Utilized since antiquity, asbestos is primarily valued for its fire resistance, but is also appreciated for its strength, low electrical conductivity, and elasticity. The fiber was not commercially produced on a massive scale, however, until the latter part of the nineteenth century when mining operations began in Italy and then Canada. For about 100 years, asbestos was widely utilized for a variety of applications. The longer fibers that were obtained were commonly spun into yarn used in break linings and insulation, while short asbestos fibers were generally included in paper products and cement-based building materials. However, since the 1970s there has been tremendous concern about the carcinogenic properties of asbestos and numerous restrictions on its production and use have been established in the United States and many other countries.