Gas sampling bags are air sampling devices that come in several different types for the purpose of collecting gases to be tested. Users should select the appropriate bag based on the type of gas they will be sampling.
Types of Gas Sampling Bags
The most common types of gas sampling bags include:
- Environmental testing labs collect gas samples as part of field service testing for their clients in Tedlar bags*, classic bags referenced in numerous EPA methods which are used to collect carbon dioxide and also methane, sulfur compounds, sulfur hexafluoride and other volatile organic compounds (VOCs).
- Multi-Layer gasbags with a foil barrier are used mainly for compounds of low molecular weight such as CO, CO2, methane, hydrogen and SF6. These gasbags hold hydrogen sulfides for 48 hours with high sample retention percentages. These protect the samples from light and moisture which can compromise the quality.
- ALTEF modified fluoropolymer film gasbags are used for sampling of aromatics, chlorinated solvents, alcohols and acids, as well as methane, most VOCs, carbon monoxide and carbon dioxide. Unlike Tedlar*, ALTEF does not have trace levels of either DMAC or phenol.
The Importance of Gasbags in Workplace Safety
Under U.S. Environmental Protection Agency (EPA) and Occupational Safety Health Administration (OSHA) regulations, gasbags are required to ensure safety in workplaces that expose workers to gaseous emissions. Gasbags provide expedient access to sampling that can be performed by trained samplers. An environmental testing lab, for example, uses gas chromatography (GC) for testing water and other fluids. The gases workers may be exposed to in GC are argon, helium, carbon dioxide and nitrogen.
Differences in Gas Sampling Bags
Before ordering gas sampling bags, it is important to understand the difference between bag types. Choose gas sampling bags that meet specifications for types of gases to be sampled, bag thickness, tensile strength, operating temperature, vapor permeability and gas permeability.
Questions or comments? For more information, contact Uniphos Envirotronic Inc., a leading manufacturer, supplier and exporter of gas detection and monitoring equipment.
*Tedlar® is a registered trademark of E.I DuPont.