Some Sunscreens Have A New Mini-Secret

Check the label on a sunscreen for sale in this Whalley Avenue pharmacy aisle, and you’ll get advice for applying it, a warning not to get it in your eyes and a list of ingredients.

You won’t learn whether the lotion contains newfangled super-tiny particles.

That’s a problem, according to consumer and environmental advocates who keep tabs on the burgeoning field of nanotechnology.

At issue are versions of traditional sun blockers titanium dioxide and zinc oxide, shrunk down to make them sheer on your skin. They’re marketed as ​“chemical-free” and ​“mineral-based,” often in formulations aimed at children.

Some experts say these sunscreens represent a safe improvement over blockers that use questionable chemicals. Others believe there’s still reason to be wary.

But in most cases, you won’t know whether the zinc and titanium are the super-small ​“nanoparticle” size, or something bigger. That’s because like many of the more than 1,300 consumer products that contain tiny substances known as ​“nanomaterials,” the label isn’t required to tell you. Read the back of the bottle and you’ll see how much titanium dioxide or zinc oxide is in the preparation, but not the size.

There’s a simple rule of thumb to do your own sleuthing, said Philip Lippel, a member of the advisory board for the NanoBusiness Commercialization Association, an industry group: if it stays white on your skin, it’s not nano. But if it goes on clear, it is.

For many who are watching the rise of nano-related products, DIY investigations are an unfair burden to put on harried parents, anxious athletes or anyone who wants to try and protect themselves from the sun.

“I think the only thing consumers can do — and this is asking a lot — is call companies,” said Carolyn Nunley Cairns, a program leader in product safety in the technical division of Consumers Union, which publishes Consumer Reports magazine. The non-profit consumer advocacy group wants the U.S. government to do more to regulate the burgeoning nano industry.

Nanotechnology leverages super-small particles (a nanometer is a billionth of a meter) to create products with amazing properties. These materials can make better batteries or lighter and stronger bike frames, as well as new medical instruments and medicines that can save lives.

These ​“nanomaterials” are believed to hold great promise for a wide variety of applications. But shrinking these substances can change their properties, and scientists are struggling to figure out whether, how and why that shift can make them dangerous in the process.

As that research continues, a parallel debate is raging: What don’t we know about existing products that might hurt us or our environment? The result is that, as with many controversial chemicals, consumers are getting conflicting messages about what they should and shouldn’t use.

Amid the confusion, U.S. regulators are mostly on the sidelines, even as their European counterparts move toward stiffer labeling requirements.

Going On Clear

Sunscreens are a key example.

Spread some Johnson & Johnson Baby Daily Face and Body Lotion on your arm, and the chalky cream eventually all but disappears on the skin. Duane Reade’s zinc oxide sunscreen proclaims on the label that it ​“goes on clear,” and it lives up to the claim. Without testing, it’s impossible to know the size of the titanium dioxide and zinc oxide particles.

These recipes are increasingly common in ​“chemical-free” sunscreens as an alternative to ingredients such as oxybenzone, which can be irritating to the skin — and about which there’s a whole other set of concerns. Physical sun blockers like titanium dioxide and zinc oxide have been in use for decades, but were less attractive because they were opaque when applied (think the classic white blaze on a lifeguard’s nose).

Shrinking them to the nanoscale makes them go on clear, a big selling point for anyone who’s not interested in looking like a mime. But what does that change do?

Researchers from the U.S. Food & Drug Administration found that nano-sized titanium dioxide didn’t get into the bloodstream of laboratory pigs when they were slathered with sunscreen. A scientist in Australia, however, found that mini-particles of zinc oxide did get into the blood, albeit at minuscule levels.

An Environmental Protection Agency case study released last year estimated that the amount of applied nano-titanium dioxide during a half-day at the beach could be between 8 and 37 milligrams per kilogram of body weight for an average 3‑year-old, depending on the amount applied and the amount in the sunscreen. The estimate for adults was 12 to 55 milligrams per kilogram of body weight.

Without a better grasp of how much, if any, gets through the skin — and what amount is harmful if it does — it’s hard to make much sense of the human impact. There’s even less clarity about what happens to the particles when they wash off, while we’re swimming or when we shower, and the impact on water or soil.

The human health questions recently prompted a local branch of the Australian Education Union to recommend that schools not use nano-sunscreens until more research can settle the issue (click here for a criticism of the move). The organization is also handing out a guide put together by the environmental activist group Friends of the Earth to schools.

FOE has been one of the loudest voices against nano-sunscreens, pressing U.S. regulatory agencies to do more and publishing guidelines for consumers.

“Our position is still that nano-sunscreens are not safe, and potentially could be not healthy for children and especially for the environment and the workers,” said Ian Illuminato, the health and environment campaigner at FOE. ​“I don’t think it’s for certain one way or the other yet. But I do know there’s enough information that they shouldn’t be on the market — and, at a bare minimum, should be labeled.”

Other organizations are less critical. For example, the Environmental Working Group, which is critical of the FDA’s lack of overall regulation of sunscreens, advises against power or spray sunscreens with titanium dioxide and zinc oxide, but cites the lotion-based formulas as ​“among the best of the available sunscreen ingredients for American consumers.”

Illuminato and many others scoff at the idea that titanium dioxide and zinc oxide are advertised as somehow being healthier than other sunscreens. At a recent conference of researchers at Duke University examining the impact of nanotechnology and the environment, participants broke into chuckles when a speaker mockingly noted how these substances are being pushed.

