What is Nanoparticular Zinc Oxide and why is it safe in sunscreen?

Zinc oxide is a mineral that used in sunscreen as an active ingredient in blocking harmful sun rays. When applied it settles on the skin without penetrating and works by scattering and reflecting the sun’s UVA, UVB and UVC rays. Nano particular refers to the size of the zinc oxide molecules. A nanometre is a billionth of a metre. A nanoparticle is a particle that is smaller than 100 nanometres.

Studies have already shown that nanoparticles of zinc oxide do not pass through the skin barrier and therefore do not pose a health risk. The same is true of non-nano zinc oxide particles that are larger than 100 nanometres.

Sunscreen is considered one of the best ways to protect skin from sun damage caused by excessive UV exposure. It primarily helps to reduce the risk of skin cancers and premature skin ageing. It typically comes in lotion form that allows for easy spreading on exposed skin.

There are two main types of sunscreen. Those made using mineral ingredients like titanium dioxide and zinc oxide that work by blocking and scattering harmful UV rays before they have a chance to penetrate. And, those made using chemical ingredients like octisalate and oxybenzone that absorb the UV rays before they can damage skin cells.

While both types of sunscreen can be effective in preventing UV radiation from harming the skin, mineral-based sunscreens tend to have an edge as they offer less chemical exposure. Even nano particular zinc oxide has been found to be safe for use in sunscreen as undamaged skin is an effective barrier against its penetration, meaning no or negligible amounts of the molecules can penetrate.

What makes ZnO nanoparticles so special?

When buying sunscreen, you will find that there are two options available. There are mineral and chemical-based sunscreens. Both are effective at protecting human skin from the damaging effects of the sun’s rays. Too much exposure to sunlight can cause the skin to age and increase the risk of developing conditions like skin cancer.

Zinc oxide (ZnO) nanoparticles are considered special and the preferred active ingredient for sunscreen because of their ability to reflect, scatter, and therefore block the sun’s rays. their effectiveness in sun protection has made them a popular sunscreen ingredient for many years.

In addition, despite their very small molecular structure, these nanoparticles are safe for application to the skin. They do not cross the skin barrier. When applied, the particles rather sit atop the surface of the skin, from where they act to block UV rays. Various studies have shown that there is no or negligible amount of particles that can penetrate the skin.

Zinc oxide nanoparticles have also been found to have strong microbial resistance. This makes it beneficial for use in the medical field. It is used extensively in such work as drug delivery, biological labelling, biological sensing and nanomedicine.

These particles have also been found to have various antibacterial, anticancer, immunomodulatory and antioxidant effects. This has promoted their use in various aspects of biomedicine as a means of harnessing their therapeutic benefits. However, as zinc oxide nanoparticles are still a relatively new material in the field of biomedicine, more research is still ongoing to ensure their use does not lead to adverse effects.

Are nano zinc oxide particles dangerous to my skin?

Various studies on nano zinc oxide have been conducted by agencies such as the Food and Drug Administration and the European Union. This is besides other academic and scientific research papers that have been published from different countries. The general consensus from this research indicates that nano zinc oxide is not dangerous to the skin. Its therapeutic benefits help to protect the skin.

The sun is a rich source of vitamin D for the body, but also carries the risk of harmful damage when there is overexposure. Nano zinc particles are used as an active ingredient in many sunscreen products used to protect against overexposure to the sun’s damaging UV rays. When sunscreen lotions that contain nano zinc oxide are applied to the skin, the particles settle on top of the surface. They are not absorbed into the body. From this position, they reflect and scatter the sun’s rays, working to effectively block sun damage.

There has been concern that the very small sizing of these particles may make them capable of crossing the skin barrier and entering into the bloodstream. Research has however shown that the risk of this occurring is either non-existent or negligible. Undamaged human skin is an effective barrier to nano zinc oxide. The same can however not be said of aerosolised products that contain nano zinc oxide. Where there is the risk of inhalation, the use of both nano and non-nano zinc oxide is discouraged as lung tissue does not easily clear small particles and may allow their passage into the bloodstream.