Sunscreen: What You Need to Know

Using sunscreen is crucial to safeguard your skin from the harmful rays of the sun. The Canadian Dermatology Association supports the use of sunscreen as an effective and safe means of sun protection. Scientific research has provided strong evidence of the damaging effects of UV exposure on the skin, while any potential negative effects of sunscreen on your health are still uncertain and unsubstantiated. Therefore, it is important to understand the significance of sunscreen in maintaining the health and beauty of your skin.

What is sunscreen?

Sunscreen is a specially formulated product designed to protect our skin from the harmful effects of ultraviolet (UV) radiation. UV radiation, which comes from the sun, can cause damage to our skin cells and DNA. Prolonged exposure to UV radiation can lead to sunburn, premature aging, and an increased risk of skin cancer.

What are the ingredients in sunscreen?

The main ingredients in sunscreen can be divided into two categories: organic compounds and inorganic compounds.

• Organic compounds are derived from plants or made synthetically and are responsible for absorbing UV radiation before it can damage your skin. These may also be called chemical sunscreens. 
• Inorganic compounds scatter and block UV radiation from penetrating the skin, creating a protective barrier on the skin. These may also be called physical or mineral sunscreens.

Some sunscreens may also include other chemicals, such as antioxidants. These antioxidants help reduce the damage caused by UV radiation and provide additional benefits for the skin.

Is sunscreen damaging to aquatic life?

If you are concerned about the environmental impact of sunscreen on coral reefs, it is important to note that the safety of specific ingredients is still being studied and any direct correlation between sunscreen ingredients and damage to coral reefs is inconclusive. To minimize potential harm, you may consider wearing protective clothing in water, like high-necked, long-sleeve rash guards, which can reduce the amount of sunscreen needed and limit any potential impacts on the environment.

Are there toxic ingredients in sunscreen?

In Canada, all sunscreens have passed a review by Health Canada and are given a drug identification number (DIN), so they are safe to use. There is no evidence supporting the idea that sunscreen causes cancer and common misconceptions that oxybenzone and retinyl palmitate (two common ingredients in sunscreen) are bad for your health has not been proven. It is important to remember that UV radiation is a scientifically proven carcinogen and has been officially classified as carcinogenic to humans by the WHO International Agency for Research on Cancer. Regular and effective sunscreen use is an essential component of protecting yourself against UV radiation.

How long does sunscreen last?

The shelf life of sunscreen depends on various factors, including its formulation, storage conditions, and the expiration date. In general, most sunscreens remain effective for 2-3 years. However, it is essential to check the expiration date on the sunscreen packaging to ensure its effectiveness.

Sunscreen can degrade over time, especially if exposed to high temperatures for extended periods. To maintain its potency, it is recommended to store sunscreen in cool and dry places, away from extreme temperatures. Avoid leaving sunscreen in hot environments like cars, as the heat can diminish its effectiveness.

By following proper storage guidelines and regularly checking the expiration date, you can ensure that your sunscreen provides the necessary protection when you need it.

What types of sunscreens are available?

Sunscreens come in various types, each offering unique features to safeguard our skin from the harmful effects of the sun.

Broad Spectrum Sunscreen: The term “broad spectrum” indicates that a sunscreen offers protection against both UVA (ultraviolet A) and UVB (ultraviolet B) rays. UVA rays penetrate the skin deeply and contribute to skin aging, while UVB rays are the primary cause of sunburn. Both types of rays play a role in the development of skin cancer. It is important to choose a sunscreen that effectively shields you from both UVA and UVB rays.

Water-Resistant Sunscreen: Water-resistant sunscreens are designed to remain effective for a certain period of time when exposed to water or heavy perspiration. While no sunscreen is completely “waterproof” or “sweatproof,” these products specify whether they remain effective for 40 or 80 minutes. It is still necessary to reapply sunscreen every 2 hours, but water-resistant sunscreens are great for activities like swimming or when you expect to sweat a lot. They are formulated to stay on your skin for the specified time while in contact with water, providing continued protection.

