative agreement with the US Environmental Protection Agency (US EPA). The plan used during testing and verification consisted of a joint verification protocol and test plan. The compliance with both schemes requirements was ensured through a process document. This report is a summary of the verification done and the performance data obtained. The product verified was the Sorbisense GWS40 passive sampling system (106-012-11) with samplers (cartridges) for analysis of volatile organic compounds (VOCs) (no. 043-091-12, 043-101-12, 043-102-12). Analysis of the samplers was performed by ALcontrol under ISO 17025 accreditation. The passive samplers and the subsequent analysis of the cartridges constitute the product.