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PTFE (Polytetrafluoroethylene) Membrane Filters

PTFE Filters - Large Pore Size
PTFE Filters - Small Pore Size

The PTFE filters are:

  • Strong and resistant to acids, bases, and solvents
  • Hydrophobic
  • Low background, interference-free chemical determinations
  • Low tare mass for accurate gravimetric analysis
  • Temperature resistant to 260°C (500°F) — autoclavable
  • Ideal for aerosol sampling, especially in environments also containing water vapour
  • 13 mm filter meets NIOSH Method 5517 specifications

PTFE filters are the versatile choice for size-selective samplers. The material’s unique properties make it ideal for gravimetric, chemical, and/or microscopic analysis of sample particulate. PTFE filters are used for aerosol sampling, air venting and gas filtration. Note that the back pressure on PTFE filters can vary within the same lot.

Specific applications include:

Sampling for Particulate Matter:

PTFE filters with a PMP support ring are the recommended filters for particulate matter samplers such as the SKC Personal Modular Impactor (PMI), the Sioutas Impactor, the IMPACT Sampler, the Personal Environmental Monitor (PEM), and the Button Sampler. These filters feature low back pressure which allows longer sampling periods at higher flow rates to enhance sensitivity. See PTFE filters Part No. 225-1709, 225-1747, and 225-1711.

Sampling for Lactic Acid:

The US pharmaceutical industry has designated lactic acid powder as the surrogate particulate to detect fugitive emissions from drug compounding and pill manufacturing. SKC developed a 25 mm conductive polypropylene cassette with 1.0 µm PTFE filter and polypropylene support pad to minimize wall losses and permit in-situ extraction for enhanced recovery of lactic acid at nanogram levels. See PTFE Filter 225-1725.

Sampling for Metalworking Fluids (NIOSH 5524):

PTFE filter Part No. 225-17-33 with a 2.0 µm pore size and laminated PTFE support may be used with the thoracic Personal Parallel Impactor (PPI) to sample thoracic particulate according to NIOSH Method 5524 for metalworking fluids.

PTFE Membrane Filters
Diameter (mm) Pore Size (µm) Support Pad included    Notes Pack Size Part Number
25 0.5 No unlaminated 100 225-17-21
25 1.0 No unlaminated 100 225-17-22
25 2.0 No unlaminated 250 225-3726
25 3.0 No with PMP support ring 50 225-1711   
25 5.0 No unlaminated 100 225-1728A
37 0.3 No For Anthrax/SARS, laminated spun-bound polyester, available in ready-to-use preloaded cassettes 100 225-1722
37 0.45 Yes on polypropylene support 100 225-17-04
37 1.0 Yes on polypropylene support 100 225-17-01
37 1.0 No unlaminated 150 225-3705
37 2.0 No with PMP support ring 50 225-1709
37 2.0 No unlaminated 100 225-17-33
37 5.0 Yes unlaminated 100 225-17P
47 0.5 No unlaminated 150 225-3753
47 2.0 No with PMP support ring 50 225-1747
47 2.0 No unlaminated 150 225-3748
47 5.0 No unlaminated 100 225-1724

Filter support pads available
Recommended for use with the Button Sampler

Preloaded PTFE Membrane Filters

All SKC preloaded filters include support pad and are in SureSeal leak-free cassettes that require a SureSeal Cassette Opener.

Diameter (mm) Filter and Cassette Specifications Pack Size Part Number  
25 PTFE, 1.0 µm with polypropylene pad preloaded in 2-piece conductive cassette, goblet style 50 225-1725  225-1725 Preloaded PTFE Membrane Filters in 2-piece conductive cassette, diameter 25mm, Pore size 1.0 µm 
37 PTFE, 0.3 µm, laminated with spun-bound polyester with cellulose support, unsterilized 3-piece clear styrene cassette, banded; for Anthrax/SARS 50 225-1723  225-1723 Preloaded PTFE Membrane Filters in 3-piece clear cassette, diameter 37mm, pore size 0.3 µm 
37 PTFE, 1.0 µm with cellulose support, preloaded in a 3-piece, clear styrene (traditional style) cassette, banded 50 225-1715  225-1715 Preloaded PTFE Membrane Filters in 3-piece clear cassette, diameter 37mm, pore size 1.0 µm 
37 PTFE, 2.0 µm with cellulose ring, 2-piece plastic cassette, banded 50 225-1713  225-1713 Preloaded PTFE Membrane Filters in 2-piece cassette, diameter 37mm, pore size 2.0 µm 
Cassette Opener, stainless steel, suitable for 25, 37, and 47-mm filter cassettes.
Required for all SureSeal Cassettes.
225-13-5B  225-13-5B SureSeal Cassette Opener, for opening 25 or 37 mm cassettes 
Preloaded PTFE Filters


Preloaded PTFE Filters


Preloaded PTFE Filters


SureSeal Cassette Opener