The IOM Method for Sampling Inhalable Dust

Particulate, Dust, Silica, Asbestos, Mists, Diesel Particulate

Inhalable dust is that fraction of particulate matter with sizes up to 100 um in diameter that is inhaled through the nose and mouth. Why is this important?

Employees working in industrial and laboratory environments may be exposed to dust particles which are biologically active and could be hazardous when inhaled into the nose and mouth. The complete capture and accurate measurement of these particles is critical to a safe working environment.

Samplers that measure respirable dust have been available for a number of years. However, conventional 37-mm cassette monitoring is suspected of underestimating the concentration of inhalable dust. Large dust particles that are able to enter the nose and mouth may not be collected, and if they are, they may be deposited on the walls of the sampler. This dust is typically not included in the analysis.

The Institute of Occupational Medicine (IOM) in Edinburgh, Scotland, apparently took these considerations very seriously and developed a new sampler called the IOM. It has been designed to collect inhalable dust and offers an uncomplicated method of sampling and analysis.

The molded cassette has a 15-mm diameter inlet and is used with a standard personal sampling pump operating at two liters per minute. Inside the cassette is a 25-mm PVC filter. Analysis is performed by weighing the entire cassette and filter, incorporating into the test results all particles that have been collected during sampling, both on the filter and on the inside walls of the cassette.

Galson Laboratories is on the leading edge of this technology, analyzing IOM cassettes for a major pharmaceutical company. We gravimetrically determine the amount of particulate collected, desorb the filter, and analyze the extract by high-performance liquid chromatography (HPLC) to identify specific analytes. Timely and accurate reporting of this information to our client company allows it to maintain a safe working environment for its employees.

If you would like more information about IOM sampling, please contact us at 888-432-5227, ext. 305.