ABSTRACT
The idea of making straight hair permanently curly is not new. The first permanent hair waving procedure was developed by Nessler in 1906 and consisted of a borax paste applied to the hair followed by the use of external heat in the form of electrically heated hollow iron tubes. Later it was refined by combining the borax paste with heat generated by a chemical heating pad attached to the curling rods with a clamp. Temperatures reached about 115 degrees Centigrade and heating continued for 10-15 minutes.1 Unfortunately, this procedure was very damaging to the hair. The idea of the cold permanent wave was introduced in the 1930s and immediately replaced the heat wave method. The cold waving solution contained ammonium thioglycolate and free ammonia at a controlled pH. This technique was patented in the United States by McDonough on June 16, 1941. Interestingly enough, this cold wave solution, with slight variations, is still popular today for both salon and home use. It is estimated that more than 65 million permanent waves are sold in salons and 45 million home waves are performed on an annual basis in the United States.2
