Saturday, January 11, 2014

Safety of UV-light cured nail polishes (gel, shellac)

There was a study recently published by dermatologists at the University of Utah, which measures nail lamp UVA exposure amounts over a year and the significance.  Other than this study, there has been only one other regarding UVA nail lamp exposure, which did not provide the same helpful information.

In this new study, the doctors estimated the amount of time of UV exposure based on the average time needed under the lamp per full set of nails.  They assumed the nail client has their nails done every three weeks for a year.

International experts recommend limiting your UVA exposure to no more than 30Joules/m2 for 8 hours to avoid significant cellular DNA damage.  They calculated that the total cumulative dose of UVA exposure per year in the average gel/shellac nail polish client was 285-386 Joules/m2 which is about ten times the max. limit for 8 hours.

To translate this to a year of gel /shellac UVA-cured polish, one could say each manicure involves four minutes of UVA, and if done every 3 wks, tranlates to 17 nail treatments.    17 treatments at four minutes duration each of UVA, is about 68 minutes or just over an hour of UVA per year.  Phew, I hope that wasn't too confusing.  So what does over an hour of UVA mean as far as hazards?  Well...during that one hour the total dose is 285-386 Joules, but we all know that the one hour of exposure is divided into 17 plus treatments, so it's not one straight hour of exposure.

Bottom line is this study implies that the UVA exposure from a nail lamp COULD BE hazardous over time but it seems we need more studies to clarify if the cumulative dose over a year at 285-386 Joules is really significant when the exposure is in 4-5 minute increments.

The authors of the study I am referring to do advise that if you use a UVA nail lamp, that you put on sunblock a half hour before your treatment.  I would agree that until further study, that is probably a good idea.  Those gloves that have the fingers cutout are pretty good but they don't protect the skin around the nails, so are inadequate.  Try the gloves and then applying sunblock on the remaining exposed skin.

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