The Therapeutic Goods Administration (TGA) recently reviewed sunscreen ingredients and tightened the status of two “endocrine disruptor” chemicals.<\/p>\n
These types of chemicals may affect our hormones if we are exposed to high doses.<\/p>\n
Since then, people have been posting concerns on social media \u2014 particularly parents worried about putting sunscreen on their children.<\/p>\n
So is there any cause for concern, and are there any sunscreens you should avoid? Let’s take a look at the evidence.<\/p>\n
What are endocrine disruptors?<\/p>\n
Endocrine disruptors are substances that interact with our hormonal system, which is also called the endocrine system.<\/p>\n
Frederic Leusch, who studies environmental toxicology at Griffith University, says the endocrine system is one of the body’s messaging systems.<\/p>\n
It transmits messages using chemicals, or hormones, that can affect things like growth, metabolism and sexual function.<\/p>\n
<\/p>\n
BPA has traditionally been used in many everyday plastics, and has a structure that resembles natural eostrogen. (Unsplash: tanvi sharma)<\/p>\n
“An endocrine disruptor \u2026 is a chemical that unfortunately is able to mimic that message,” Professor Leusch says.<\/p>\n
If a cell encounters an endocrine disruptor, which is usually a molecule with a similar shape to a hormone, it can mistake that molecule for the real hormone and start acting on the wrong message.<\/p>\n
Because there’s a lot of hormonal messaging involved in growth, pregnant people and young children are particularly susceptible to endocrine disruptors.<\/p>\n
Are there hormone disruptors in sunscreen?<\/p>\n
Yes, a couple of commonly used ingredients have been shown to be endocrine disruptors in the lab, but only in much higher amounts than those found in sunscreens we use.<\/p>\n
“The key aspect to any discussion around toxicology and endocrine disruption is: the dose makes the poison,” Professor Leusch says.<\/p>\n
“If it’s a low-enough dose, your body can handle it.”<\/p>\n
The TGA recently reviewed<\/a> seven different ingredients used in chemical sunscreens to block UV light.<\/p>\n Nial Wheate, a researcher in medicines at Macquarie University, says such reviews are a regular part of the TGA’s business.<\/p>\n “The TGA maintains a constant watch on best practice and best advice so that they can inform manufacturers and the public,” he says.<\/p>\n The review found no concerns about five of the seven compounds.<\/p>\n How UV radiation damages skin, and how sunscreen protects us<\/a><\/p>\n For decades, we’ve known sunscreen dramatically lowers a person’s risk of developing skin cancer, with some of the first evidence coming from (aptly) the Sunshine State. This is how it works.<\/p>\n But two substances, called oxybenzone and homosalate, were shown to cause some hormone disruption effects at lower doses than previously seen.<\/p>\n In some studies, for instance, rats exposed to certain concentrations of homosalate<\/a> or oxybenzone<\/a> grew up with malformations caused by hormone disruption.<\/p>\n Neither compound is present in sunscreens at the concentration that causes problems for rats.<\/p>\n But sunscreen-level concentrations did stray above what’s called the “margin of safety”.<\/p>\n The margin of safety is 1 per cent of the smallest amount of a substance known to have an effect, and the TGA uses it as a barrier to ensure medicine doses are safe.<\/p>\n “It meant that we were getting a dose that was starting to raise some flags,” Professor Leusch says.<\/p>\n As a result, the TGA has changed its recommendations on the amounts of oxybenzone and homosalate allowed in sunscreens.<\/p>\n Some manufacturers will need to adjust the amount of these ingredients in their sunscreens.<\/p>\n Other sunscreens may have theirdirections for use changed: they could still be considered safe if you’re only applying them on your face and hands only, rather than your whole body.<\/p>\n So, should we be concerned?<\/p>\n Professor Wheate doesn’t think the TGA’s new recommendations are cause for concern.<\/p>\n “The actual risk is negligible,” he says.<\/p>\n The studies the TGA’s recommendations were based on were mostly done on animals and cells in labs rather than humans.