“Why Protecting Customers Skin During Gel Services is Essential”
Purpose: To compile information from published studies on the amount of UVA radiation customers are being exposed to during gel manicures, to illuminate the possible damage to the skin and to highlight why the current photobiological standards being used to measure this irradiance are not applicable for the measurement of UVA radiation being emitted from the nail lamps.
The concern of skin cancer risk and premature aging of the skin from UV/LED nail lamps used to cure gel polish has been the subject of controversy. Numerous articles and studies have been published discussing whether the use of nail lamps increase premature aging of the skin. The methodology used to determine the amount of irradiance emitted from the nail lamps in these studies is predicated on using UVB dominant weighting functions which then suppress the presence of the UVA radiation and subsequently, allow for longer curing times to be deemed safe. Even using these outdated methods, the lamps have been determined to emit approximately 40 minutes of equivalent sunlight each gel service and the lamps have been classified as a Risk 2 Category lighting source, the highest risk category of lighting systems allowed to be used by the general public under unsupervised conditions. It has also been determined it takes only 8-14 visits in order for the DNA to be compromised by being exposed to these UV light sources without a photosensitivity present. It is impossible not to conclude significant damage to the skin is occurring.
In 2010, a report commissioned and completed by nail industry insiders, “Do UV Nail Lamps Emit Unsafe Levels of Ultraviolet Light?” was published. The findings concluded each gel manicure service is equal to spending 21 to 37.5 minutes in direct sunlight. They additionally reiterated the importance of protecting the skin if a photosensitivity exists. However, not everyone realizes they have a photosensitivity or that they have been exposed to a photo-sensitizing agent as confirmed by Dr. Chris Adigun, “Sadly, most people have no idea that they have increased UV sensitivity-whether it is due to a medication, supplement, or medical state. They may or may not see the potential damages immediately after an exposure to an UV lamp, but will suffer the consequences from the cumulative exposure at an accelerated rate as compared to an individual without UV sensitivity."
Published in the Journal of Investigative Dermatology in 2012, Dr. Alina Markova and Dr. Martin Weinstock “elected to compare UV nail lamp irradiance with exposure of narrowband UVB (NBUVB) used in phototherapy, in order to provide a perspective with respect to a common and well-known exposure. NBUVB is a commonly used dermatological treatment...”1 Here’s what came out of this study, “One would need over 250 years of weekly UV Nail sessions to experience the same risk exposure as during one NBUVB course.”2
The doctors evaluated these spectral irradiance values by weighting to the SCHPh- (Skin Cancer Utrect Philadelphia – human) to determine the source’s effectiveness. This data, however, relates to the non-melanoma action spectrum, not the melanoma action spectrum that has a more significant UV-A component. If one’s measurements are based on an UVB dominant weighting function, the presence of UVA is suppressed by 3 to 4 orders of magnitude. Because the UV nail lamps are not generating any significant amount of UVB light, applying these weighting functions are underestimating the risk associated with the UVA irradiance. No one seems to notice this discrepancy.
In 2013, Dowdy and Sayre published “Photobiological Safety Evaluation of UV Nail Lamps.” They examined 6 nail lamp systems, three using the traditional fluorescent bulbs to cure and three using the LED bulbs. Using safety standard time-based and spectrally weighted methodologies, they assessed the most powerful nail lamp was more than an order of magnitude less than the most powerful sunlamp. Not unlike the Markova work, the comparison seems out of place since there is virtually no UVB emitted from the nail lamps, whereas the sun lamps emit a substantial amount of UVB. In using the applied weighting functions, the resulting calculations suppress the value of the UVA.
Dowdy and Sayre measured the UV at the relevant distance for hand exposure at 1 cm above where the fingers rest. Even with using the methodology of weighted functions, all the lamps except one were found to be in the Risk 2 category of lighting sources. A Risk 2 category light is the highest risk category allowed to be
used by the general public in unsupervised conditions.
Surprisingly, the doctors published very detailed information relative to the unweighted methods and the results for skin and eye exposure at 20 cm from the devices, but did not publish the unweighted UVA irradiance values at the 1 cm distance for these devices. At 20 cm outside of the lamp, many of the devices were classified as no risk or low risk. Unfortunately, it is this conclusion that is often repeated without the specification that it pertains to the light 20 cm outside of the lamp, giving the impression the exposure inside the lamp is benign.
In 2014, Lyndsay R. Shipp, MD et al. published a research letter “Further Investigation Into the Risk of Skin Cancer Associated With the Use of UV Nail Lamps,” published in JAMA Dermatology. Shipp’s paper presents data measuring the irradiance from 17 devices. Two of the 17 devices ‘measured’ less than 1.3 mW/cm2, but 13 of the 17 (more than 75%) of the devices had a median irradiance higher than 9 mW/cm2. DNA damage that can lead to skin cancer is known to occur around 60 J/cm2.
Simply concluding one would need multiple visits to reach the threshold for potential DNA damage is misleading. Assuming a 10 minute cure, 10 mW/cm2 x 60 sec/minute x 10 minutes = 6 J/cm2, it would only take 10 such visits to reach the threshold for DNA damage. Anyone who regularly gets gel services, which need to be repeated every two weeks, has surpassed this threshold.
The safety standards used to assess the lamps applies highly suppressing weighting functions to the overwhelming UVA emission of these devices. In using UVB dominant weighting functions, the presence of UVA is suppressed significantly. Insofar as the nail lamps are not generating any significant UVB, the studies that apply these weighting functions are underestimating the risk associated with UVA. This additionally allows for longer “acceptable” curing times to be deemed safe. When the presence of a photosensitivity exists, the subsequent damage to our skin is frightening to imagine.
1. Markova A, Weinstock MA. Risk of skin cancer associated with the use of UV nail lamp. J. Invest. Dermatol. 2012; 133: 1097–9.
2. Markova A, Weinstock MA. Risk of skin cancer associated with the use of UV nail lamp. J. Invest. Dermatol. 2012; 133: 1097–9.