Chemical Profile: Silver Nanoparticles

What Are They?

Silver nanoparticles are increasingly being used in a number of products. Nanoparticles are extremely small units of a substance. Generally, nanoparticles can be 1000 times smaller than the width of a human hair. However, there is currently no scientific consensus on the  precise size of a nanoparticle. The European Union defines nanomaterials as between 1 and 100 nanometers (along with some other defining features), but a number of organizations recommend that the definition for food ingredients be 500 nanometers and below.


Because of their antifungal and antibacterial properties, silver nanoparticles are often used as preservatives or to kill bacteria in products. Manufacturers like to tout these as a natural option to conventional preservatives such as formaldehyde and parabens. But are they better?

These kinds of particles can be found in “antimicrobial” workout gear and other clothing, period panties, cleaning products, wound healing products, cosmetics and personal care, “antimicrobial” kitchen gear like cutting boards and dishware, baby bottles, drinking water purification systems, medical applications, appliances, baby products like stuffed animals and strollers, and more.

The Health Concern

Despite nanoparticles becoming increasingly common across industries, they have not been properly assessed for human or environmental health effects, nor are they adequately regulated. As of 2017, the EPA has made some strides in regulation, requiring companies that manufacture nanoparticles to notify the EPA. This is a step in the right direction, but is not comprehensive regulation. The result is numerous new and untested nanoparticle technologies hitting the market at an unprecedented pace.

Researchers don’t quite understand the impacts nanoparticles could have on human health and the environment. However, because of their infinitesimally small size, nanoparticles may be more chemically reactive and therefore more bioavailable. The dramatic difference in size can also cause nanoparticles of a substance to behave differently than larger particles of the same substance. The behavior of nanomaterials is very difficult to predict.


Of all of the various types of nanomaterials, nanosilver is amongst the most studied. Silver nanoparticles are linked to toxicity to various types of mammalian cells, demonstrating interference with the proper inner workings of cells. Additionally, in one study, nanoparticle silver demonstrated toxicity among numerous types of cells including human, animal, bacteria, and fungi cells.

Nanoparticle silver is associated with toxicity to aquatic life, including aquatic invertebrates and fish. Because more and more silver nanoparticles are being released into the environment due to growing applications, toxicity to aquatic ecosystems is of serious concern.

One new application of silver nanoparticles is period panties. However, nanosilver may negatively impact the good bacteria that is found within the vagina. More study is needed, and we note that it’s important to recognize that the ability of nanosilver to leach from period panties into the vagina has never been studied; however, the ability of silver to migrate from silver-impregnated clothing has been studied, and researchers have consistently found silver’s ability to migrate.

How to Avoid Them
  • Choose period panties without nanosilver. Some panties contain silver marketed as unable to leach or migrate; avoid these too.
  • Where possible, avoid consumer products labeled as “antimicrobial” or “antibacterial.” These may be treated with nanoparticle silver or another antimicrobials like triclosan.
  • Choose natural textiles like cotton for exercise (and beyond). Exercise clothing, including socks, can be impregnated with silver nanoparticles, especially when labeled as antimicrobial.
  • Look for and avoid silver on personal care, cosmetic, and cleaning product labels. Note that not all ingredients are required to be disclosed on cleaning products, so make sure to choose a product that lists all ingredients on packaging to avoid mystery ingredients.
  • Opt for uncoated kitchenware made of cleaner and green materials like bamboo, glass, stainless steel, wood, and 100% medical grade silicon. If you’re unsure if the product is coated with nanosilver, ask the manufacturer. If it’s marketed as antibacterial, it’s highly likely it has a coating, nanosilver or otherwise.

The post #ChemicalCallout: Silver Nanoparticles appeared first on MADE SAFE.

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