These particles are found in cosmetics, injections and tattoos. Here’s why you need to worry about nanoparticle safety
By Jody McCutcheon
With the weather heating up, I’ve been looking for a sunscreen. I was amazed, after having tried a few, how they seem to be better than ever. They get quickly absorbed and leave no white residue. When I asked the sales woman whether this meant the products were still effective, she told me that the same active ingredients were used as the old-fashioned chalky white ones. But there was a difference: now the ingredients were in nanoparticle form, meaning the skin absorbs them right away.
For me, this raised an alarm. While nanoparticles (ENPs) today are hailed as the next great advance, brimming with potential applications in fields as diverse as biomedicine, food and textiles, questions linger about nanoparticle safety.
We put this stuff on our bodies, so it should be safe–shouldn’t it? A 2006 Friends of the Earth (FOE) report entitled “Small Ingredients, Big Risk” suggested otherwise. The report argues that in terms of potential health risks, ENPs may be the twenty-first-century equivalent to asbestos.
No Consumer Protection
Watchdogs like FOE have lobbied for consumer protection, but these efforts haven’t translated into consistent federal regulation. As far back as 2004, the United Kingdom‘s Royal Society recommended that ENPs be treated as new chemicals and subjected to stringent testing and consistent labeling requirements. Despite this wise advice, in 2006, the UK government made a bad decision. They said the companies producing nanoparticles could volunteer to report their findings about nanoparticle safety themselves. IF they chose to do so! That only a handful of businesses responded at all is almost comical, and perhaps unsurprising.
The current lax industry legislation means there is insufficient health testing on nanoparticle safety. There’s no labelling, and insufficiently safe nanowaste management. Consequently, the effects of ENPs on human and environmental health, especially long-term risks, are poorly understood indeed. And cosmetic companies may be very well exploiting this knowledge gap.
The same system (or lack thereof) of regulation was also in place for parabens and other chemicals in makeup. Aspartame, asbestos, DDT pesticides and many other products were ‘generally considered safe’ back in the day, but now we all know now how dangerous these are to human health and/or the environment.
Unfortunately, many people had to die or fall ill before regulations were tightened and/or products were pulled. Will the same be true for nanoparticle safety?
Nanoparticle Safety In Cosmetics
Measuring between one and one hundred nanometers (billionths of a metre) in size, engineered nanoparticles are found in a wide range of cosmetic products, including:
Nanoparticles are even in tattoo ink!
Those most commonly used in cosmetics are inorganic, metal-oxide-based ENPs. These include:
- titanium dioxide and zinc oxide (common ingredients in sunscreens due to effective ultraviolet protection)
- inorganic, metal-based ENPs such as silver (common in deodorant for its antibacterial properties)
- organic, carbon-based ENPs such as fullerenes (common in face creams for its anti-aging effects).
These microscopic particles are employed to provide sun protection, improve skin colour and disguise wrinkles. The smaller the ENPs are, the more transparent the beauty creams using them.
Not On The Label
About the only uncontended fact in the literature is that nano-based creams are better than nano-based sprays or powders in terms of nanoparticle safety. That’s because inhaling ENPs is potentially dangerous, especially for those suffering from bronchial conditions. When embedded in lung walls, ENPs are impossible to remove and can cause significant lung inflammation. If they reach the bloodstream, they may cause extensive organ damage. Titanium dioxide is particularly concerning with respect to nanoparticle safety. According to the International Agency for Research on Carcinogens, it may be carcinogenic to humans.
Despite claiming they are safe, companies are seem keen to hid the inclusion of ENPs in their products, thereby preventing consumers from making informed choices. In 2009, Friends of the Earth Australia commissioned tests that discovered ENPs in ten popular brands of cosmetic foundations and concealers, including Estee Lauder’s Clinique, L’Oreal, Max Factor, the Body Shop, Clarins, Dior and Revlon. Yet only Dior mentions anything about ENPs on the label.
