Sun creams offer varying levels of protection to ensure optimal defence against the harmful effects of the sun's rays. Some even speak of total sunblock. But does total protection truly exist against UVA and UVB rays? What does this claim, still frequently found on sun cream packaging, actually mean?
What should we make of the term "total sunblock" on sun protection products?
Summary
Published on October 4, 2024, by Stéphanie, PhD, Doctorate in Life and Health Sciences — 3 min of reading
Themes:
Sun protection products: how do they protect us against UV rays?
Sunscreen products (gels, oils, creams, etc.) are a crucial tool designed to mitigate UVA and UVB rays before they reach the deeper layers of the epidermis and dermis. Their sole purpose is to protect the skin from the harmful effects of ultraviolet rays by absorbing, dispersing, or reflecting this radiation.
While the first sunscreens only offered modest protection against UVB and none against UVA, and they were easily washed off by water or sweat, this is no longer the case today. The active ingredients in sunscreens are organic sun filters (chemical absorbers), inorganic (physical blockers) or a combination of both.
Inorganic agents (zinc oxide and titanium dioxide) absorb and deflect UV radiation by creating a layer on the skin's surface, acting as a reflective barrier.
Organic filters directly absorb UVB and, increasingly effectively, UVA rays. Through a chemical reaction, they then convert UV light into fluorescence or release it in the form of heat.
Does "total sunblock" really exist?
Regardless of the SPF and its composition, no sun protection formula can block 100% of UV rays and therefore cannot claim to provide complete protection from UVA and UVB rays. As a result, claims of "total protection" or "full screen" should not be made. In fact, these inscriptions are now strictly prohibited on the labelling of all UV protection products sold within the European Union.
Indeed, in September 2006, the European Commission adopted this recommendation and grouped all Sun Protection Factors (SPFs) above 50 (60, 70, 80 or even 100) into a single index of 50+. This measure was also taken to protect consumers from misconceptions about this topic, particularly the erroneous belief that unlimited exposure is possible with an SPF 100 applied only in the morning.
Source
Recommendation from the Commission dated 22nd September 2006 pertaining to sun protection products and the manufacturers' claims about their effectiveness. Official Journal of the European Union (2006).
