Comparison sample bags

Close up polypropylene fitting

Below is a comparison of three different gas sample bags which we have availabe; the Tedlar bags, FEP (Teflon) bags and Multi Foil Bags. Besides these bags we can also deliver Kynar (PVDF) and Nalophan bags.

If you want to receive a quotation or if you have any questions, please contact us.

 Tedlar bagsFEP BagsMulti-Layer Foil Bags
Properties• Low gas permeation levels for most gases.
• High tensile strength.
• Withstands temperatures up to 82 °C (180 °F) with polypropylene valves or 202 °C (397 °F) with stainless-steel valves.
• Developed specifically for gas sampling applications.
• Chemically inert to most acids, aliphatic and aromatic organic compounds, chlorinated solvents, and alcohols.
• Max. operating temp: 82 °C (180 °F).
• Ideal for collecting low molecular weight
compounds such as CH₄, H₂S, CO, and CO₂.
• Foil layers provide very low permeability and a complete moisture barrier.
• Opaqueness protects samples from ultraviolet light.
• Max. operating temp: 82 °C (180 °F).
Advantages• Recommended in many EPA testing methods.
• Bags resist puncture in the field.
• Only bag available with stainless-steel valves.
• Unaffected by the chemical components of commonly sampled gases, such as carbon monoxide, sulfur dioxide, hydrogen sulfide, radon, and mercaptans
• Suitable for sampling most VOCs and many sulfur compounds.
• Low VOC background.
• Does not exhibit background levels of dimethylacetamide (DMAC) or phenol as Tedlar material does.
• Lower permeability than Tedlar bags to CO₂, N₂, and CH₄.
• The only bag material that adequately holds H₂S.
• Ideal for collecting low molecular weight compounds.
• Very low permeability to O₂ and CO₂.
• Good VOC stability.
Limitations• Exhibits background levels of dimethylacetamide (DMAC) and phenol.
• High permeation rate for CO₂.
• Relatively high permeation rate for O₂.
• More permeable to most compounds than Tedlar bags.
• Not suitable for sampling ketones and esters in high concentrations (>30%).
• Less resistance to UV light than Tedlar material.
• Many sulfur compounds should be analyzed within 24 hours.
• Not recommended for collecting low ppm to high ppb VOCs due to
background levels from bag materials.
• Recommend analyzing within 48 hours after collection for CH₄, H₂S, CO, and CO₂.
Compositionpolyvinyl fluoride (PVF) polymer resinProprietary polyvinylidene fluoride
(PVDF) film
5-layer barrier minimizes gas permeability. – 60 gauge nylon (outer layer) – Metalized aluminum – Polyethylene – 0.0003″ aluminum foil – 0.002″ polyethylene (inner layer)
Thickness0.002"0.003"0.004"
Tensile Strength8000 psi6100 psi19 lb/in
Max. Pressure~2 psi (~ 0.14 bar) or ≤80% filled~2 psi (~ 0.14 bar) or ≤80% filled~2 psi (~ 0.14 bar) or ≤80% filled
Max. Operating
Temp.
Withstands temperatures up to 82 °C
(180 °F) with polypropylene valves or
202 °C (397 °F) with stainless-steel valves
82 °C (180 °F)82 °C (180 °F)
Specific Gravity1.7 g/mL1.78 g/mL1.09 g/mL
Oxygen Permeability50 cc/m²/day58 cc/m²/day0.0078 cc/m²/day
Water Vapor
Permeability
9–57 g/m²/day12–15 g/m²/day0.0078 g/m²/day
Carbon Dioxide
Permeability
172 cc/m²/day172 cc/m²/day0.0078 cc/m²/day

Close up polypropylene fitting Tedlar bags 

Close up PTFE fitting Teflon bag FEP bags 

 Multi-Layer Foil Bags