Aerosol Sunscreen: Aerosol sunscreen comes in a spray canister, allowing for easy application onto the skin and provides a convenient way to apply sunscreen on hard-to-reach areas. However, one concern with aerosol sunscreen is that it does not always provide sufficient coverage. To address this, it is recommended to apply aerosol sunscreen in an area with minimal wind interference, use just for touch-ups, or hold the spray close to your skin for adequate coverage, and follow up by gently rubbing the sunscreen into your skin. This ensures even distribution and enhances absorption, maximizing the effectiveness of the aerosol sunscreen.

What SPF level of sunscreen is recommended?

SPF, which stands for Sun Protection Factor, is a measurement of how well a sunscreen can filter out UVB rays. It is important to use sunscreen with an appropriate SPF to protect our skin from sunburn and other harmful effects of the sun.

For optimal sun protection, it is recommended to use a broad-spectrum sunscreen with an SPF of 50+ or higher. This means that the sunscreen can provide a high level of protection against UVB rays, which are responsible for sunburn as well as protection against UVA rays, which can contribute to skin damage and aging.

It is essential to reapply sunscreen every 2 hours, as the effectiveness of sunscreens gradually decreases over time. Even if a sunscreen has a high SPF, it does not mean that it will provide protection for a longer period or allow us to stay in the sun for a longer time without reapplying.

To give you an idea of the level of protection provided by different SPF levels, here’s a breakdown of the percentage of UVB rays filtered out:

To ensure adequate sun protection, it is crucial to choose a sunscreen with a high SPF (30 or more) and reapply it regularly, especially after swimming or sweating. Remember that higher SPF offers greater protection against UVB rays.

How do I apply sunscreen correctly?

Proper application is important to protect your skin from the harmful effects of UV radiation. Here are some important points to keep in mind:

Sunscreen safety:

• Check for Skin Sensitivity: Before using a new sunscreen, perform a patch test on a small area of skin to ensure you don’t have any adverse reactions or sensitivity. If you have a history of skin allergies or sensitivities, consult a dermatologist for guidance.
• Sunscreen and Children: When applying sunscreen on children, use products specifically formulated for them and consult with a pediatrician or dermatologist to ensure safe and effective application for their delicate skin.
• What to Look for: Look for sunscreens that are supported by the Canadian Dermatology Association. When you see a Recognized Sun Protection logo on products, you can trust that they have broad spectrum protection, are SPF 30 or higher, have low potential for irritation, are minimally perfumed or non-perfumed, and are non-comedogenic (won’t block your pores).

Sunscreen application tips:

• Apply Generously: Use enough sunscreen to cover all exposed areas of your skin. As a general guide, aim for about one ounce (equivalent to a shot glass full) of sunscreen to cover your entire body.
• Reapply Regularly: Sunscreen should be applied 15 minutes before going outside and reapplied every two hours or more frequently if you are swimming, sweating heavily, or toweling off. Even if a sunscreen is labeled as water-resistant, reapplication after water exposure, and every two hours, is necessary to maintain optimal protection.
• Don’t Forget Vulnerable Areas: Pay special attention to commonly overlooked areas like the tops of your feet, ears, back of the neck, and lips. These areas are prone to sunburn and need adequate protection.
• Apply SPF Regardless of the Weather: Regardless of how cloudy, gloomy, or overcast it seems, it is still essential to wear SPF every day. UVA and UVB rays can penetrate haze, fog and clouds and easily reflect off water, cement, sand and snow.

• Combine Sunscreen with Other Protective Measures: Remember that sunscreen is just one part of a comprehensive sun protection strategy. Seek shade during peak sun hours, wear protective clothing such as hats and sunglasses, and try to limit direct sun exposure whenever possible.

Quote from Dr. Geeta Yadav MD, MHS, FRCPC 

As dermatologists, the number one ingredient we recommend to all of our patients is sunscreen. The truth is that the sun’s rays are incredibly damaging. By exposing yourself to UV radiation on a daily basis, you are putting the health and beauty of your skin at risk. It’s incredible that there’s a product you can buy at the drugstore that could save your life: By simply applying any SPF 30 or higher on a daily basis, you can dramatically reduce your chances of developing skin cancer — and knowing that melanoma is one of the deadliest forms of cancer, why would you take the risk?