When operating in situations where falling objects could cause injury to the head, hard hats are essential. Additionally, hard hats designed to reduce electrical shock are also required when working near exposed electrical conductors that may make contact with the head.
Hard helmets featuring miner’s lights, reflective stripes for night work, face shields for welders, and attachments for visors or earmuffs are all examples of specialty hard hats.
Basics of Hard Hat Design
Hard hats are designed to be lightweight, with a suspension that fits comfortably on the head. Hard hats should fit snuggly but not tightly. Suspension systems will vary from one manufacturer to another. For example, some hard hats feature ratchet-style suspensions that can adjust in all directions, while others feature a rear strap that tightens by pulling a tab. In addition, some hard hats may feature shields that workers can place over and around the head for additional protection.
The primary function of a suspension system is to absorb impact, but it also must allow for good visibility and hearing without the hat itself getting in the way. Therefore, hard hats should have adequate space from ear to ear to ensure good hearing, and vision goggles or face shields should be worn when necessary.
Hard hats are often used for industrial and construction purposes, but workers in other fields may also be required to wear them under OSHA standards or company policies.
Common Scenarios in Which Hard Hats are Necessary
Hard hats should be worn when there is a risk of falling objects because of activity near:
- workers or operations where a head injury could result from the unintentional dropping or loss of material, tools, equipment, or other things.
- a blocked or posted demolition or construction zone where there are potential head dangers.
- Objects on shelves, platforms, and other surfaces that could fall and cause a head injury; or
- Nearby electrified conductors overhead.
All hard hats are required to meet the requirements of the ANSI Z89.1, American National Standard for Personal Protection – Protective Headwear for Industrial Workers.
The hat’s suspension mechanism is meant to help absorb and diffuse impact while maintaining a space between the head and the hat’s shell. The hat’s class is usually written on the inside of the shell.
Types and Classes of Hard Hats
Type 1 – Helmets designed to lessen the impact power of debris so that just the top of the head is struck.
Type 2 – Helmets designed to lessen the force of an impact that causes a blow to the top and side of the head.
Class E (Formerly Class B) – Non-conducting hard hats designed to guard against falling items and limit the risk of high voltage electrical shocks and burns in situations where electrical hazards exist (such as in utility services). With high-voltage shock and burn protection of up to 20,000 volts, it provides the best protection.
Class G (Formerly Class A) – Meant to guard against falling objects and prevent the risk of exposure to low voltage electrical conductors. Impact and penetration resistance are provided, as well as protection from up to 2,200 volts.
Class (Formerly Class C) – Electrical resistance is not evaluated on Class C hard hats. They are not intended to protect against electrical conductors and are designed for lightweight comfort and impact protection.
Hard Helmet Limitations and Wear Factors
The headbands, chin, and nape straps of hard hats should be adjusted to comfortably maintain the hat on the head. Warmth or cooling can be achieved by using liners or sweatbands. When the shell or other pieces of the hat become damaged, they should be replaced.
Hard hats may be cleaned by soaking them in hot water with detergent, scrubbing the shell, and then rinsing them in hot water. However, cleaning solutions have the potential to harm the shell.