Hard hats and helmets protect workers from impact and workplace hazards. They are available in different types and protective classes set by ANSI (American National Standards Institute). Type I hard hats withstand vertical impact and penetration. Type II hard hats have an EPS inner liner that withstands vertical impact, lateral impact and penetration. Protective classes include Class E (Electrical), Class G (General) and Class C (Conductive). Class E hard hats provide the highest level of dielectric protection while Class G hard hats provide moderate protection. Class C hard hats are conductive and do not protect against electricity.