The summer has come here in the Northern Hemisphere and every Dane is sunbathing half naked like there’s no tomorrow – this pale sample included (but following the rules of proper sun protection, obviously).
Regardless the joys of the sun beaming down on us, we must protect our skin to prevent chronic sun damage such as wrinkles, freckles, brown spots, mottled pigmentations and skin cancers.
However, the amount of sunscreen, when and how often you apply it during the day is crucial if you want sufficient sun protection.
In fact, behavioural studies show that people often apply far less than the recommended amount of sunscreen, resulting in a useless sun protection, and that people in general don’t know basic facts about sun protection1,2 (scribbles note to self to write a SPF guide blog post).
It’s a very well studied dermatological subject and we know that the thickness of the sunscreen layer applied directly correlates with the sun protection and people often achieve only 20-50% protection of the SPF (sun protection factor) labelled on the bottle3. That could explain all the sun burns that people get each year despite the fact that they’ve been using sunscreen – oops. But despair no more, researchers has come up with ‘the teaspoon rule’ – a teaspoon of sunscreen that is – to help us apply the right amount.
- One teaspoon in total for your face, neck and ears
- One teaspoon per arm
- One teaspoon per leg
- One teaspoon for the front of your torso
- One teaspoon for your back
If you’re going skinny dipping or sunbathing in your birthday suit use one handful (circa 40 millilitres) for the whole body. For children “one handful for the whole body” applies too, just the child’s own handful, and use half a teaspoon for the child’s face, neck and ears4. More is more here, we wouldn’t want a sunburned child!
And this is just half a teaspoon of sunscreen – keep pumping
When and how often?
Many recommendations and “good advices” exist, when it comes to when and how often you should apply sunscreen – some more evidence based than others. A recent study concludes following thumb rule: To achieve the full protective effect of your sunscreen, it should be applied to the exposed skin 30 minutes before going out in the sun and reapplied 30 minutes after the sunbathing has begun. AND reapplied if you’ve been sweating excessively, e.g. exercising (who does that when it’s warm and sunny?), bathing or toweling4.
A Good Tip!
I’ve practiced the teaspoon rule this summer and I was truly surprised how much sunscreen there can be on a teaspoon – it’s certainly a lot more than I used to apply. At first I slapped all the sunscreen on at once, more than my skin could absorb, resulting in a slippery face and sweaty feeling. But I’ve worked my way around it and my trick to avoid a SPF-sweating face is to apply it in two or three layers, so my skin has time to absorb the product.
The teaspoon rule – the actual amount of a teaspoon sunscreen
The 3 golden rules of sun protection
Although the most important factor in sun protection is to apply the right amount of sunscreen to begin with3,5, sunscreen shouldn’t stand alone.
Alongside with your SPF-routine in the morning and reapplication during the day, you should stay in the shade when possible (just think of the old tin foil-using wrinkled tan lady in There’s Something About Mary – we would want that! Yes I’m sun tanning shaming 😛 )
And lastly you should wear a sun hat – we’re talking Pretty Woman, Julia Roberts at the derby sized hat, (what’s up with all the movie references?) leaving your face, neck and partly shoulders in the shade6. In fact, wearing sun protective clothes (i.e. clothes!) should be preferred to sunscreens5.
In conclusion, if you want to protect your skin correctly from sun damage (wrinkles, pigmentations, skin cancer) follow these golden rules
1) Sunscreen + reapplication
2) Seek the shade
3) Sun hat (and sun protective clothes)
Take care in the sun!
1. Behrens Cl & Darsø L: Danskernes solvaner i den danske sommer 2013 – en kortlægning. Kræftens Bekæmpelse og Trygfonden smba (TryghedsGruppen smba), 2014.
2. Wickenheiser M et al., Sun Protection Preferences and Behaviors among Young Adult Males during Maximum Ultraviolet Radiation Exposure Activities, Int J Environ Res Public Health. 2013 Aug; 10(8): 3203–3216. 10.3390/ijerph10083203
3. Stokes R.P., Diffey B.L. How well are sunscreen users protected? Photodermatol. Photoimmunol. Photomed. 1997;13:186–188. 10.1001/archdermatol.2007.45
4. Diffey B (2001). “When should sunscreen be reapplied?”. J Am Acad Dermatol. 45(6): 882–5., 10.1067/mjd.2001.117385