See what Doug Schoon has to say about this very important question. Why you might ask? Because when the gel is not properly cured (even if it looks like it is) not only is service breakdown a possible problem, when the manicurist files the gel to take it off (which many do in lieu of soaking) the now uncured product is going to get all up in your face & right through the manicurist "doctors mask" that she is wearing that only stops germs & does very little to stop dust particles.
Here is Mr. Schoon's answer -
"I can’t tell you everything you need to know to ensure a product is properly cured in a short text message. There are no simple tests and no simple answers. These are professional products and need to be used by someone who is properly trained. You can learn more about this important topic by reading my books, and/or watching my Internet video series by the same name, www.FacetoFacewithDougSchoon.com. In short, if you use the correct nail lamp (the one(s) specified by the UV gel manufacturer), follow directions and don’t make up your own systems by mixing products that aren’t intended to be used together, this can help ensure you are properly curing. Otherwise, you are rolling the dice and hoping for a proper cure. I don’t recommend rolling the dice, that’s why I write these books and provide these videos. They will help you ensure you are working safely and providing your clients with safe and effective services."
Doug's book, "Face to Face with Doug Schoon Vol 1 is currently available. Customers should read this very important book too. Don't rely on your manicurist! Vol 2 will be available shortly. While Mr. Schoon & I differ on the amount of UVA radiation being emitted from the lamps & being harmful to one's skin, Mr. Schoon has stated the lamps can cause premature aging of the skin...which sounds like a very good reason to shield one's skin during every gel service! Just saying....