When you run your fingers over or through a powdered product that feels as luxurious as silk, it’s hard to think it could be dangerous. But if the product in question is made with nanoparticles, it could be very dangerous indeed.

Nanotechnology refers to the study and application of extremely small things, and we mean small: a nanometer is one billionth of a meter. In other words, there are 25,400,000 nanometers in an inch. A sheet of newspaper is 100,000 nanometers thick. A human red blood cell measures between 6000-8000 nanometers across. 

Because microscopes that allow us to see to the nanoscale were only invented about 30 years ago, nanotechnology is a relatively new science. Since smaller particles allow for smoother application and coverage of cosmetics, some manufacturers jumped immediately on the bandwagon and began using nanoparticles in the formulation of their products. Unfortunately, not a lot of research has been done on the long-term health impact of particles that have been micronized (made smaller) to the nanoscale. 

A 2014 analysis of nanotechnology research concluded that, although nanoparticles don’t seem to be absorbed into healthy skin, studies are lacking as to absorption into skin with impaired barrier function; this means that skin that is broken through eczema, psoriasis, dryness, cuts and scratches or even acne may allow penetration of particles. It is also clear that nanoparticles do penetrate skin through hair follicles and skin pores, with a minimal amount found below the stratum corneum (outer layers). 

The 2014 analysis stated that we need to research whether nanoparticles can be absorbed into the blood stream to reach our organs. In other words: we don’t yet know the answer to that question. Companies that suggest that nanoparticles are not absorbed into the bloodstream are making statements that aren’t based on scientific fact, because the studies simply haven’t been done. 

What is clear from the studies is that should nanoparticles be absorbed into the bloodstream or if they are eaten (licked off your lips), they could cause organ toxicity or be harmful to unborn children. We also know that if nanoparticles are inhaled (through use of powders), they could imbed into lung tissue and cause damage. As small as they are, nanoparticles may cross the blood-brain barrier to reach the central nervous system. In fact, research shows that silica nanoparticles trigger free radical damage and brain cell death, and is a potential risk factor for neurodegenerative diseases.

Likewise, research shows that some ingredients used in cosmetics may come with unintended consequences: the same concentration of silver nanoparticles used in cosmeceuticals for their antimicrobial activity, for example, is also lethal for fibroblasts (skin cells that make collagen) and keratinocytes (skin cells that help to form tight junctures with nerves and have an immune system role). Do you really want to destroy and prematurely age your skin for the sake of a nanoparticle? Other nanoparticles are coated in silicon or preservatives, and it doesn’t have to be recorded on the ingredient label. So-called pure mineral lines may not be so pure after all. 

The bottom line is that we don’t know enough about the health impact of nanoparticles to be carelessly including them in cosmetics, skin care and beauty products.