Most of us are aware that the effectiveness or strength of a sunscreen product depends (partly) on its sun protection factor (SPF) value however, what does all the other information on the bottle mean? Lack of proper understanding of these symbols may lead to the selection of an inadequate sunscreen and possibly sunburns.
Firstly, labeling requirements of sunscreen products vary depending on the country it is made and marketed in, so picking up a sunscreen while holidaying abroad can sometimes be confusing. Here are some of the terminologies you may encounter on a sunscreen label and what they mean:
|Sun Protection Factor (SPF)||Measure of protection against UVB. The higher the numerical value, the greater the protection against UVB when used correctly. Always use a broad-spectrum sunscreen with at least SPF 30.
|This UVA logo used in the European union (EU) countries. This symbol indicates that the sunscreen product meets the minimum required UVA protection, which is at least 1/3 that of the labelled SPF and meet the critical wavelength test requirements.|
|The Boots star rating used in the United Kingdom indicates the ratio of UVA rays absorbed by the sunscreen product versus UVB. Higher number of stars indicate better UVA protection. Currently, products are rated ‘no stars’, 3, 4, or 5 stars. Because the star scoring system is based on a ratio; a 3-star rating on an SPF 50 sunscreen is not the same as that afforded by a UVA 3-star sunscreen with SPF 30.
A sunscreen with at least SPF 30 and 4 or 5 UVA Boots star rating would be sufficient for daily use alongside adequate protective clothing.
|UVA-PF||The UVA protection factor (UVA-PF) is measured using a test similar to that conducted for SPF measurement known as Persistent Pigment Darkening (PPD). The UVA protection grades are often labelled as PA followed by ‘+; ++; +++ or ++++’ in Asian countries; or sometimes as PPD followed by a numerical number in some European countries. The more ‘+’ or the higher the numerical value indicates better UVA protection.
||These seals of recommendations are a Skin Cancer Foundation initiative.
Products with ‘Daily Use Seal’ are intended for protection against both UVA and UVB as a result of incidental exposure. Meanwhile the ‘Active Seal’ is for products suited for extended sun exposure due to outdoor recreational activities, and such products would have higher protection against UVA/ UVB as well as water/ sweat resistance.
|Broad-spectrum||Sunscreen products have to exhibit adequate protection against both UVA and UVB in order to qualify as broad spectrum. Sunscreens in the US are required to pass the critical wavelength test to establish adequate protection against UVA. For EU, Australia and New Zealand sunscreen products have to exhibit UVA protection factor of at least 1/3 that of the labelled SPF.
Always select a broad-spectrum sunscreen which protects against both UVA and UVB as both are damaging to the human skin. More info read here.
|Water Resistant (40 mins)
Water Resistant (80 mins)
|This label means that the sunscreen would remain efficacious after water immersion for 40 and 80 minutes respectively.
Sunscreens bearing these labels would be suitable for outdoor activities involving sweating and water immersion.
|The ‘period-after-opening’ symbol indicates the duration of which the product remains effective for usage after its first use when kept under recommended storage conditions. A logo with 12 M would indicate a duration of 12 months, 24 M would indicate 24 months and so forth.|
Last but not least, here is a video on how to properly use your sunscreen.
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- Australian regulatory guidelines for sunscreens. 2016.
- Ngan, V. 2012. Sunscreen Testing and Classification. DermNet NZ.
- Lionetti, N., Rigano,L. 2017. The new sunscreens among formulation strategy, stability issues, changing norms, safety and efficacy evaluations. Cosmetics 4(2):15.
- Moyal, D. How to measure UVA protection afforded by sunscreen products. Expert Rev Dermatol. 2008; 3(3): 307 – 313.
- Ho, T.Y. Sunscreens: Is looking at sun protection factor enough? Hong Kong Dermatology & Venereology Bulletin.
- Pelizzo, M. et. al. In vitro evaluation of sunscreens: An update for the clinicians. 2012. ISRN Dermatol, 2012.