The Occupational Safety and Health Administration mandates that employees working in areas where there’s a danger of head injury from impact, falling or flying objects or electrical shock and burns — in other words, pretty much anywhere on a construction site — must wear appropriate head protection. And it’s up to the employer to provide it.

But not all hard hats are intended for all tasks. That’s why the American National Standards Institute (ANSI) classifies them by type and class as part of the ANSI Z89.1-2014 requirement that all new hard hats must meet.

Type I hard hats are meant to protect workers from top-of-helmet strikes only. Type II hard hats provide fuller coverage. Designed to protect the sides of the head as well as the crown, they typically have a thick foam inner liner (and are therefore usually heavier and warmer).

Hard hats also are differentiated by class. The class refers to how much (if any) protection against electrical hazards they provide.

Class G (General) hard hats will protect workers in case of contact with up to 2,200 volts of electricity. This is the most common type of hard hat and is suitable for general construction operations.

Class E (Electrical) hard hats will protect workers in case of contact with up to 20,000 volts. These are suitable for people working around electrical hazards.

Class C (Conductive) hard hats provide no protection against electrical hazards and are in fact conductive, which makes them more breathable. Unlike Class E hard hats, they can be vented.

Most hard hats are made from non-conductive, high-density polyethylene (HDPE), but some manufacturers use fiberglass for workers who work around operations that generate extreme heat. Carbon fiber helmets are tough and last longer but are more expensive than shells made with plastic or fiberglass.

Hard hats with more suspension points (some have four, others have six or eight) have a greater ability to disperse an impact over a wider area. They also distribute the weight of the hat more evenly for greater comfort.  

Although employers are responsible for providing employees with hard hats, many workers like to use their own. Employers should perform an inspection to make sure they’re using hats that meet ANSI requirements and offer the best protection against the hazards they’re likely to face.