Sun damage is cumulative

If you’re going to be out in the sun, sunblocks or sunscreens can protect your skin. Ultraviolet radiation (both UVA and UVB) from the sun damages skin cells and can cause sunburn, premature aging and even skin cancer. UV radiation releases free radicals that can cause cellular damage at the DNA level.

The UV damage is cumulative. So even if you are not out in the sun a lot, do consider using sunblock regularly. That dash to the car all adds up. In fact it would be a good idea to work it into your daily skin care routine.

Types of sunblocks

Topical sunblocks often combine different ingredients to help stop UV rays from damaging your skin. They can come in creams, gels, spray-ons or wax sticks. There are two categories of sunblock ingredients

  • Physical sunblocks: The physical sunblocks – mainly titanium dioxide or zinc oxide – are minerals that are ground into fine particles.  They sit on the surface of the skin and reflect UV rays away from your skin like little tiny mirrors. These particles also give the whitish sheen on the skin when applied.
  • Chemical  sunblocks:  Chemical sunblock ingredients form a thin protective film that absorbs UV radiation before it penetrates the skin. A chemical reaction converts the UV radiation into less harmful rays. This reduces the harmful potential of the UV radiation.

The SPF factor does not signify which type of sunblock is in the ingredients. What is signifies is how long more it would take for you to reach a controlled sunburnt state if you applied the product.

Many articles out there in the internet will say SPF30 is 97% protection or something like that. There are too many confounding factors to correlate their studies to real life scenarios. What is easily measurable is the protection compared to another placebo area, in terms or time it takes to reach a standardized level of sunburn.

What's important to know as consumers is that sun-protection is more than just sunblocks. And sunscreen or sunblock you buy is never 100%.

Is one type of sunblock superior to the other?

The 2 types of sunblock each have their advantages.

Physical sunblocks generally do not cause irritation or allergies. But they leave a whitish sheen on the face or parts when applied. They are harder to spread evenly and also harder to wash off. Which is good for it's water-resistant property.

The chemical sunblocks are usually clear and easier to apply. But these are more likely to cause irritation and allergic reactions.

Many sunblocks that you find over the counter are a combination of the two types to maximize the benefits of but minimize the downsides. And many broad-spectrum coverage sunblocks deliberately use a combination of ingredients to protect against both UVA and UVB rays.

Sunblocks are safe

When it comes to sunblocks, the benefits far outweigh any potential risk. Studies show that both physical and chemical sunblocks that are available today all appear to be safe.

The association between sun exposure and skin cancer is well established. Studies show that sunscreen can help prevent skin damage, which can lead to skin cancer.

Many patients still have doubts about the necessity or safety of sunblocks.

“I understand their concern. While we know that UV radiation can increase the production of free radicals that lead to cell damage,” Dr David Loh explains that “our bodies have amazing capacity to heal from sun burns and temporary sun damage. But cumulative sun exposure may damage our skin cells irreparably leading to premature aging skin cancer.”

Wearability is an important factor

The biggest danger of using sunblocks use may be the false sense of security it provides. Just because you use sunblock, it doesn’t mean you can’t get sunburned or get skin cancer. Those who use it tend to be in the sun more, and we all tend to under apply sunblocks.

Or perhaps it is uncomfortable to wear sunblock when outdoors exercising. Perhaps it irritates the eyes when sweat runs down the forehead. And sometimes sunblocks leaves too much of a whitish sheen after application. Manufacturers need to be cognizant of all these factors which influence the wearability of the product.

An ideal sunblock or sunscreen, should feel light, be invisible after application, and be sweat and waterproof to a reasonable extent.