Head protection devices must be worn in locations in the workplace where there is a risk of receiving head injuries from flying or falling objects and electric shock.
Hard hats are described by impact type and electrical class. All hard hats required must meet Type I (blows to the top of the head) or Type II (blows to the top or side of the head) impact requirements.
Classes of hard hats are all designed based on ANSI-Z89.1.
Class C: Conductive; No risk of head injury from contact with electrical conductors. Only classified as injury from flying or falling objects.
Class G: General; Reduce danger of exposure to low-voltage electric or flying or flying objects.
Class E: Electrical; Designated for exposure to high-voltage electric conductors up to 20,000 volts.