Sunscreen myths and facts
Sunscreen facts and myths
UVA and UVB both carcinogenic
Sunscreens are of 2 types: physical and chemical
Inorganic physical mineral sunscreens
protects from both UVB and UVA
Includes:
Zinc
Titanium dioxide
Chemical sunscreen :
Should say broad spectrum to protect from both UVA and UVB
SPF gives protection only against UVB
Efficacy :
Is higher spf better
Excessively High SPF Does not Provide Significant Benefit
Very minute benefit over SPF 30
No scientific evidence that indicates using a sunscreen with SPF>50 can protect you better than a sunscreen with SPF of 50
In Europe SPF values greater than 50 declared as SPF 50+
Health Canada has same recommendation
Proper sunscreen application Goal=20 mg/cm2
1oz/30ml of sunscreen to cover an adult =1 golf ball or 1 shot glass
Typical 3 oz and 6 oz bottle should last 3 and 6 applications !!!!!
Only 2 hrs of protection after application regardless of SPF
Sunscreen effective use
What: Broad spectrum, water resistant sunscreen with minimum SPF of 30
Where: all exposed area of body not covered with clothing
How: apply generously and uniformly
When: everyday and year- round 15 minutes before going outdoors, reapply q40-80 min. If swimming or heavy perspiration
What About Infants < 6 mnths
Infants is more susceptible to UVR
-Thinner skin
-Less concentrated with melanin
-immunologically immature
Canadian Paediatric Society
Preferable to avoid sun and use shade and clothing
Sunscreen can be applied to small areas that are not covered e.g. face and back of hands
Avoid the mouth/eye area
To date no evidence for systemic toxicity in young children /infants
Caution
Spray can inhale ,can ignite, application not uniform
Sunscreen decreases the incidence of malignant and premalignant skin conditions including actinic keratosis and squamous cell carcinoma.
Also decrease the occurrence of nevi or mole
Sunscreen doesnot cause Vitamin D deficiency
Only 2 to 5 min incidental exposure to sunlight enough for Vitamin D production
Oxybenzones are present in most chemical sunscreen
The amount applied causes no hormonal disruption
No acute toxicity
Physical sunscreens:
Nanoparticles zinc oxide and titanium oxide
Small particles penetration of epidermis
Not cytotoxic and not significant penetration
Allergic contact dermatitis to sunscreen less than 1%
Oxybenzone most common
Mostly irritant reaction
If reaction occurs to sunscreen :
Try different sunscreen
Use physical sunscreen
Can do patch test to confirm any allergic reaction
Avoid sun between 11 to 3 pm as UVB
strongest
If shadow smaller than you than higher radiation are reaching the earth so you need to exercise caution
Also remember that sand,snow and water reflects ultraviolet radiation
It is important to wear protective clothing, sunglasses and wide brim hat.