Back to Basics is a weekly feature that highlights important but possibly overlooked information that any EHS professional should know. This week, we examine the risks of nanotechnology exposure to workers and the guidance the federal government has provided on the topic.
Workers have been exposed to engineered nanomaterials for more than two decades.
According to the Occupational Safety and Health Administration (OSHA), employees who use nanomaterials in research or production processes may be exposed to nanoparticles through inhalation, dermal contact, or ingestion, depending upon how employees use and handle them. The potential health effects of this exposure are not fully understood, but scientific studies indicate that at least some of these materials are biologically active, may readily penetrate intact human skin, and have produced toxicologic reactions in the lungs of exposed experimental animals.
Current research indicates that the toxicity of engineered nanoparticles will depend on the physical and chemical properties of the particle, according to OSHA. Engineered nanomaterials may have unique chemical and physical properties that differ substantially from those of the same material in bulk or macro-scale form. Properties that may be important in understanding the toxic effects of nanomaterials include particle size and size distribution, agglomeration state, shape, crystal structure, chemical composition, surface area, surface chemistry, surface charge, and porosity.
What is it?
The National Institute for Occupational Safety and Health (NIOSH) defines nanotechnology as the manipulation of matter on a near-atomic scale to produce new structures, materials, and devices. The technology has been used to make advancements in medicine, consumer products, energy, materials, and manufacturing.
According to OSHA, examples of materials developed with nanotechnology include the following engineered nanomaterials:
- Carbon buckyballs or fullerenes
- Carbon nanotubes
- Metal oxide nanoparticles (e.g., titanium dioxide)
- Quantum dots, which are nanoscale semiconductor materials (e.g., cadmium selenide)
Examples of products that are produced currently using nanotechnologies include:
- Sunscreens and cosmetics
- Longer-lasting tennis balls and lightweight, stronger tennis racquets
- Stain-free clothing and mattresses
- Polymer films used in displays for laptops, cell phones, digital cameras
- Coatings for easier cleaning glass
- Bumpers and catalytic converters on cars
- Protective and glare-reducing coatings for eyeglasses and cars
NIOSH research
NIOSH’s Nanotechnology Research Center tracks the latest research on the occupational safety and health implications of advanced manufacturing, which includes nanomaterial manufacturing. A 2022 NIOSH publication, Technical Report: Occupational Exposure Sampling for Engineered Nanomaterials, features guidance for workplace sampling for three engineered nanomaterials: carbon nanotubes and nanofibers, silver, and titanium dioxide, each of which have an elemental mass-based NIOSH Recommended Exposure Limit (REL). In addition, NIOSH developed a practical approach to exposure sampling for other engineered nanomaterials that do not have exposure limits.
The Nanotechnology Research Center also has links to a study on the REL for silver nanomaterials and information on the hazards involved with 3D printing, which exposes workers to ultrafine particles.
In addition, the site includes a link to Continuing to Protect the Nanotechnology Workforce: NIOSH Nanotechnology Research Plan for 2018-2025. The 2019 report summarizes nanotechnology research and recommends risk management strategies. NIOSH also has published posters with questions workers should ask before working with nanomaterials and when 3D printing with filament or metal powders.
Relevant OSHA standards
While there aren’t specific OSHA standards relating to nanotechnology, the following general industry standards may be applicable in situations where employees are exposed to nanomaterials:
Recordkeeping (29 CFR 1904)
General Industry (29 CFR 1910)
- 1910 Subpart I – Personal Protective Equipment (1910.32, General requirements; 1910.133, Eye and face protection; 1910.134, Respiratory protection; 1910.138, Hand protection.)
- 1910 Subpart J – General Environmental Controls (1910.141. Sanitation.)
- 1910 Subpart Z – Toxic and Hazardous Substances (1910.1027, Cadmium; 1910.1200, Hazard Communication; 1910.1450, Occupational exposure to hazardous chemicals in laboratories.)
There are 29 OSHA-approved State Plans operating statewide occupational safety and health programs. State Plans are required to have standards and enforcement programs that are at least as effective as OSHA’s and may have different or more stringent requirements.