<\/p>\n “A lot of the studies that indicate that sunscreens can [disrupt our hormones] are studies that don’t mimic what happens in the real world,” Professor Wheate says.<\/p>\n The risks of skin cancer far outweigh the risks of hormone disruption, according to the experts. (ABC Sunshine Coast: Grace Nakamura)<\/p>\n University of Sydney pharmacologist Jane Hanrahan agrees.<\/p>\n Professor Hanrahan says oxybenzone and homosalate have both been used in sunscreens to prevent sunburn for decades.<\/p>\n While they weren’t originally subject to the same strict safety testing as newer UV blockers, their long history of use means there are decades of evidence showing their safety in humans.<\/p>\n “There’s been no clear signal that there’s any serious effects in humans,” she says.<\/p>\n Nevertheless, if you’d rather err on the safe side, many sunscreens don’t contain homosalate or oxybenzone \u2014 so check the ingredients list.<\/p>\n What is the safest sunscreen to use?<\/p>\n While all sunscreens are safe from an endocrine perspective, some types of sunscreen may provide you with more peace of mind.<\/p>\n There are two broad categories of sunscreen: “chemical” and “mineral”.<\/p>\n Chemical sunscreens use “organic” (carbon-containing) molecules to absorb UV rays and turn them into harmless heat.<\/p>\n While some older chemicals, such as oxybenzone and homosalate, can be absorbed through skin into our cells, Professor Hanrahan says there is a host of newer ingredients that can’t be.<\/p>\n “A lot of them are much bigger molecules and they have much lower to zero absorption through the skin,” she says.<\/p>\n Because they’re not absorbed into the body, they’re unlikely to cause any health problems.<\/p>\n Consumers warned against relying on cosmetic sunscreens<\/a><\/p>\n As a growing number of “sun protective” make-up and beauty products hit the shelves, experts say there are a few things to keep in mind to ensure you’re properly protected from the sun.<\/p>\n Mineral sunscreens use ingredients like titanium dioxide and zinc oxide.<\/p>\n These ingredients are not endocrine disruptors.<\/p>\n They are also too big to enter our cells provided they’re not in “nanoparticle” form: crushed to the size of a few millionths of a millimetre.<\/p>\n Crushing up particles this small can have a good cosmetic effect for sunscreens \u2014 they produce less of a white sheen \u2014 but at that size, the minerals can be absorbed by the body.<\/p>\n “If people were really worried [about endocrine safety], my advice would be to use a non-nano mineral sunscreen,” Professor Hanrahan says.<\/p>\n While there’s no evidence nanoparticles are dangerous, larger particles are considered safer because they don’t enter our cells.<\/p>\n However, if you are keen on using a mineral sunscreen, make sure it’s not a product that is being reviewed<\/a> by the TGA for SPF protection concerns<\/a>.<\/p>\n The sunscreens that are causing the most concern for SPF testers all use the same base formula, which is a zinc-based mineral formula.<\/p>\n Professor Wheate says people who are particularly concerned could also look for sunscreens that are free of “parabens”, a type of preservative sometimes used in both types of sunscreens.<\/p>\n “People have linked parabens to endocrine disruption as well.”<\/p>\n Should you still wear sunscreen?<\/p>\n Yes \u2014 even if you don’t get sunburnt, and even if you are using other sun protection as well.<\/p>\n With the TGA tightening its rules around ingredients, and the recent problems with SPF testing, some people are wondering if it’s worth applying sunscreen at all<\/a>.<\/p>\n But according to the experts, sunscreen is still a crucial protection against skin cancers.<\/p>\n “Any sunscreen is better than no sunscreen at all,” Professor Wheate says.<\/p>\n Australia has some of the world’s highest rates of skin cancer, which kills more than 2,000 people each year<\/a>.<\/p>\n While it’s a good idea to combine sunscreen with other types of sun protection like hats, shade and sunglasses, these measures are not enough on their own in the Australian sun.<\/p>\n “I can speak from experience that a rash vest and a hat will not always provide you protection,” Professor Wheate says.<\/p>\n Reflection, particularly from white sand, is enough to cause sun damage to your face even if you’re wearing a hat.<\/p>\n<\/p>\n