Tools & Technologies: Nanomaterials and Fires: Why the Concern?

Every day, more industrial processes are moving to a new, more active form of the materials they use. This new form is 1,000 times smaller than the micrometer-sized materials that have been common in industry for the past 100 years. These new materials...


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Every day, more industrial processes are moving to a new, more active form of the materials they use. This new form is 1,000 times smaller than the micrometer-sized materials that have been common in industry for the past 100 years. These new materials are created by processes that the industry calls nanotechnology and are therefore known as nanomaterials. In some cases, this change is being made to materials that may seem very familiar and carry the same name, but they are much more active, much smaller in size and could be an important factor in responding to a fire or other incident.

Firefighters have always been exposed to nano-sized (ultrafine) particles because the soot generated by fire can be nanomaterial size. This column describes some of the potential safety considerations for fighting fires involving intentionally produced engineered nanomaterials. It should be noted that not all nanomaterials are flammable. In fact, some nanomaterials, such as carbon nanofiber yarns, are designed to be used as fire-retardant materials.

 

What are nanomaterials?

A nanomaterial, as defined by the International Organization for Standardization (ISO), is a material with at least one dimension (length, width or diameter) in the size range of approximately 1 to 100 nanometers (nm). The prefix “nano” means one-billionth; therefore, one nanometer is one-billionth of a meter. This is much smaller than the human eye can see, and individual nanomaterials are visible only with techniques such as electron microscopy.

This does not mean that nanomaterials are invisible; they tend to clump together to form larger particles that can be seen. There are naturally occurring nanomaterials (often termed ultrafine particles) and engineered nanomaterials. Ultrafine particles are nanosized particles that have not been produced intentionally, but are byproducts of diesel engine exhaust and processes such as combustion and welding.

 

What are engineered nanomaterials?

Engineered nanomaterials are designed with very specific properties or compositions such as shape, size, surface properties or chemistry. These characteristics may make them different from larger particles with the same chemical composition. Engineered nanomaterials include a wide variety of chemicals such as metals (silver, aluminum, gold), metal oxides (titanium dioxide, zinc oxide), carbon materials (carbon nanotubes, carbon nanofibers, graphene), quantum dots (cadmium selenide) and cellulose nano fibrils. Scientists and manufacturers use these engineered nanomaterials to create new products, and their use and the demand for them are steadily increasing.

Engineered nanomaterials can be found in many commercial products such as material composites, fuel cells, batteries, touch screens, semiconductors, paints and sunscreens. Already, more than 1,300 everyday commercial products rely on nanomaterials. With an increased number of facilities making or using nanomaterials, it is important for firefighters to be aware of the possible physical hazards in case a fire occurs at such a facility.

 

Pre-incident surveys

Firefighters should perform routine pre-incident surveys at all facilities within their district that present special hazards. Nanomaterials, like combustible dust, should be considered a special hazard because of their unique properties. Firefighters must know in advance which facilities may manufacture and store nanomaterials in order to plan appropriate actions in case of a fire. The Occupational Safety and Health Administration (OSHA) document Firefighting Precautions at Facilities with Combustible Dust provides an excellent overview of how to perform a pre-incident survey and how to develop an Incident Action Plan (IAP). Firefighters should review this document to understand the methodology involved in a pre-incident survey and IAP.

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