An Asbestos Containing Materials (ACM) inspection is meant to identify Asbestos Building Materials and classify them. The following are how materials are identified and if need be analyzed by a certified lab to confirm content:
Visual Recognition– Many common materials can be Visually Identified. The appearance of texture, color, age, and application make some materials easy to identify, for example thermal duct or pipe insulation. This is a very common application and is seen in many homes built prior to 1950.
Lab Confirmation by PLM- Polarized Light Microscopy. If there are materials which are suspect for asbestos content, but can not be identified visually, there are Lab tests which can confirm if it is asbestos containing. Floor tile is often presumed to be asbestos containing, but it can be checked by PLM analysis. A small piece the size of a quarter is all that is needed. A special process is used to prep the sample and determine the presence and concentration of asbestos fibers under a special microscope. If it is above 1% content of asbestos it is considered to be an Asbestos Building Material. PLM Testing is the most commonly used Lab Analysis to confirm content. The cost may range around $80 to $100 in addition to the cost of an inspection.
Lab Confirmation by TEM- Transmission Electron Microscopy.
Occasionally during an inspection there may be materials which have suspect asbestos content but the concentration may be difficult to see or qualify with standard PLM. In this case a larger, more powerful microscope is used which can see and detect very small fibers. An example of TEM use would be for an attic insulation material which can have very low asbestos levels called Vermiculite. Often the best method for Vermiculite testing is by TEM. A sample size of about a pint size Zip-lock bag is needed. The cost for these tests range $150 to $250 in addition to the cost of an inspection.