SPF stands for Sun Protection Factor. In theory, an SPF 50 sunscreen would allow users to stay out in the sun fifty times longer than they normally could without sunscreen, while SPF 30 would imply that users can stay out thirty times longer before getting sunburned. But for high SPF sunscreens, theory and reality are two different things.
People often assume that they are given almost twice the amount of protection by applying an SPF 50 sunscreen compared to one that has SPF 30. This is not true, since the extra protection offered by a higher SPF value is negligible after SPF 15. Properly applied SPF 50 sunscreen blocks 98 percent of UVB rays, while an SPF 30 sunscreen blocks 97 percent of sunburn rays – the difference being one percentage point.
What is the problem with high SPF sunscreens?
Stating an SPF number higher than 30 on a sunscreen is a sales trick luring people into a false sense of security. So, let’s dive into some of the research that has been conducted on the topic.
An SPF test conducted of Procter and Gamble illustrates the problem of high SPF: they tested a sunscreen with SPF 100 at five different laboratories. It turned out that the SPF results varied between SPF 37 and SPF 75 (interestingly the sunscreen was not tested as SPF 100 at any of the labs). The explanation was that minuscule differences in testing conditions can dramatically change the result. For instance, a 1.7% change in light transmission can result in a measured SPF of 37 instead of 100, and small variations in the amount of sunscreen applied can result in similar discrepancies between test results. Because the SPF scale is non-linear, the fluctuation in test results become higher the higher the SPF.
What is the difference between UVB and UVA rays and why does it matter?
A product’s actual sun protection is determined by its ability to protect you from both UVB and UVA rays. UVB rays make you tanned, and too much exposure to them has been correlated to the emergence of skin cancer. UVA rays suppress the immune system, lead to the creation of harmful free radicals in the skin, and exposure to them may also lead to skin cancer. Unlike UVB rays, UVA rays do not make you tanned or redden your skin. Therefore, it is impossible to know whether you have been exposed to a risky amount of UVA rays.
The problem with high SPF sunscreens is the fact that the SPF value has little to do with a product’s ability to shield the skin from UVA rays. Since the chemical compounds many sunscreen manufacturers use for sun protection do not mix well together, SPF 50 sunscreens are often unable to protect the user from harmful UVA rays. Zinc Oxide – the compound used in Suntribe’s sunscreen – is a mineral UV filter that offers natural protection against both UVA and UVB rays.
Health risks associated with high SPF sunscreens
High SPF products may come with significant health risks, since the concentration of UV-filtering chemicals is much higher than in products with lower SPF values. Some of the ingredients used in SPF 50 products have been linked to tissue damage and hormone disruption, while others can trigger allergic skin reactions. Since high SPF products compared to SPF 30 and lower, have not been shown to provide significantly more sun protection, the higher exposure to potentially harmful chemicals does not seem to be worth it. Therefore it makes a whole lot of sense to choose a sunscreen with a lower SPF that will protect you from 97% of UVB rays, and has the ability to shield you from harmful UVA rays also.
High SPF sunscreens and the environment
Since an SPF value above 30 can only be achieved through either adding chemicals to the formula or by using Titanium Dioxide and/or Nano Zinc Oxide (both of which are not as safe for the environment and the skin as Non-Nano Zinc Oxide), high-SPF sunscreens don’t only have the aspect of harming human health, but can also be a threat to the environment. When sunscreen is applied and you go swimming in the ocean or you take a shower, it washes off your skin and ends up in your surroundings. This for example could be coral reefs, on your summer vacation at the beach, threatening their health by bleaching their tissue and endangering the integrity of ocean life. Keep in mind that waste water ends up in the environment also and therefore the chemicals within.
The future of SPF
As a final case in point, it is worth mentioning that the EWG – a non-profit environmental research organisation specialising in sunscreen products – are of the opinion that manufacturers should stop selling high SPF products altogether. Australian authorities have already put a cap on SPF values at 30, and European and Japanese regulators at 50. Even though such policy decisions have not yet been implemented in the USA, the FDA is currently working towards implementing similar caps.
For these reasons, Suntribe only offer SPF 20 and SPF 30 sunscreens, with Non-Nano Zinc Oxide as a natural, mineral UV-filter. Our sunscreens are a lovely mix of that and organic oils, butters and waxes to grant you a smooth consistency, water resistance, protection from 94 to 97% of all UVB rays, plus superb protection from UVA rays. At Suntribe, it is our mission to provide you with worry-free sunscreens.