ISO 10312:2019—Determination Of Asbestos Fibers

A macro photograph fibers of the mineral chrysotile asbestos taken from the host rock with tweezers discovered from ISO 10312:2019 test method.

Asbestos have been used in more than 3,000 products, including ceiling and floor tiles, thermal and electrical insulation, cement pipe and sheet, filters, coatings, brake linings, clutch facings, gaskets, plastics, fireproofing textiles, insulating papers, protective clothing, etc. There are risks associated with asbestos exposure, namely with the inhalation of asbestos fibers. At very high levels, breathing in the fibers has caused asbestosis (a fibrous scarring of the lungs), lung cancer (bronchogenic carcinoma), and mesothelioma (a cancer of the lining of the chest or abdominal cavity). ISO 10312:2019—Ambient Air – Determination Of Asbestos Fibers – Direct Transfer Transmission Electron Microscopy Method specifies a reference method for the determination of airborne asbestos fibers.

Determining Asbestos Fibers

Asbestos is the name given to a group of six different fibrous minerals (amosite, chrysotile, crocidolite, tremolite, actinolite, and anthophyllite) that occur naturally in the environment in certain types of rock formations. These minerals are made-up of long, thin, strong, and flexible fibers that are resistant to heat, electricity, and corrosion, qualities that once made them valuable for various product applications.

Airborne asbestos is often found as a mixture of single fibers and more complex, aggregated structures, which may or may not be also aggregated with other particles. One of the largest potential errors in characterizing asbestos in ambient atmospheres is associated with the variability between filter samples, so it is necessary to design a replicate sampling scheme to determine accuracy and precision. The method specified in ISO 10312:2019 is designed to provide the best description possible of the nature, numerical concentration, and sizes of asbestos-containing particles found in an air sample. Since the best available medical evidence indicates that the numerical fiber concentration and the fiber sizes are the relevant parameters for evaluation of the inhalation hazards, a fiber counting technique is the only logical approach.

What Is ISO 10312?

ISO 10312:2019 specifies a reference method using transmission electron microscopy for the determination of airborne asbestos fibers and structures in a wide range of ambient air situations, including the interior atmospheres of buildings and structures in any atmosphere. Transmission electron microscopy has adequate resolution to allow detection of small fibers and is capable of unequivocal identification of the majority of individual fibers of asbestos. ISO 10312:2019 describes the method of analysis for a single air filter; this method is designed to minimize the disturbance of the collected particulate material and evaluate the effect of those disturbances.

The procedures in the standard allow determination of the type(s) of asbestos fibers present and includes measurement of the lengths, widths, and aspect ratios of the asbestos structures. The standard’s reference method cannot discriminate between individual fibers of asbestos and elongate fragments (cleavage fragments and acicular particles) from non-asbestos analogues of the same amphibole mineral.

How Are People Exposed to Asbestos?

Everyone is exposed to asbestos at some time during their life whether it is at their workplace, community, or home. If products containing asbestos (most products made today do not contain asbestos) are disturbed, tiny asbestos fibers are released into the air. When asbestos fibers are breathed in, they may get trapped in the lungs. Over time, these fibers can accumulate and cause scarring and inflammation, which can affect breathing and lead to serious health problems. Low levels of asbestos are present in the air, water, and soil; however, most people do not become ill from their exposure.

People who become ill from asbestos are usually those who are exposed to it on a regular basis, typically in a job where they work directly with the material or through substantial environmental contact (e.g., miners, insulation workers, automobile brake mechanics). The heaviest exposures today tend to occur in the construction industry and in ship repair, particularly during the removal of asbestos-containing materials due to renovation, repairs, or demolition. Workers may also be exposed during the manufacture of asbestos-containing products, such as textiles, friction products, insulation, and other building materials. Standards like ISO 10312:2019 exist to minimize our exposure to asbestos fibers.