In cosmetology, it is termed a type of curl reformation. Humans have been attempting to add curl to straight hair for thousands of years. The ancient Egyptians did this by wrapping their hair around wooden sticks; slathering it with mud from hot springs; letting it bake dry in the sun and then removing the mud. Presumably the mud had an alkaline chemical makeup that helped to set the curls. The safety of Permanent Waves is established by selection of ingredients that are safe and suitable for this purpose. In addition, Permanent Waves are rigorously assessed for their potential to cause scalp and eye irritation. Product safety is also established though strict adherence to the principles of Quality Assurance and Good Manufacturing Practices.