Hazards & Dangers - Technically speaking, anything that is applied to the natural nail causes "damage", even nail polish but it is degrees of damage that you need to watch for. With this in mind you could say that there is only one hazard to watch for when having nail extensions applied, this being a 'bad technician'. Acrylic Nails are made with two substances a liquid and a powder which form together to create the nails. The safe and correct liquid used for nails contains a substance called EMA (Ethyl Methacrylate) the damaging liquid contains MMA (Methyl Methacrtylate). MMA liquid should not be used for nails, it is for the dental industry (where acrylic nails originated from). It is used to make crowns for your teeth. Serious adverse skin reactions and permanent nail deformities are only part of the risks of using MMA. MMA creates extensions which are too rigid for the natural nail plate. MMA extensions resist breaking if accidentally caught or jammed. This often leads to painful breakage of the nail plate near the cujticle, which may result in severe infections. A good salon and well trained technician will know the dangers of using MMA (Methyl methacrylate) instead of Ethyl methacrylate (EMA), a more expensive and safer bonding liquid. Look out for salons who are not willing to show you the products which they use. For a more in depth article and how to tell if a technician is using MMA please follow the MMA Fact Sheet: Many technicians will use an electric drill which is fine when shaping the extension, however, under NO circumstances should a drill ever be used on the actual nail as this will lead to permanent damage. When you visit a salon watch to see if the technician uses a sterilising agent on her hands and yours. Check to see if she/he is qualified, are the tools cleaned between each customer and are the products readily on display or hidden away?