Protection from UVA and UVB rays is an important aspect when it comes to choosing a sunscreen. Here is some useful information about sun protection against UVA and UVB rays:

  1. UVA Rays: UVA rays are longer wavelength ultraviolet rays and can penetrate deeper layers of the skin. They are associated with premature skin aging, wrinkles and weakened skin's immune system. They can also contribute to the development of skin cancer. It is important to use a sunscreen that offers good protection against UVA rays.

  2. UVB rays: UVB rays are shorter wavelength ultraviolet rays and can burn the surface of the skin. They are the leading cause of sunburn and are strongly related to the development of skin cancer. Choosing a sunscreen with good UVB protection is essential to prevent skin damage.

  3. Sun Protection Factor (SPF): The sun protection index (SPF) is a number that indicates the level of protection against UVB rays offered by the sunscreen. For example, a sunscreen with SPF 30 means it will take 30 times longer to burn than if the skin is unprotected. However, the SPF does not indicate protection from UVA rays. It is important to choose a sunscreen that offers broad spectrum protection, i.e. against both types of rays.

  4. Key Ingredients: Your sunscreen should contain ingredients that offer UVA and UVB protection. Some common ingredients include zinc oxide and titanium dioxide, which are known as physical filters and offer broad spectrum protection. Other ingredients such as avobenzone, ecamsule and salicylates are known as chemical filters and also offer good protection from UVA and UVB rays.

  5. Reapplying: It's important to remember to reapply your sunscreen every two hours or after swimming or strenuous exercise, even if your sunscreen is waterproof. This helps maintain effective protection against the sun's rays.

In conclusion, to protect the skin from damage caused by UVA and UVB rays, it is advisable to use a broad-spectrum sunscreen with a high SPF and reapply it regularly.