What is nanotechnology?
Nanotechnology is a broad name given to a wide range of technologies and materials that create, manipulate, or use particles that have one thing in common - their size. Nanotechnology includes the manipulation of extremely small particles to produce new structures, materials, and devices.
Nanotechnology (or nanoscience) involves materials that are extremely small and have dimensions roughly between 1 and 100 nanometres (nm). A nanometre is 1 billionth of a metre. To give you an idea of the scale of nanomaterials:
While the exact definition of nanotechnology may vary, most research and studies have concentrated on particles with at least one dimension of less than 100 nm. Health Canada’s working definition of nanomaterial is “any manufactured substance or product and any component material, ingredient, device, or structure if:
For the purposes of this definition:
NOTE: There are many types of nanomaterials - they can be particles, tubes, shells, quantum dots, etc. Other terms used are nanoparticles, nanoobjects, or ultrafine particles. For simplicity, we'll use the term nanomaterials to mean any or all of these types.
- context A piece of paper is about 100,000 nm thick.
- context A human hair is about 70,000 to 80,000 nm.
- context A red blood cell is about 7,000 nm.
- context A virus is about 10 to 100 nm.
- context it is at or within the nanoscale in at least one external dimension, or has internal or surface structure at the nanoscale
- context it is smaller or larger than the nanoscale in all dimensions and exhibits one or more nanoscale properties/phenomena.
- context The term "nanoscale" means 1 to 100 nanometres, inclusive;
- context The term "nanoscale properties/phenomena" means properties which are attributable to size and their effects; these properties are distinguishable from the chemical or physical properties of individual atoms, individual molecules and bulk material; and,
- context The term "manufactured" includes engineering processes and the control of matter.”
What does this document cover?
This OSH Answers document provides a brief summary of the research into nanotechnology. It focuses on the health and safety concerns when workers are exposed during the manufacture and use of nanomaterials. It does not summarize concerns for general exposure to consumers (e.g., when an individual uses a product for their personal use).
Nanotechnology is a field that is quickly changing both in terms of how we use it, and in our understanding of it. If you have concerns, you are encouraged to contact the manufacturer or supplier, or look for research in scientific journals for the latest findings.
For more information, please see:
How are nanomaterials made?
Nanomaterials can be naturally occurring, incidental, and man-made.
Nanomaterials can be manufactured intentionally and specifically controlled to be a particular shape, size and functionality. Man-made nanomaterials are created through specific processes that produce purposely built materials with specific properties. These processes can be "top-down" where particles are milled to be smaller by methods such as etching, laser ablation, sputtering or electro-explosion, or "bottom-up" where the atoms and molecules are arranged to create the nanomaterials. In some cases, the nanomaterials can "self-assemble" such as carbon fragments that assemble into nanotubes.
Ultrafine particle is a term sometimes used to describe nanomaterials that were not intentionally produced - these are incidental by-products of processes, or they occur naturally. Sources of ultrafine particles include:
What makes nanomaterials unique?
Nanomaterials can have characteristics that are very different from when they are in their larger micro or macro (or "normal") form. Often, nanomaterials will be stronger, lighter, more reactive, or conduct electricity differently. For example:
- context Combustion by-products, such as from welding, cooking, burning, diesel exhaust, etc.
- context DNA, enzymes, antibodies, etc.
- context Viruses
- context Volcanic ash
- context Produced by plants and algae
- context Nanomaterials have a higher surface area in proportion to their mass. An increased surface area typically means the particle will be more reactive (such as having an increased biological activity by mass when compared to larger particles). This effect can be either a positive or negative quality. It is a positive quality when the particle displays antioxidant activity or can carry drugs to specific organs or cells. But it can be a negative quality when the effect can increase toxicity, increase the oxidative stress of a cell, or destroy the cell or when it increases the risk of a safety hazard such as explosibility.
- context The magnetic behaviour of some nanomaterials changes.
- context Macro non-metallic substances (e.g., boron) can exhibit metallic properties in nano form (e.g., borophene).
- context Nanomaterials can increase the mechanical strength of materials.
- context Electrical properties such as electrical conductivity may change.
- context Optical properties include when solutions change colour when in nano forms. For example, the macro form of gold in solution is yellow, compared to the nano form which is purple or red.
- context Enhanced catalytic activity or it becomes a catalyst in nanoform.
- context Nanomaterials have different ways of interacting with each other. They can remain free or group together, aggregate, dissolve, or react with other materials.
- context The material may have a higher permeability through biological barriers.
- context Melting temperature changes.
What are some examples of classes of nanomaterials and their use?
Below are some common examples of nanomaterials and how they can be used.
Table 1: Classes of nanomaterials and examples of use
Anti-static fabrics
Lithium-ion batteries
Drug delivery and cancer therapy
Electrolyte additive
High-efficiency catalysis
Thermal stability of materials
Memory devices
High-strength composites
Biosensors
Cosmetics
Anti-microbial wound dressings
Imaging
Solar cells
Nanosilver use - water treatment devices, food storage containers, cosmetic products, and disinfectant sprays.
Sunscreen filters
Self-cleaning glass
Fertilizer developer
Nanocerium oxide is used as a catalyst in diesel fuel to increase combustion efficiency
Medical imaging agents
Light-emitting diodes
Solar panes
High sensitivity sensors
Car manufacturing industry
- context Carbon nanotubes | Carbon
- context Inorganic carbon | Carbon atomic scale, carbon black, carbon dots
- context Metals, metal salts, and metalloids | Silver, gold, iron, copper
- context Metal oxides (e.g., ceramics) and metalloids oxides | Titanium dioxide, zinc oxide, cerium oxide
- context Semiconductor quantum dots | Cadmium selenide, cadmium telluride
- context Organics (e.g., polymeric) | Carbon, hydrogen, and sometimes other atoms such as oxygen and nitrogen. (e.g., hydrocarbon polymers, layered biopolymer) | Drug delivery devices
- context Other classesE.g., metal alloys, nanoclays, tubes of metals/metalloids, and | Zinc selenide, cadmium sulfide, zinc sulfide