Sunscreen, often referred to as sunblock or sun cream, is a topical product designed to protect
the skin from the sun's harmful ultraviolet (UV) radiation. Regular and proper use of
sunscreen is a crucial component of a comprehensive sun protection strategy.
How Sunscreen Works
There are two main types of sunscreen, which work in different ways to protect your skin:
1. Mineral (or Physical) Sunscreens: These sunscreens contain active mineral ingredients,
primarily zinc oxide and/or titanium dioxide. They sit on the surface of the skin and act as a
physical barrier, reflecting and scattering UV rays away from the skin like a shield.
o Pros: They are generally considered gentler on the skin, less likely to cause irritation, and
effective immediately upon application.
o Cons: They can sometimes leave a white or chalky cast on the skin, especially on darker skin
tones.
2. Chemical Sunscreens: These sunscreens use organic compounds like oxybenzone,
avobenzone, octinoxate, and octisalate. They are absorbed into the skin, where they absorb
UV radiation and convert it into heat, which is then released from the skin.
o Pros: They are typically more lightweight, easier to rub in, and less likely to leave a white
cast.
o Cons: They may cause skin irritation in some people, and they need about 15-30 minutes to
become effective after application.
Key Terms to Understand
UV Rays: The sun emits two types of harmful UV rays that reach the Earth's surface:
o UVA rays: These rays penetrate deep into the skin, contributing to premature aging,
wrinkles, and long-term skin damage.
o UVB rays: These rays are the primary cause of sunburn and are a major factor in the
development of skin cancer.
Broad-Spectrum Protection: This is a key term to look for on a sunscreen label. It means
the product protects the skin from both UVA and UVB rays.
SPF (Sun Protection Factor): The SPF rating measures how well a sunscreen protects
against UVB rays.
o SPF 15 blocks about 93% of UVB rays.
o SPF 30 blocks about 97% of UVB rays.
o SPF 50 blocks about 98% of UVB rays.
o No sunscreen can block 100% of UV rays. The higher the SPF, the greater the protection, but
the difference between high numbers (e.g., SPF 50 vs. SPF 100) is minimal.
Benefits of Using Sunscreen
Regular use of sunscreen provides numerous benefits for skin health and overall well-being:
Reduces the Risk of Skin Cancer: This is the most critical benefit. By protecting the skin
from UV radiation, sunscreen significantly lowers the risk of developing various types of skin
cancer, including melanoma.
Prevents Premature Aging: Sun damage is the leading cause of wrinkles, fine lines, and age
spots. Sunscreen helps to preserve the skin's collagen and elasticity, keeping it looking
youthful.
Protects from Sunburn: Sunscreen acts as a barrier, preventing the painful redness and
peeling associated with sunburn.
Prevents Hyperpigmentation: It helps to prevent and reduce the appearance of dark spots,
discoloration, and uneven skin tone caused by sun exposure.
How to Choose and Use Sunscreen
1. Choose a Broad-Spectrum Sunscreen: Ensure the label explicitly states "broad-spectrum"
to protect against both UVA and UVB rays.
2. Opt for SPF 30 or Higher: Dermatologists recommend using a sunscreen with an SPF of at
least 30 for daily use. For extended outdoor activities, an SPF of 50 or higher is
recommended.
3. Apply Generously: Most people don't use enough sunscreen. A general rule of thumb is to
use a shot glass-sized amount (about one ounce) to cover all exposed skin.
4. Reapply Frequently: Sunscreen's effectiveness wears off over time. You should reapply it at
least every two hours, or more often after swimming or sweating.
5. Wear It Year-Round: UV rays are present even on cloudy or cool days. Make sunscreen a
part of your daily routine, regardless of the weather or season.