“These are chemicals. There should be no question about that,” Illuminato said. ​“It’s not just somebody grinding a rock.”

These two substances are already in wide use — in nano size as well as in larger formats — outside of the sunscreen business. Titanium dioxide, for example, is used in everything from toothpaste to paint. It’s manufactured in powdered form, and most research indicating health concerns about the material points to inhaling it as the biggest problem.

That’s one of the reasons why Illuminato’s complaints focus on workers as much as consumers and the environment. Industrial exposures are a potential concern for a wide array of nanomaterials, including carbon nanotubes.

To that end, the National Institute for Occupational Safety and Health issued guidelines last month for workplace exposure to titanium dioxide. For the first time, the agency made a distinction between nano-sized particles and larger ones, saying that the accumulated research suggests that the smaller substance could be ​“a potential occupational carcinogen.”

This doesn’t factor into the back-and-forth over sunscreens, since titanium dioxide doesn’t appear to be used in any of the popular spray formulations aimed at kids and the sports-minded.

And yet few rules govern nano and consumer products, unless they make specific claims, such as a keyboard that was advertised as a germ-killer because it’s coated with nanosilver particles. For many products — say, a tennis racket that’s strengthened by carbon nanotubes — there may be little risk. But for cosmetics, including sunscreens, the average buyer is on her own, said Todd Kuiken, a research associate with the Project on Emerging Nanotechnologies at the Woodrow Wilson Center for International Scholars.

Kuiken is pushing for labels on all products containing nanomaterials. PEN hosts a well-used database of consumer products with nano components; the catch, as Kuiken and others frequently note, is that the inventory contains mostly items that advertise the super-small elements. Countless other products don’t mention it, and some companies have even started downplaying nano ingredients as public concerns about the substances grew.

Kuiken said that when he started at PEN three years ago, Kraft Foods had a web page discussing nano and food.

“Now they claim they don’t do it,” he said. ​“They were scared out of it, pretty much.”

Burt’s Bees Backtracks

Questions, and some public pressure, pushed other companies to change their formulations — or simply abandon their claims. One example is Burt’s Bees, a beloved cosmetics line that has built a pristine image as a naturally-sourced manufacturer. One of the company’s sunscreens was listed on the PEN inventory, prompting questions from concerned parents and other customers. These days, the company has an emphatic statement on its web site that it doesn’t use nanotechnology.

Asked for additional details, Celeste Lutrario, vice president of global research and development at Burt’s Bees, said this in a statement from the company: ​“When we entered into the suncare category with our first sunscreen we used a technology that leveraged nano-technology with particle size less than 200nm [nanometers]. After researching scientific studies, following consumer perception, and European regulations on Nano-technology, we decided that there was not enough research to prove or disprove that nano-technology was or was not a health concern. Since we take health very seriously we decided we would no longer use nano-technology in any of our products until we have definitive scientific research that conclusively proves its safety. Our current policy is to use nothing with a particle size smaller than 200nm.”

A loose definition of ​“nanoparticle” is a substance smaller than 100 nanometers, although that remains a source of debate within the scientific and regulatory communities. And it’s unclear whether ​“micronized” titanium dioxide and zinc oxide, as the slightly larger particles are called, are better than their smaller counterparts.

So what’s a consumer to do? Even querying manufacturers might not be enough.

Cairns’ team tested a number of ​“natural” sunscreens, looking for nanoparticles. It found that several products that claimed not to contain nano-sized substances did.

For example, Kiss My Face markets a kids’ sunscreen (pictured) that advertises ​“no nanoparticles” on the label. But Consumers Union’s testing saw them.

“What we found is a lot of people really didn’t think they were using nano,” Cairns said.

It’s possible that these companies genuinely didn’t know, either because their suppliers didn’t tell them or because something happened during the production of the sunscreen. But the testing proves just how hard it can be to pin down what’s got nano and what doesn’t.

CU has pushed for broader regulation of nanomaterials, arguing that the FDA and U.S. Environmental Protection Agency, among others, should be treating super-small forms of already-approved substances as new cases. Illuminato’s group has repeatedly called for similar action, as has the International Center for Technology Assessment, which has filed petitions involving nanosilver and nanosunscreens.

In some ways, the lack of labeling requirements are indicative of the broader problem of regulating nanotechnology: how small is too small? How can we tell the difference between naturally-occurring nanoparticles, and engineered ones? What kind of testing is best for ferreting out the real-world effects of these substances?

These questions are about more than sunscreen. Cairns, Kuiken and Illuminato all said that public pressure is going to be a factor moving forward, much as it has been with the debate over genetically-modified foods.

“It’s interesting to me that the public has this phobia against food products but don’t seem to have the same problem with cosmetics,” Kuiken said.

Nanotechnology can do some remarkable things, Illuminato said. What’s not clear is whether it’s best used in sunscreens — something that not even the companies making them might know.

“Companies are just taking a small piece of that power and we’re getting some pretty crappy products,” he said.

Ultimately, Illuminato said, the smart consumer will rely less on sunscreen and more on old-fashioned advice: spend less time in the sun, and when you do, cover up.

“Unfortunately, the whole issue with sunscreens is very difficult, because of the other things on the market that could be toxic,” he said. ​“I think we really need to redevelop what we put on our skin in terms of sunscreen.”