Health & beauty

Sunscreens test

Updated: 05 Jun 2008
Sunscreens-test-hero

Introduction

We've tested 10 top-selling sunscreens sold over the counter: two of these failed to meet their SPF30+ claim.

Earlier this year we reported that the Cancer Society SPF 30+ trigger spray sunscreen did not provide the "very high" protection it claimed. So we decided to put the claims of 10 more sunscreens to the test. The results are a serious public-health concern.

What we found

The 3 sunscreens that failed their claims

The two sunscreens that failed their SPF30+ claims were Cancer Society Roll-on Sunscreen SPF30+ (65ml) and SunSense Ultra SPF30+ (250ml).

A third sunscreen - Cancer Society Sunscreen with Insect Repellent SPF30+ (100g) - failed its broad-spectrum claim. It let in too much UVA radiation.

Public-health issue

These results are a serious public health concern.

The Australian/New Zealand standard for sunscreens is not compulsory here (although it is in Australia). So sunscreens that are sold only in New Zealand don't have to have their claims tested. That's why we're urging the government to reclassify sunscreens as therapeutic products rather than as cosmetics, so that any claims about protection have to be supported by test evidence.

We also have serious concerns about the Australian testing regime for sunscreens. Because the standard's compulsory on the other side of the Tasman, Australia's Therapeutic Goods Administration requires that any sunscreen product sold there must be tested before it's first released for sale. But there's no requirement to clinically retest the product's actual performance after this initial testing. There should be - to guarantee that a sunscreen manufactured year after year still performs to its original specifications and its SPF claim.

Sunscreens sold in Australia do have ongoing checks on their stability and integrity, to make sure the contents of their active ingredients don't vary over their shelf life. But this information is required for auditing the manufacturing process.

Both manufacturers told us they hold evidence that their products have met the requirements for SPF30+.

Our test results provide a good reason why sunscreen manufacturers should periodically retest the performance of their products.

SunSense is a major Australian brand whose products must comply with the standard. The fact that one of its off-the-shelf products failed to meet its SPF30+ claim says the current requirements of Australia's Therapeutic Goods Administration are failing to protect consumers.

Our test results also raise questions about the stability of the active ingredients in sunscreens once they're stored on shop shelves. (We carefully chose sunscreens for our test that had use-by dates well into 2009 and 2010: they weren't old stock.)

Cancer Society products make up 60 percent of the sunscreens sold here. Three of its products have now failed to meet their label claims. We think the Cancer Society needs to take manufacturing standards for its products much more seriously. It also must urgently recall any products still on sale that failed to meet their label claims.

Keep using sunscreen

Our results don't mean you should stop using high-SPF sunscreen. The products that failed to meet their label claims for SPF30+ still offer high protection. But you must apply enough of the sunscreen - and reapply it as often as the label recommends.

Swimming, towelling dry, and taking clothes on and off can also reduce a sunscreen's effectiveness. (See our separate Sunscreens report for more about how much sunscreen to use and frequently asked questions.)

Sunscreen is a secondary line of defence against the sun's harmful rays. Wearing hats and covering up - as well as limiting your exposure when the sun's high in the sky - are the best lines of defence.

Test results

We bought 10 top-selling products over the counter and sent them to one of the two Australian labs that carry out sunscreen testing for manufacturers. The lab tested our sunscreens to the same requirements as the standard.

UVA and UVB radiation in sunlight contribute to premature skin ageing, damage to the immune system and skin cancer. So we asked the laboratory to carry out two types of test:

  • SPF determination: SPF is a measure of protection mainly against UVB rays, the ones that cause sunburn. SPF testing is carried out on human volunteers (see How sunscreens are tested).

  • Broad spectrum transmission: Broad-spectrum sunscreens protect against UVB - and they also protect against UVA (which penetrates deep into the skin layer but doesn't show up as sunburn). In broad-spectrum testing, the lab measures the proportion of UVA rays passing through a measured amount of sunscreen.


Sunscreens test results table

Guide to the table

Our test was carried out in an independent Australian laboratory. The sunscreens were tested to the Australian/New Zealand Standard AS/NZS 2604: 1998.

  • Products were bought in a supermarket or pharmacy. They are listed in alphabetical order.
  • Price is based on a survey of pharmacies and supermarkets during April 2008.
  • Claims SPF When a product claimed to be water resistant, its SPF was determined after immersion in water for the length of time the resistance was claimed.


The 10 sunscreen products we tested

How sunscreens are tested

The method for determining a sunscreen's SPF uses at least 10 volunteers with skin type 1 (skin which burns and never tans) to skin type 3 (skin which burns and tans moderately). People with darker skin or skin that tans readily aren't used - the test would take too long.

Sunscreen patches are exposed to a lamp

As a first step, the lab works out how long it takes each volunteer's unprotected skin to begin reddening. It then applies sunscreen to a series of patches on each volunteer's back, using the thickness specified by the standard (2mg per square centimetre). This is much thicker than what most people use when they're applying sunscreen.

The patches are then exposed to a lamp which simulates the sun's rays (ordinary sunlight is just too variable). Each patch is exposed at increasing intervals - the first patch would have the shortest exposure and the last the longest.

When the testing is finished, the volunteers wear cover-up clothing until the patches are inspected the next day. On each volunteer, the lab identifies the patch that shows the first clearly visible sign of reddening. It then divides the length of time that patch was exposed to the lamp by the length of time taken for the volunteer's unprotected skin to redden. The resulting number is the volunteer's "protection factor". The SPF of the sunscreen is the average of all the volunteers' "protection factors".

Sitting in a pool as part of the sunscreen test

When a sunscreen claims to be water resistant, the SPF is tested after the volunteers have been in water - a swimming pool or spa pool - for the length of time that the product claims water resistance. The volunteers dry off in the air (no towelling is allowed) and then the SPF is determined by exposing patches of skin to the lamp.

Ethical issues

Soaking in a pool may seem like a nice way to make a dollar, even if you do get a funny tan. But how ethical is it to test sunscreens on human subjects when it's known that over-exposure to ultraviolet radiation is harmful?

We're told that regulatory organisations are well aware of the issues involved and are working towards developing a laboratory (in vitro) test to determine SPF. But testing on humans (in vivo) is currently the best method because it takes into account real-life factors such as skin texture, absorption rates and sweating. No acceptable equivalent to human skin has yet been developed for laboratory testing.

There are measures to protect the human volunteers. Each volunteer must complete a questionnaire and give informed consent. Some people - such as pregnant or lactating women, people taking certain medications, and those with allergies - are excluded from testing. Someone who's taken part in a test must also wait at least two months before taking part in another.

Our view

  • The government must urgently reclassify sunscreens as a therapeutic good and bring in an appropriate regulatory system to make sure sunscreens continue to meet their label claims throughout their product life.

  • The Therapeutic Goods Administration in Australia should make it a requirement that the performance of sunscreens is regularly retested as part of compliance with the standard. That would also protect New Zealand consumers because many sunscreens are sold in both countries.

  • The Cancer Society must tighten up its manufacturing standards.

  • Don't think of sunscreen as your main form of defence against harmful radiation from the sun. Covering up and limiting your exposure to strong sun is more important.


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