What are Nanoparticles?

What are Nanoparticles?

This is part of our ongoing series helping consumers better understand chemicals, chemistry, and product formulations. We translate the science, bust the myths, and give you an honest assessment, so you can make informed choices for your family!



What are Nanoparticles?

Nanoparticles are materials that have at least one dimension (e.g. length, width, etc.) in the nanoscale range of 1 nm to 100 nm (1). To give you a sense of how small that is, one nanometer is a billionth of a meter. To give even more context, here are comparisons using more tangible sizes:

  • There are 25,400,000 nanometers in an inch (2).
  • A sheet of newspaper is about 100,000 nanometers thick (2).

What they do:

Nanotechnology is the science of manipulating atoms and molecules. While this scientific study has only existed for about the past 30 years, the use of nanoscale materials dates back hundreds of years when artists used nano-sized gold and silver particles to create the stained glass windows in medieval churches (2).  

While nanoscale materials exist widely in nature (like viruses, volcanic ash, and DNA), synthetically made nanoparticles are a relatively new creation and are becoming increasingly common in everyday products. For example, nano-sized titanium dioxide is used widely in foods like low fat milk, soy/rice beverages, vanilla pudding, powdered donuts, coffee creamer, candies, and gum, as well as personal care products like sunscreen, face creams, and toothpaste (3).

Nanotechnology and the use of nanoparticles goes far beyond cosmetics and personal care products – it’s being applied to everything from engineering to medicine. While the possibilities of nanotechnology sound amazing (like creating more efficient and effective batteries for storing green energy, or building nano-robots that can kill cancer cells or repair the ozone layer), there’s still much to be learned about potential impacts on our health and the environment (4-6).

Why we’re featuring it today:

Nanoparticles are currently included in our Honestly Free Guarantee because the extremely tiny size of nanoparticles (the diameter of a DNA helix is 2 nm), gives them unique properties compared to their natural particle counterparts. For example, a particle that naturally is too big to be absorbed by human skin could be shrunken down to a level where it easily passes through the skin and even penetrates the walls of cells (7). Since plants and animals and humans are built from cells that have never before interacted with these novel nanoparticles, we have little understanding about potential biological or toxicological impacts. We firmly believe this is something that should be comprehensively studied before releasing them into our environment and using them in everyday products. While some other sunscreen manufacturers use nano-sized titanium dioxide and zinc oxide, we only use non-nano zinc oxide in our products.


  1. U.S. Food and Drug Administration. (n.d.). Retrieved March 01, 2016, from http://www.fda.gov/RegulatoryInformation/Guidances/ucm257698.htm
  2. What is Nanotechnology? (n.d.). Retrieved March 01, 2016, from http://www.nano.gov/nanotech-101/what/definition
  3. Weir, A., Westerhoff, P., Fabricius, L., Hristovski, K., & von Goetz, N. (2012). Titanium dioxide nanoparticles in food and personal care products.Environmental science & technology, 46(4), 2242-2250.
  4. Nanotech Batteries For A New Energy Future. (n.d.). Retrieved March 07, 2016, from http://www.sciencedaily.com/releases/2009/03/090320173859.htm
  5. Tucker, P. (2012). Nanobots to Fight Cancer. The Futurist, 46(3), 15.
  6. Sweeney, A. E., Seal, S., & Vaidyanathan, P. (2003). The promises and perils of nanoscience and nanotechnology: exploring emerging social and ethical issues. Bulletin of Science, Technology & Society, 23(4), 236-245.
  7. Verma, A., & Stellacci, F. (2010). Effect of surface properties on nanoparticle–cell interactions. Small, 6(1), 12-21.


We aim to provide you with the most honest and credible information possible. This article was reviewed for accuracy by The Honest Team and was written based on trusted sources that are linked at the bottom of the article.