Tedlar is recommended in several US EPA methods for sampling VOCs and sulfur compounds. Our Tedlar is made from a high-quality 2 mil Tedlar film for superior inertness, impermeability, sample integrity and good recovery data. Our valve and seam-sealing process ensure that these bags are sturdy and virtually leak-proof, even under the most demanding sampling and shipping conditions. Note about bag supply: Tedlar film was discontinued by DuPont in March 2009 for manufacturing into gas sampling bags. Tedlar gas sampling bags will no longer be available, we have a wide variety of sizes available, supplies are limited.