OSHA requires head protection be worn in any environment where there is a potential for injury to the head [29 CFR 1910.135]. In addition, the head protection must comply with ANSI Z89.1 performance guidelines.
All hard hats are classified according to the specific impact and electrical performance requirements they are designed to meet. This classification is also commonly referred to as the ANSI Z89.1 standard.
Industrial head protective helmets meeting the requirements of the standard are classified as Type I for top protection or Type II for lateral impact protection. Both types are tested for impact attenuation and penetration resistance. Type II helmet performance requirements include criteria for impact energy attenuation from impacts from the front, back and sides as well as the top; off-center penetration resistance, and chin strap retention.
All hard hats in accordance with this standard meet or exceed either Type I or Type II impact requirements. In addition to type classifications, all hard hats are further classified as meeting Class G, Class E, or Class C electrical requirements. Each of these types and electrical classes are outlined below:
- Type I Hard Hats – Type I hard hats are intended to reduce the force of impact resulting for a blow only to the top of the head.
- Type II Hard Hats – Type II hard hats are intended to reduce the force of impact resulting from a blow, which may be received off center or to the top of the head. A Type II hard hat typically is lined on the inside with thick high-density foam.
- Class G (General) – Class G hard hats are intended to reduce the danger of contact exposure to low voltage conductors. Test samples are proof tested at 2200 volts (phase to ground). However, this voltage is not intended as an indication of the voltage at which the hard hat protects the wearer. Please note: Class G hard hats were formerly known as Class A.
- Class E (Electrical) – Class E hard hats are intended to reduce the danger of exposure to high voltage conductors. Test samples are proof-tested at 20,000 volts (phase to ground). However, this voltage is not intended as an indication of the voltage at which the helmet protects the wearer. Please note: Class E hard hats were formerly known as Class B.
- Class C (Conductive) – Class C hard hats are not intended to provide protection against contact with electrical conductors.