MMA is an acrylic liquid sometimes illegally used in nail applications. It originates from the dental industry and when used on nails MMA can cause serious health risks. MMA has an overpowering strong odour.
Nail technicians have to wear masks to protect themselves from the dangerous vapours. Nail technicians using MMA will nearly always use a nail drill or electric file because MMA acrylic is too hard to file with a hand file. Removing MMA acrylics is very difficult.