ASK DR. DESAI ~ Tips for buying green personal care products - Sunscreen
Sunscreens have a Sun Protection Factor (SPF) designation, which provides consumers with an idea of the degree to which the Sun’s radiation is being mitigated. For example, SPF 15 means means that 1/15th of the solar radiation will reach the skin, assuming the sunscreen is applied evenly at a thick dosage of 2 milligrams per square centimeter (mg/cm2). Looking at it another way, if a person experiences sunburn in 10 minutes of sun exposure without sunscreen, use of SPF 15 will provide 150 minutes of sun protection before they experience sunburn.
However, SPF is an imperfect measure of skin damage, at best, since invisible damage and skin aging are also caused by ultraviolet type A (UVA) which does not primarily cause skin reddening or pain. Ultraviolet A (UVA) is the longer wave UV ray that causes lasting skin damage, skin aging, and may cause skin cancer. Ultraviolet B (UVB) is the shorter wave UV ray that causes sunburns, skin damage, and may cause skin cancer.
The ingredients that provide this protection in sunscreens are usually one of two kinds—chemical or mineral— though some products may use both. Chemical ingredients work by undergoing a reaction and absorbing the UV light. Minerals work by physically blocking the sunlight via reflection or scattering and may also absorb sunlight.
Since some chemical ingredients are unstable and require stabilizers in the formulation to promote their shelf life. I have highlighted 3 ingredients below to watch out for.
What are Oxybenzone or Octinoxate or Homosalate?These are chemical UV filters commonly found in sunscreens
What is the purpose of Oxybenzone or Octinoxate or Homosalate in personal care products?These are chemicals that not only function as chemical filters that block UV radiation but also as penetration enhancers, which promotes other chemicals penetrate the skin better and assist with UV protection.
What health risks are associated with Oxybenzone or Octinoxate or Homosalate?The health risks posed by these ingredients range from absorption through the skin, endocrine disrupting (or hormonal mimicking), allergies, or reproductive toxicity in animals.
So the next time you buy sunscreens try and choose formulas that are oxybenzone or octinoxate or homosalate free. mineral based sunscreens that contain Zinc oxide or titanium dioxide or the chemical Avobenzone are generally less hazardous. You may want to look up Sun Facts and other information on the Skin Cancer Foundation’s website at Skincancer.org.
Stay tuned for the next monthly installation of this series to learn about what else you need to be on the lookout for and avoid.
Dr. Vinay Desai is a naturalist and a pharmaceutical scientist with a Ph.D. in Pharmaceutical Sciences. Through community awareness programs, Dr. Desai helps educate people in the sustainable practices of using solar power and green personal care products.