Furthermore, seven of the brand products contained penetration enhancers, which may cause ENPs to enter the bloodstream quickly (more on this later). The other three products were powder-form mineral foundations–which, as they can be inhaled, can be very dangerous. It just shows you how unregulated this market truly is.
Nanoparticles and Sunscreens
Unlike other ENP-based cosmetics, sunscreen plays a significant role in cancer prevention. And with the known ENP risk being less than risks from exposure to UV rays, wearing sunscreen is the wise choice. So surely it’s safe, right?
The assumption of nanotechnology safety may be a house of cards waiting to topple. ENPs act in strange, unexpected ways compared to larger materials, exhibiting new or unexpected physical and chemical properties at their smaller sizes, as for example when exposed to heat or moisture. With these new properties come unknown toxicity risks. Existing safety standards don’t always account for this reality.
ENPs in sunscreens are often exposed to heat and water, thus changing their properties. Exposing them to UV light increases the risk of the production of free radicals (charged oxygen particles), and a corresponding rise in the risk of damage to DNA and proteins. Paradoxically, the smaller the ENP, the larger its surface area becomes–which in turn increases the potential for the production of free radicals.
The worst-case scenario is that ENP-based sunscreens may actually cause skin cancer. This is terrible news (not to mention horribly ironic) for a product that supposedly mitigates cancer risks.
Image: Badger Sunscreens
Do Nanoparticles Penetrate Skin?
The major concern about ENPs in cosmetics is whether they penetrate the skin. If they do, and manage to get inside the human body, they can wreak serious havoc. Most of the limited evidence suggests they don’t penetrate healthy skin (e.g., a study on zinc oxide here), a point on which the EU’s Scientific Committee on Consumer Safety and the US Food and Drug Administration concur.
But given that even non-nano skin creams have been proven to enter the bloodstream, and given that many medicines (think steroids, hormone replacement creams or nicotine patches) are applied via the skin, it seems highly unlikely that nanoparticles wouldn’t get into your system.
At least a few studies suggest there’s minimal penetration of healthy skin (e.g., another study on zinc oxide here). As in the aforementioned FOE Australia tests, evidence shows ENPs may pass through skin exposed to penetration enhancers, which are already found in many cosmetics.
Furthermore, the problem isn’t so much with healthy skin as it is with compromised skin and hair follicles. Some research (such as this study) suggests ENPs may be able to pass through skin that’s wounded or flexed (as during movement). A few studies, like this one, provide evidence that ENPs can penetrate the stratum corneum, but no evidence yet shows they go beyond that. Any ENPs that do perhaps manage to access the deeper, viable layers of skin are too small to be detected; consequently, their effects are unknown.
Ultimately, more studies are required to obtain conclusive results. For now, there is no consensus, and nano safety is still unsure, especially long-term exposure of these particles. But isn’t it better to be safe than sorry?
What If ENPs DO Enter The Human Body?
If ENPs do in fact enter the human body, what then? If they interact with cells, they may change cell structure and cause cell death, as American and Finnish researchers have discovered. Earlier studies similarly suggest that high exposure to cosmetic ENPs can cause DNA and lung damage and cell toxicity, and possibly harm unborn children. Some evidence also suggests cosmetic ENPs cause lung cancer and produce effects similar to those of asbestos when coming in contact with living tissue. No wonder nanoparticles have been called ‘the new asbestos’ by skeptics!
According to a study recently published in ACS Nano Journal, nanoparticle safety is dubious and may cause disease. Specifically, nanosilver may cause the formation of free radicals, leading to cancer, Alzheimer’s and Parkinson’s. But others might argue that the body’s own antioxidant protection helps prevent free-radical formation.
Most recently, researchers discovered that introducing nanoform zinc oxide, cerium dioxide and titanium dioxide to a model human colon significantly changed the gut environment, or the microbial community’s phenotype. The gut’s microbial community contributes to vitamin production, digestion and immune system activity. Disruptions may cause, in the study’s own words, “overall health effects.” However, the study mentions that due to variation between people, these results shouldn’t necessarily be extrapolated over a large population.
