These bags are fabricated from 2 mil thick PVF (Tedlar) film, a material that is inert to a wide range of chemicals. Tedlar is manufactured without plasticizers. Can be used for collecting air containing all common solvents and many other classes of chemicals. Bags with dual stainless steel fittings feature hose/valve and replaceable septa units. Bags with patented polypropylene fittings are more economical and combine the hose/valve and septum holder functions into a single fitting. The special TCLP bags have only one stainless steel fitting and are designed to connect directly to the EPA TCLP zero-headspace extractors when the listed adapter is used. Larger bags (up to 100 L) are available on special order.