Sioutas Five-stage Cascade Impactor

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Part Number: 225-370
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Sioutas Five-stage Cascade Impactor Overview

Sioutas Cascade Impactor, for use with Leland Legacy air sampling pump at 9 L/min; separates and collects airborne particles in five size ranges: > 2.5 µm, 1.0 to 2.5 µm, 0.50 to 1.0 µm, 0.25 to 0.50 µm, and < 0.25 µm

The patented Sioutas Cascade Impactor separates and collects ultrafine, fine, and > 2.5-micron airborne particles (five size ranges including > 2.5, 1.0 to 2.5, 0.50 to 1.0, 0.25 to 0.50, and < 0.25 micron. Particles above each cut-point are collected on a 25-mm PTFE filter in each appropriate stage when the Sioutas Impactor is used with a 9 L/min sample pump. Particles less than the 0.25-micron cut-point of the last stage are collected on a 37-mm PTFE after-filter. The Sioutas Impactor is suitable for personal and area sampling indoors and may be used for ambient outdoor sampling with special provisions. Size-fractionated samples can be analyzed gravimetrically, chemically, and microscopically.



    • Industrial hygiene studies


    • Indoor Air Quality (IAQ) studies


    • Air pollution studies


    • Inhalation toxicology and epidemiological studies


    • Aerosol research


    • Pharmaceutical studies


  • Outdoor ambient sampling (requires special provisions, see Operating Instructions).



Performance Profile

Flow Rate 9 L/min
50% cut-point of each stage at 9 L/min
Stage A:   2.5 µm
Stage B:   1.0 µm
Stage C:   0.50 µm
Stage D:   0.25 µm
Recommended After-filter Type 37-mm, 2.0-µm PTFE filter
(Cat. No. 225-1709)
Recommended Collection Filter for Stages

25-mm, 0.5-µm PTFE with laminated PTFE support
(Cat. No. 225-3708)

Wind Velocity < 5 mph
Operating Temperature Maximum operating temperature of PTFE Filters with the PMP support ring is 464 F (240 C)
Maximum Particle Load Varies per stage
Construction Material Stages are anodized aluminum;
O-rings are Buna-N (Nitrile); filter retainers are acrylic
Inlet and Outlet Diameters Inlet: 3/8-in OD and 1/4-in ID
Outlet: 3/8-in OD and 1/4-in ID
Dimensions 3.4 x 2.2 in (8.6 x 5.5 cm)
Weight 5.6 oz (159 gm)
Tubing 3/8-inch ID
Approvals ETV
Back pressure on PTFE filters can vary within the same lot.
The maximum operating temperature for PTFE filters with PMP support ring is 464F (240C).
See NUATRC Report No. 2

  • Sampler Class : Ultrafine
  • Sampler Class : Fine
  • Sampler Class : PM2.5
  • Cut-point : 2.5 µm, 1.0 µm, 0.50 µm, and 0.25 µm
  • Flow rate : 9 L/min
  • Disposable : No
  • Sampler Type : Cascade Impactor
  • Calibration Adaptor? : No

Sioutas Cascade Impactor
The patented personal-size Sioutas* Cascade Impactor separates and collects airborne particles in five size ranges: > 2.5 µm, 1.0 to 2.5 µm, 0.50 to 1.0 µm, 0.25 to 0.50 µm, and < 0.25 µm. When used with PTFE collection filters, the Sioutas Impactor is highly efficient at collecting particles without the use of impaction grease or substrate coatings and at retaining unstable compounds for size-fractionated chemical analysis.

  U.S. Patent No. 6,786,105
* Developed by Dr. Constantinos Sioutas of the University of Southern California in partnership with the Mickey Leland National Urban Air Toxics Research Center (NUATRC).

Sioutas Impactor and Leland Legacy Pump Are Powerful Partners

Use the Sioutas Impactor with the Leland Legacy Sample Pump at 9 L/min to ensure precise particle separation at the specified cut-points. Particles above each cut-point are collected on a 25-mm filter in the appropriate stage with particles below 0.25 µm collecting on the 37-mm after-filter (optional). The small, lightweight Sioutas Impactor simply clips to a worker’s collar or lapel for personal sampling and is also suitable for area sampling. Sioutas Impactor and Leland Legacy ® Pump

ETV Logo
Sioutas Impactor and Leland Legacy Receive ETV Verification
U.S. EPA Environmental Technology Verification (EPA-ETV) is a program that furthers environmental protection by accelerating acceptance and use of improved, cost-effective technologies through performance verification. EPA-ETV tested the SKC Leland Legacy Sample Pump with the Sioutas Impactor and released its report.

ETV Logo performance is verified with Leland Legacy only.


Why Use the Sioutas Personal Impactor?
PM2.5 (fine particulate matter) has been linked to an increase in respiratory symptoms and related hospital visits, aggravated asthma, chronic bronchitis, and premature death. Indoor concentrations of PM are often higher than outdoor concentrations. Studies show that the traditional stationary monitors used for ambient PM measurement are poor estimators of personal PM exposures; they do not assess the effects of PM on vulnerable individuals. The new approach to sampling fine PM includes:

  • Sampling of microenvironments, i.e., personal sampling
  • Sampling of vulnerable persons
  • Measuring the mass of exposure
  • Measuring particle size
  • Evaluating particle chemistry

Only the Sioutas Cascade Impactor meets the new approach to sampling fine PM. The Sioutas Impactor collects personal samples and separates the sample into five size ranges that can be analyzed for particle mass exposure, particle size, and particle chemistry. Analysis of Sioutas Impactor samples can provide data on the relationship between outdoor/indoor PM levels and personal exposures.


Filters for the Sioutas Impactor
The Sioutas uses four 25-mm filters (required) and one 37-mm filter (optional) for sampling. The 25-mm PTFE filters act as collection substrate and the optional 37-mm PTFE filter is the final collection filter (after-filter). SKC recommends PTFE filters• for use in the Sioutas Impactor to minimize particle bounce and preserve unstable compounds. Coated collection substrate may be used if desired, however, a coating is not necessary and can interfere with chemical analysis. See Ordering Information for recommended filters.

• Back pressure on PTFE filters can vary within the same lot.

Misra, C., Singh, M., Shen, S., Sioutas, C., Hall, P., "Development and Evaluation of a Personal Cascade Impactor Sampler (PCIS)," Journal of Aerosol Science, 33, 2002, pp. 1027-1047

Ono-Ogasawaraa, M., Myojo, T., "Characteristics of multi-walled carbon nanotubes and background aerosols by carbon analysis; particle size and oxidation temperature" Advanced Powder Technology. 2012,

Ono-Ogasawaraa, M., Myojo, T., "A Proposal of Method for Evaluating Airborne MWCNT Concentration" Industrial Health, 49, 2011, pp. 726-734

Singh, M., Misra, C., Sioutas, C., "Field Evaluation of a Personal Cascade Impactor Sampler (PCIS)," Atmospheric Environment, 37, 2003, pp. 4781-4793

Sioutas, C., "Development of New Generation Personal Monitors for Fine Particulate Matter (PM) and its Metal Content," NUATRC Research Report No 2, 2004