Skin health and beauty science has been driven by innovative ingredients and new formulation technologies and, in a large part, by the tremendous advances in the knowledge of skin physiology in the last 20 years. The increased knowledge about UV (Ultraviolet) induced skin damage and awareness has led to the development of new UV filters with improved efficacy and safety. This article is intended to provide education regarding types of sunscreen and their proper use as well as some knowledge of the damage caused by UV rays.
According to ace dermatologists and Cosmetologists, sunlight is composed of 66% of infra-red light (it emits heat), 32% visible light (the light that allows us to see different colors) and 2% ultraviolet light (UVL). The UVL is subdivided into ultraviolet A (UVA wavelength 320-400nm), ultraviolet B (UVB) which is of a shorter wavelength (290-320nm) and UVC (260-290nm), UVB is responsible for sunburns, delayed tanning and DNA mutations leading to skin cancers while UVA is responsible for wrinkling, immediate tanning, and sunspots. UVB penetration is limited while UVA even penetrates through window glass hence exposure is possible while driving a car or staying indoors.
As a preventive measure, dermatologists recommend the use of sunscreen every day. The ideal sunscreen should have a high SPF (Sun Protection Factor) rating, be well tolerated, cosmetically pleasant, non-toxic, equally effective against UVA and UVB, photostable, water-resistant and inexpensive. Unfortunately, no single such sunscreen currently exists. Sunscreens are arbitrarily classified into UV absorbing (chemical) which absorbs specific wavelength either A or B and UV blocking (physical) sunscreens. The SPF indicates the degree of protection the sunscreen offers against UVB mainly. Generally, an SPF of 30 or more is advised. PPD method is used to access protection against UVA and it should be more than 4. The efficacy of a product is related not only to its SPF but also to its substantivity. Substantivity is the ability of a sunscreen to remain effective under the stress of prolonged exercise, sweating and swimming. Sweat-resistant, water resistant and waterproof sunscreens protect up to 30, 40 and 80 minutes of continuous water exposure respectively.
Try to stay indoors during periods of peak UV exposures (11 am to 3 pm). Apply the sun care product 20-30 minutes before moving outdoors, repeat application should be necessary after every 2 hours. 50% to 80% of the rays break through the cloud. Hence, even on a cloudy day, sun care products must be applied regularly. Most people do not apply enough sunscreen to achieve adequate protection. The teaspoon rule of applying sunscreen can be followed. Apply slightly more than 1/2 teaspoon (~3ml/0 of each arm, to the face and the neck. On each leg, the chest and back, apply slightly more than a teaspoon (~6ml). Using an adequate amount of sunscreen provides greater sun protection than using an inadequate amount of a sunscreen with a higher SPF rating. Foundation makeup products without sunscreen may not offer more than an SPF of 4 via its pigment content. However, most of the cosmetic products that contain sunscreen chemicals offer various SPF levels up to 15-30.
Patients should select a broad-spectrum sunscreen that contains agents that effectively block both UVB and UVA rays with an SPF of 30 or greater. Protect children using a maximum sunscreen without forgetting a hat, t-shirt, and sunglasses. Certain products do not resist water or sand friction. Look for the mention “water and sand resistant” above all “for children” products. Check the texture and opt according to your requirements for a fluid, gel or cream. Prefer sunscreens which spread easily without leaving white marks. Look for the mention “non-comedogenic and hypo-allergenic”.
Moreover, use cover-up garments, garments that cover the arms, legs, and torso, wide-brimmed hats and sunglasses are also recommended for greater UV protection. Cotton fabrics provide superior protection from sunlight and tightly woven fabrics offer better protection than loose weaves.
To summarise hyper pigmentary disorders being a major issue in India, it is very important to emphasize the role of prevention and the use of adapted sun protection behavior and sunscreens with well-balanced filtration systems.