Particle Identification

May 31, 2021

Is there a mysterious substance lingering on surfaces in your property that you would like to identify? Buildings can contain contaminants in settled dust due to numerous reasons. If contaminants are present in the dust, it is important to determine their presence and composition to give you peace of mind and prevent possible adverse health effects. If you are concerned about a mysterious substance settling on surfaces in your property, there are relatively simple methods involving a tape lift or wipe sample that can be used to identify the composition of various particles in dust.

Methods of Particle IDs

We offer two different services of particle identification that involve either an optical analysis using a Polarized Light Microscope or a more in-depth analysis using an Electron Microscope. The identification method using Polarized Light Microscopy is a qualitative method that analyzes the optical properties of materials to determine their presence in the sample. This particle identification is achieved by collecting a tape lift surface sample and sending it to the laboratory to be read using a PLM microscope. The laboratory report will state the materials that were discovered during analysis in percentages of their prevalence.

An electron microscope can also be used to provide a more quantitative and accurate identification of the particles in your home or business. This test is called a Full Particle ID and involves using a wipe surface sample to collect a few square inches of particles that have settled on a horizontal surface. In this method, a Scanning Electron Microscope (SEM) is used to transmit a steady beam of electrons over the sample. The electrons in the light beam will interact with the atoms that makeup the material of the sample. This allows an image to be created and also reveals the chemical composition of the material.

What Particles can be Identified?

These tests focus on determining the contents and compositions of a limited number of particulates that can settle in dust and on surfaces indoors. Some of the materials that can be identified with these methods of analyses are considered to be extremely dangerous and/or can cause severe health effects.

Surface sample particle IDs can identify the following:

  • Man Made Vitreous Fibers (MMVF)
  • Asbestos
  • Mold
  • Biological material
  • Synthetic fibers
  • Hair
  • Minerals
  • Cellulose

Chemical analysis of particles is also possible, but that will be the subject of a future blog post.

When to get a Particle ID Test

You may want to consider particle identification if you recently discovered a strange discoloration or particles appearing on surfaces and you cannot determine its origin. Or, you may have just moved into a new home or office and noticed dust throughout the property that appears out-of-the-ordinary. If this is the case, consider getting it tested to ensure its contents aren’t harmful to your health. 

Here I will highlight a few types of particles that can be harmful to your health. Asbestos was widely used in building materials through the late 1970s and is categorized as a human carcinogen. Particle ID methods can also determine the presence of mold in dust which can lead to allergies and other various health effects. This method can also identify fiberglass fibers, which might be from fraying air duct insulation. It is important to discover possible exposure to these indoor contaminants for the health and safety of the occupants.


If you are curious about a substance settling and accumulating on surfaces at your workplace or in your home, performing a particle ID test could provide you with useful information regarding the substance’s contents, composition and origin. For more information about particle ID testing, contact our offices at 312-920-9393. 

Store, S. A. (2017, October 16). Materials & Forensic Testing. SanAir Technologies Laboratory, Inc.

Other Air Quality Services – Indoor Science – Chicago