Also potentially alarming results on nanoparticle safety are the findings of a 2009 Japanese study. This demonstrated that pregnant mice passed titanium dioxide nanoparticles to their offspring, causing brain and nerve damage and reducing sperm count in males. Sure, mice aren’t humans. And journalists aren’t necessarily scientists. But all this uncertainty around nanoparticle safety screams for more human-based research.
Nanowaste In The Environment
Even if cosmetic ENPs don’t actually penetrate human skin, the story doesn’t just end there. What happens is, they usually get washed off while the wearer is bathing or swimming and enter the sewage system. From there, theoretically at least, they filter through water treatment and end up in the environment.
Yet, according to the literature, cosmetics produce no significant nanowaste. So what does that mean? Our bodies absorb them 100% then? Granted, there’s still plenty of non-disclosure of information regarding nanoparticle safety and the use of ENPs in cosmetic products. And there’s also a corresponding dearth of knowledge of specific ecological damage resulting from ENP use. Few studies exist at all that detail the environmental effects of ENPs from cosmetics or any other products, and the uncertainty is worrying.
Seeing as the cosmetic industry is among the leading users of ENPs, it would follow that cosmetic production generates a great deal of nanowaste. Most of this – following the paradigm outlined above – likely enters the environment, eventually.
Contaminating Food & Water
So, what sort of effects might ENP have on the environment? Nanosilver, for example, with its antibacterial properties, may disrupt the microbial populations of wastewater treatment plants. Silver has been shown to inhibit growth of a bacterium called Pseudomonas fluorescens. This inhibition may compromise the ability of treatment systems to treat wastewater.
From wastewater treatment plants, ENPs may then enter surface water and ground soil. This means there is great potential to disrupt surface environments. For example, fullerenes can cause brain damage in fish and kill water fleas and possibly even bacteria. And a few of the environmental studies that do exist (e.g., here and here) suggest nanoparticle safety is questionable. That’s because there’s proof ENPs that enter ocean water DO harm marine life. They do so by disrupting levels of phytoplankton and disabling defense mechanisms sea urchins use to protect their embryos.
Perhaps the most worrying aspect of nanoparticle safety is this. As more and more ENPs enter the ecosystem, they theoretically could–through processes of bioaccumulation and biomagnification–enter the food chain. From there, it’s a direct route into our bodies, and those of all wildlife.
So What Can We Do?
It goes without saying that additional research on nanoparticle safety will help us understand what damage we’re doing to our bodies and the environment. In the meantime, with so little certainty over whether nanoparticle safety is a sure thing, we’d recommend the following steps:
- Avoid any cosmetic products by large companies like L’Oreal, Estee Lauder, Revlon, Dior, Clarins, Max Factor, etc. They don’t label any of their products as containing nanoparticles, so it’s best to assume that they all do!
- For sunscreen, use organic brands like Green People or Badger. Yes, they will go on white, but you know what? They will block the sun effectively and they won’t hurt your health. Worth it, right?
- Avoid ‘household air cleaning’ spray Pureti. (No one really knows the long-term implications of this spray, yet the corporation that produces it (Unilever) is suggesting we spray high rises with it!)
- Don’t buy ‘nanosilver’ or ‘nano gold’ hand washes, socks, sheets, cutting boards, hair styling tools or other objects. There are really no added benefits to these, and they may harm your health and the planet’s.
- Don’t trust organic companies, either. While in the EU, ‘organic’ means it doesn’t contain GMOs, there’s still no regulation for nanoparticles.
- Check that your preferred brands are not in this database before you buy–some brands you may consider ‘natural’ such as Burt’s Bees or Banana Boat DO use nanoparticles–even in their kid’s sunscreen!
- Educate yourself. A good start is with our Further Reading list, below.