Nanomaterials divide roughly into two main categories: ambient (or "natural") nanoparticles, and engineered/manufactured nanomaterials. Ambient nanoparticles are also known as "ultrafine" particles in standard industrial hygiene terminology. Sources include diesel engine exhaust, welding fumes, and other combustion processes. Most grinding and crushing processes are incapable of producing nanoparticles, unless fine bead mills are used. Ultrafine/nanoparticles have a larger surface area per unit volume than an equal volume of same composition larger particles. This can lead to different physical, chemical, and biological response properties. Engineered or manufactured nanomaterials are deliberately created and used for a structural/functional purpose. Engineered nanomaterials can include both homogeneous materials and heterogeneous structures with specific applications in computing, medicine, and other disciplines. Examples of engineered nanomaterials include: carbon buckyballs or fullerenes; carbon nanotubes; metal oxide nanoparticles (e.g., titanium dioxide); and quantum dots, among many others.

Nanomaterials have a larger surface area to volume ratio compared to larger materials of the same composition. Nanomaterials, like many other solids, can have biological impacts based on their structure. Inhalation is the most likely exposure route in laboratory settings, and the most extensive health effects studies have involved the inhalation route.

As with all potential exposures, the best place to start is the OSHA "hierarchy of controls", which goes from engineering controls to work practice controls to personal protective equipment. Engineering controls always come first, since they have the potential to remove the exposure from the work area.

Engineering Controls

• Work with nanomaterials in ventilated enclosures (e.g., glove box, laboratory hood, process chamber) equipped with high-efficiency particulate air (HEPA) filters.
• Where operations cannot be enclosed, provide local exhaust ventilation (e.g., capture hood, enclosing hood) equipped with HEPA filters and designed to capture the contaminant at the point of generation or release.

Work Practice Controls

• Provide handwashing facilities and information that encourages the use of good hygiene practices.
• Establish procedures to address cleanup of nanomaterial spills and decontamination of surfaces to minimize worker exposure. For example, prohibit dry sweeping or use of compressed air for cleanup of dusts containing nanomaterials, use wet wiping and vacuum cleaners equipped with HEPA filters.

Personal Protective Equipment

• Provide workers with appropriate personal protective equipment such as respirators, gloves and protective clothing.
• HEPA filtration systems on ventilation systems could remove more than 99.97% of airborne nanomaterials. Similarly, properly fitted elastomeric respirators with HEPA cartridges should be able to prevent respirable exposure to airborne nanomaterials.

All nanomaterial waste should be handled as chemical waste. Contaminated solid waste (paper, gloves, wipes, tips) should be collected and submitted using the online chemical waste pick-up form available on the RMS website.