Summer is here! Finally! And this weekend will be nice and long thanks to Canada Day. So to prep for all those days spent outdoors at the cottage or in the city on a patio, I’ve asked Dr. Sarah Gora, PhD, Scientific and Medical Relations Leader of Vichy Canada to answer all of my burning (ha) questions on sunscreen–from wearing it indoors, to the mysterious UVA rays, and how else we can protect ourselves against the sun.
Remember: Sunscreen is proven to fight skin aging–so unless you want to look like an old leather handbag by the age of 40, lather up and wear a hat!
Thanks again to Vichy and Dr. Gora for taking the time to respond to my questions.
What is the difference between chemical and physical sunscreen? Which ones should we use?
Sunscreen ingredients can be classified in two categories: organic (chemical) or physical. Organic filters have the ability to absorb the different UV rays, whereas physical filters, like titanium dioxide or zinc oxide, work by reflecting the UV rays, with a less extend on UVA compared to some organic filters. So it is not necessary to choose one of the two but you can use a combination of both filter types that ensures a protection against UVA & UVB and adapted to sensitive skin, if you need so.
How often do we really need to reapply?
One should apply sunscreen 20 minutes prior to going outside to ensure the sunscreen has sufficient time to absorb into the skin and offer 100% protection. As a general rule, you should re-apply every 2 hours and of course, after being in the water or heavy heat/sweating.
Some people don’t think sunscreen is necessary on rainy or overcast days or in the colder months. Can you bust this myth?
Temperature is definitely not a good indicator about potential damage of UV rays exposure. Even if they are partly filtered, UV rays are not absorbed by clouds and neither rain (high cloud cover only stops the penetration of 5-10% of UV). Furthermore they are reflected by water and snow and that increases your exposure. It is good to remember that UVA (95% of UV rays), are present throughout the year contrary to UVB which is stronger in summer.
How much sunscreen should we be using per application?
You should apply a quantity enough to cover the uncovered area. The recommended quantity is about 30 ml for an adult’s body so the equivalent of a golf ball. For the new Capital Soleil InvisibleMist we recommend spraying the arms for 3 seconds, the legs for 4 seconds and the front and back for 4 seconds, then rub in with circular motions.
What is the minimum SPF everyone should be wearing?
The choice of the SPF should be oriented by the phototype (the skin tolerance to UV radiation and its ability to synthesis melanin) and sun condition. It is recommended to wear a borad-spectrum sunscreen (UVA & UVB protection) with a minimum SPF of 30, even for dark skin tone. For example people with very fair skin should use SPF 50 and more.
Why should we avoid alcohol in spray sunscreens?
A high content of alcohol in a sunscreen can leave the skin feeling dry (or even cause a stinging sensation) which can irritate people with sensitive skin. It is also a personal preference, many people choose to only use products that are alcohol-free. And not to mention that accidents have happened in the past when an alcohol based sunscreen was applied too close to an open flame!
What is the importance of using a sunscreen that protects against both UVA and UVB rays?
UVAs are the more abundant rays received and penetrate deeply through the skin. They are responsible for immediate pigmentation, skin ageing and skin cancer. Whereas UVBs cause sunburn, epidermal thickening and skin cancers.
I’ve read that sunscreen is just one way of protecting ourselves. What else can we do?
Sunscreen is a good way to be protected from UV rays but it is not enough and should be completed with other protection like clothing, wear factor 3 sunglasses and a wide-brimmed hat. We recommend to avoid exposure during the peak hours, i.e. between 11 am and 4 pm, when UV radiation–particularly UVB–is at its highest.
Do we need to wear sunscreen in the shade or in a car?
You don’t need to wear a sunscreen when indoors but shade made by an umbrella is not good enough to block UV rays. But you should be protected if you are exposed through a window like in your car. As contrary to UVB which produces an immediate reaction (sunburn), UVA pass through glass and penetrate into the skin deeply to cause silent and invisible damage day after day.
What are the long-term effects of sunburns?
Sunburns are the visible sign of over-exposure, they are mainly causes by UVB rays. But even before sun burn, unprotected exposure to UV ray affect skin’s support fibres and rise the synthesis of oxidising substances. The erythema or sun burn manifests an inflammatory reaction and may also cause DNA damage. These damages build up and can cause in long-term photo-aging and skin cancer in epidermal and dermal cells.
How often should we replace our sunscreen? Can I still use my bottle from last year?
Sun protection products generally have a 3 year shelf-life, unopened! A product that you open this year should never be used next year, since the temperature variations to which it is subjected after opening can affect the stability of the filters it contains.
Does a higher SPF sunscreen always protect your skin better?
A high SPF index represents a higher level of protection but it shouldn’t be the reason to expose longer! And it is important to remember that SPF is only an UVB factor and do not represent the UVA protection. It is therefore important to choose a SPF (min 30) accordingly to the photype/sun condition AND to have a UVA protection.
Those who don’t have fairer complexions often argue that they don’t burn, so they have no need for sunscreen. Is that true?
Dark skin tone has a natural sun protection related to their high concentration in melanin but this is not sufficient. Sun exposure can cause skin lesions of varying severity, ranging from premature aging of the skin, sunburn, or melanoma (skin cancer). Dark skin has a lower risk to develop a melanoma than a fair skin but excessive exposure to the sun damages all skin phototype.