HELMET

HELMET is a form of protective gear worn to protect the head. More specifically, a helmet complements the skull in protecting the human brain. Ceremonial or symbolic helmets (e.g., a policeman’s helmet in the United Kingdom) without protective function are sometimes worn.

A good helmet can absorb some of the impact of a collision—A well-constructed helmet will help dissipate the force of a blow or bump to the head, so that there’s less energy directed at your head or brain.

Helmholtz function is a thermodynamic function which is defined as the decrease in the function and is equal to the maximum amount of work which is available during reversible isothermal process.

Safety helmets are an essential piece of personal protective equipment (PPE) that is designed to protect the wearer from head injuries caused by falling objects, impact with stationary objects, or electrical hazards.

What standards do safety helmets have to meet?

General industry helmets must comply with EN 397:2012+A1:2012. In addition, industrial helmets can also comply with EN 50365:2002 as electrically insulating helmets for use in low voltage installations (5-RS, 5-RG and CURRO helmets).

There is also a special standard for sports helmets, eg for use in mountaineering. Helmets for mountaineers must comply with EN 12492:2012 (CADÍ and MAKALU91 helmets).

This standard includes many of the requirements of an industrial helmet and it is common for a mountaineering helmet to be able to meet the requirements for impact protection.

Purpose

Hard hats are required when working in areas where there is a potential for injury to the head from falling objects. In addition, hard hats designed to reduce electrical shock are required when working near exposed electrical conductors that may contact the head.

Specialty types of hard hats include those with miner’s light attachments, reflective stripe for night work, face shields for welders, and attachments for visors or earmuffs.

Use of Hard Hats

Hard hats should be used when falling object hazards may result from activities with proximity to:

• persons or operations where accidental dropping or loss of material, tools, equipment or other articles could lead to a head injury;
• a barricaded or posted demolition or construction area where head hazards exist;
• objects stored on shelves, platforms, etc. that may fall and cause head injury; or
• overhead exposed energized conductors nearby.

Hard Hat Design Standards

All hard hats must comply with ANSI Z89.1, American National Standard for Personal Protection – Protective Headwear for Industrial Workers – Requirements. The suspension system inside the hat is designed to help absorb and dissipate impact while keeping a clearance between the head and shell of the hat. The class of hat is usually noted inside the hat shell.

Types and Classes

• Type 1 – Helmets intended to reduce the force of impact resulting in a blow only to the top of the head.
• Type 2 – Helmets intended to reduce the force of impact resulting in a blow to the top and the side of the head
• Class E (Formerly Class B): Helmets for sue where electrical hazards are present (in utility services) that are non-conducting and intended to protect against falling objects and reduce the danger of exposure to high voltage electrical shocks and burns. Offers the highest protection with high-voltage shock and burn protection up to 20,000 volts.
• Class G (Formerly Class A): General Use (limited voltage – non-conducting) intended to protect against falling objects and reduce the danger of exposure to low voltage electrical conductors. They provide impact and penetration resistance and protection from up to 2,200 volts.
• Class (Formerly Class C): Class C Hard Hats are not tested for electrical resistance.  They are designed for lightweight comfort and impact protection and are not intended to provide protection from electrical conductors.
• Safety helmets can be classified:

  HELMET