Sunscreens

What is Sunscreens for?

Excessive exposure to sunlight causes sunburn, premature aging, wrinkling and brown pigmentation. It also increases the risk of skin cancer. In some people, sunlight may induce skin rashes or worsen an existing skin condition. Although your skin has its own natural defences, it is not enough to prevent the damage caused by ultraviolet radiation.

The so-called 'healthy tan' is actually a response to sun damage. The skin starts to become darker and the outer layers become thicker in an effort to provide a better barrier against the sunrays. However, the harmful rays are still able to penetrate this natural barrier. Additional protection is essential to prevent damage into the deeper layers of your skin.

Sunscreens are creams, lotions, or sprays that protect the skin from the damaging effects of ultraviolet radiation of the sun by providing a chemical or physical barrier to it.

Chemical sunscreens (organic sunscreens) absorb ultraviolet radiation, preventing it from reaching the deeper layers of the skin. Examples of some common active ingredients are:

• Octyl triazone (ethylhexyl triazone)
• Homosalate  
• Octocrylene
• Oxybenzone (benzophenone-3)
• Avobenzone (butyl methoxydibenzoylmethane)
• Octinoxate (ethylhexyl methoxycinnamate)
• Octisalate (ethylhexyl salicylate)

Physical sunscreens (mineral or inorganic sunscreens) contain zinc oxide and titanium dioxide. Physical sunscreens, especially those containing micronised or nanosized zinc oxide and titanium dioxide primarily function by absorbing ultraviolet radiation and minimally by scattering and reflecting light. Physical sunscreens are recommended for individuals with sensitive skin. 

Sun Protection Factor (SPF) is an index to indicate the degree of protection from ultraviolet B (UVB), the type of ultraviolet radiation that is more likely to cause sunburn. The higher the SPF, the longer the duration of the protection. 

Ultraviolet A (UVA) plays a major role in skin aging and wrinkling. UVA protection can be indicated in several ways, including a circle around the letters "UVA", PA+++, or a 4-star UVA protection, on the packaging of the sunscreen.

A broad-spectrum (protects against UVA and UVB rays) and water-resistant sunscreen with at least SPF 30 is recommended.

Use sunscreen with SPF of 30 or higher during high altitude activities such as skiing and mountain climbing. At high altitudes, the air is thinner to absorb the sunrays, so exposure to the sunrays is higher and the risk of your skin burning is higher.

How should I take or use Sunscreens?

• Dry your skin well before applying the sunscreen.
• Apply the sunscreen to all sun-exposed areas 15 minutes before going into the sun.
• Most adults need an average of 1 ounce of sunscreen (the amount to fill a shot glass) to fully cover all sun-exposed areas. Use at least 1 teaspoon of sunscreen on your face.
• Apply the sunscreen generously and evenly over the exposed areas of the whole body, including behind your ears, back of your neck and tops of your feet.
• Wait for the sunscreen to dry before putting on your clothes or makeup.
• Re-apply sunscreen every two hours, and immediately after swimming or sweating.
• Use sunscreen even on cloudy or overcast days. The sunrays are as damaging to your skin on hazy days as they are on sunny days.

What precautions should I take when taking or using Sunscreens?

• Inform your healthcare professional if you are allergic to sunscreens or any of its ingredients.
• If you have oily or acne-prone skin, use non-comedogenic (does not clog pores) sunscreens and avoid greasy formulations of sunscreens.  
• Other ways to maximise sun protection include:
  • Avoiding the sun when it is strongest between 11am to 3pm.
  • Wearing protective clothes under the hot sun. Even if you are under the shade on the beach, sunrays can be reflected off the sand and cause a burn on your skin.

What are some common side effects of Sunscreens?

• Temporary stinging sensation

What are some rare but serious side effects that I need to seek medical advice immediately?

• Symptoms of a severe allergic reaction which include one or more of the following:
  • Swollen face/eyes/lips/tongue
  • Difficulty in breathing
  • Itchy skin rashes over your whole body
• Skin redness or irritation such as burning, itching
• Localised skin rash or swelling
• Pimples (acne)
• Pain in hairy areas
• Pus in the hair follicles

If you experience any of these symptoms, you should stop your sunscreen and see your healthcare professional immediately.

How should I store Sunscreens?

Store in a cool and dry place, away from direct sunlight. Keep this away from young children.

How do I throw away Sunscreens safely?

Pack the sunscreen into a black trash bag and seal it tightly before throwing into the rubbish chute or bin.