Tedlar Gas Sampling Bags are the Most Common Choice in the Industry
May 7, 2025The selection of a gas sampling bag depends on several factors, like the type of gas, the thickness and strength of the material, its heat resistance, and permeability. Tedlar gas sampling bags are the most common choice for collecting and analyzing gases.
Composition and Characteristics of Tedlar Gas Sampling Bags
Tedlar gas sampling bags are made from DuPont® Polyvinyl Fluoride (PVF) film. These bags can collect many gases, including permanent and organic vapours. Tedlar bags help analyze air pollutants such as VOCs, carbon monoxide (CO), hydrogen sulfide (H₂S), sulfur hexafluoride (SF₆), methane (CH₄), mercaptans, and radon. They are useful in high-temperature areas like industrial stacks and chimneys. Their heat resistance makes them ideal for flue gas sampling.
Each bag has two main parts: a PVF film body and a valve fitting. The valve can be made of Teflon/PTFE, stainless steel (SS), or polypropylene (PP).
- Stainless steel fittings: Work up to 107°C (224°F), limited by the O-ring’s heat tolerance.
- Polypropylene fittings: Can handle up to 93°C (199°F), but high temperatures may weaken the fitting.
Tedlar film has a very low gas permeability. It prevents sample loss and keeps gases pure. The film is chemically inert, meaning it does not react with common gases like carbon monoxide, sulfur dioxide, hydrogen sulfide, radon, and mercaptans. This helps maintain sample integrity and is ideal for gas sampling. Tedlar film is strong and resistant to damage. It works in extreme temperatures from –72°C to 107°C, making it useful for many industries. The film can be reused by cleaning it with gas flushing. It comes in different types to suit various gas sampling needs.
Applications in Gas Sampling and Analysis
Tedlar gas sampling bags keep gas samples pure in many fields. Studies show they are effective in different applications. Tedlar bags are useful for odour testing in environmental management. Medical research stores human breath samples to keep them fresh and unchanged until the health test and air monitoring. For chemical and ecological studies, scientists use them to capture volatile organic compounds (VOCs) for mass spectrometry. Though some gases may slowly pass through the material, and minor contamination can occur, they are still preferred for collecting non-polar hydrocarbons, CO₂, N₂, and organo-sulfur compounds. They are widely used in petrochemical industries, pollution control, and power plants.
Tedlar bag’s strength, low permeability, and chemical resistance make them reliable for workplace safety, air pollution checks, and emissions monitoring. To avoid problems and ensure best performance, use standard procedures.
Advantages and Limitations of Using Tedlar Bags
Tedlar bags are strong, resistant to chemicals, and prevent contamination, as they are made from polyvinyl fluoride (PVF) film. These bags can handle extreme temperatures, are reusable, and are easy to clean. They collect non-polar hydrocarbons, inert gases, sulfur compounds, and VOCs. Apart from these advantages, they are also cheaper than FEP or PFA bags, thus recommended by the Environmental Protection Agency.
Tedlar bags also have some limitations. Light gases like hydrogen and helium can pass through. Some compounds may stick to the bag or mix with background chemicals. Moisture can cause condensation, making them unsuitable for reactive or polar compounds. Tedlar bags are suitable for short-term gas sampling. It is not ideal for long-term storage or highly reactive gases. Rigid canisters or multi-layer foil bags are used for such sampling.
Handling and Storage Best Practices of Tedlar Bags
Do not overfill Tedlar bags during air transport. Keep them at about 50% capacity to reduce the bursting risk due to pressure change. Always collect duplicate samples for necessary tests to avoid loss or contamination. Notify the lab immediately after collection and send the samples the same day. Avoid collecting samples on or before holidays to prevent delays. Depending on the sample, the holding time is usually 24 to 72 hours. Analyze samples within 12–48 hours for the best results.
Use flexible tubing or a proper fitting to connect the bag securely to the sampling port while collecting the sample. Consider potential losses if using a personal pump. Open the valve slowly, fill the bag to half capacity, then close it tightly. After disconnecting, label the bag clearly. Keep the bags away from UV rays to maintain sample quality, as it can degrade certain compounds. Generally, sample bags don’t require cooling during transport, but for precaution, place them in an insulated, rigid and opaque shipping container to prevent punctures and environmental exposure. Follow chain-of-custody procedures to track samples throughout transport and analysis.
Gas Sampling Bags Material Comparison
| Property | Tedlar | ALTEF® | Multi-Layer Foil |
| Material | Polyvinyl fluoride (PVF) film | Specialized polymer designed for gas sampling | Laminated foil with multiple layers |
| Thickness | 0.002 inches | 0.003 inches | 0.0046 inches |
| Specific Gravity | 1.70 g/cc | 1.78 g/cc | 1.09 g/cc |
| Tensile Strength | 8100 psi | 6100 psi | Not provided |
| Max Working Temperature | Up to 400°F (205°C) | Up to 302°F (150°C) | Up to 190°F (90°C) |
| Permeability | Lower than ALTEF® but higher than foil | Higher than Tedlar® | Extremely low (high barrier properties) |
| Chemical Resistance | Works well with most gases | Resistant to acids, organic compounds, chlorinated solvents, and alcohols | It has strong protection against moisture and reactive gases. |
| UV Resistance | It has a good UV resistance | It exhibits lower resistance to UV exposure | It blocks UV rays completely |
| Potential Contaminants | May have traces of Dimethylacetamide and phenol | Little to no Dimethylacetamide or phenol | No known contamination issues |
| VOC Detection | Commonly used for Volatile Organic Compounds | Works well for VOCs and sulfur compounds | Less effective for very low VOC levels |
| Compatibility with Reactive Gases | Less reactive, widely used in EPA testing | Not ideal for high concentrations of ketones and esters (>30%) | Excellent for hydrogen sulfide (H₂S) and low-molecular-weight gases |
| Sustainability | Strong, resists punctures | Moderate | Leak-resistant but not very flexible |
| Sample Shelf Life | Short-term (up to 72 hours) | It lasts longer than most polymer bags | Can hold samples for up to 5 days |
| Cost & Availability | Getting costly because of worldwide shortages | Economical and readily available | Readily available but requires special handling |
| Applications | General-purpose gas sampling where permeability control and durability are required | VOC and sulfur compound sampling with minimal background interference | Long-term storage of reactive gases like H₂S and protection from UV exposure |
Conclusion
Tedlar is a registered trademark of DuPont Company and is used to manufacture gas sampling bags. Tedlar gas sampling bags are strong, have low permeability, and do not react with most chemicals. They are used for collecting and analyzing different gases for short-term sampling in environmental monitoring, industrial hygiene, and research industries. They work well for VOCs, sulfur compounds, and industrial emissions. They can resist heat and are reusable. As a limitation, they allow some light gases to pass through and can retain traces of previous samples. Compared to other options, Tedlar bags offer a good balance of strength, chemical resistance, and cost-effectiveness. Proper handling and storage are essential for optimum results.
To get quality products and original Tedlar bags, contact a trusted supplier. To know more about the uses and benefits of Tedlar bags, connect with Techinstro today.
