Choosing a sunscreen can be difficult. There are hundreds of sunscreen brands available to choose from. It can be very overwhelming when you decide to purchase one and are faced with a wall full of products. Knowing how to interpret the terminology and understanding the different application forms might help to guide you in the right direction. Here are some tips that I have picked up along the way dealing with my sun sensitivity. I hope that they are helpful for you as well.
Before deciding to introduce a new product into your routine always speak to a health care professional (e.g. doctor, pharmacist) to determine if it is safe for you.
1. Chemical vs. Physical Sunscreens
Chemical sunscreens include ingredients that absorb and/or reflect UV radiation. These ingredients are more likely to cause sensitivity reactions in susceptible individuals.
Physical sunscreens include ingredients that reflect and scatter UV radiation. The most common ingredients are titanium dioxide and zinc oxide. These may worsen acne in susceptible individuals.
2. UVA and UVB protection
It is very important to choose a broad spectrum sunscreen. This means that the ingredients included in the sunscreen protect against both UVA and UVB rays.
UVA rays penetrate the skin and are present throughout the day. They are not blocked by physical barriers such as clouds, windows, and clothing. UVA rays are usually associated with aging.
UVB rays damage the skin causing sunburn and redness. UVB rays are strongest between the hours of 10 am and 4 pm and at higher altitudes.
Both play a role in the development of skin cancer.
3. SPF (aka Sun Protection Factor)
Every sunscreen has a SPF value and it can range from anywhere between 4 to 100.
But what is SPF and what does it represent?
SPF is an indicator of how long it would take for your skin to start to burn. In other words, it mainly tells you about how long the sunscreen will protect against UVB rays. It is calculated by dividing the time it would take to burn with sunscreen by the time it would take to burn without sunscreen.
For example, if it takes you 10 minutes to burn in the sun without sunscreen after applying a sunscreen with and SPF of 30 it would take you 300 minutes to burn.
However, it is important to understand that this would be the case in ideal situations. In reality, sometimes we don’t put on enough sunscreen, we sweat it off, or it gets rubbed off throughout the day.
Choose a sunscreen with a minimum SPF of 30 for sufficient protection.
4. How to apply
It is important to apply enough sunscreen to evenly and thoroughly cover the exposed area. As stated above, many individuals do not apply enough sunscreen for the SPF factor to be effective.
Follow the teaspoon rule for application amount:
- Face and neck = 1 teaspoon
- Arms, shoulders = 2 teaspoons
- Torso = 2.5 teaspoons
- Legs, feet = 2.5 teaspoons
*Amounts may vary depending on body size and shape.
General Tips:
- Cover all skin surfaces exposed to the sun
- Apply 15-30 minutes before sun exposure
- Re-apply every 15 to 30 minutes or after swimming, sweating, etc.
5. Lotions, creams, gels, sprays
All of these are equally effective if used properly.
When using sprays make sure to apply enough to effectively cover the exposed area. Gels may be more suitable for individuals with oily skin who do not want to use greasy lotions and creams.
If you are going to be exposed to water make sure to look for water resistant sunscreens and to reapply after the exposure.
Below are some resources with additional information that may help when choosing a sunscreen.
- https://www.canada.ca/en/health-canada/services/drugs-health-products/public-involvement-consultations/natural-health-products/draft-guidance-document-sunscreen-monograph-consultation-document.html
- https://www.ewg.org/sunscreen/
- https://www.canadianskincancerfoundation.com/