Given the high use of propellants, it is not surprising that butane was the most abundant compound. This compound is widely used as a propellant in spray products such as lacquer and foam for techniques such as bend and hairstyling. In recent years, manufacturers have focused on the development of hair care products with a reduced or zero content of butane. The use of these environmentally friendly products is reducing butane consumption and its concentration in hair salons. In fact, the hairdressers who mainly used ecological products worked in environments with lower levels of butane: HS1, HS4, HS9 and HS10