Hard hats are also known as safety helmets, an item of PPE (personal protective equipment). Hard hats protect your head from falling objects and impact from other objects also protecting from electrical shock. Hard hats are worn within roofing and construction, also in forestry and offshore industries. They can be worn any environment by anyone. Hard hats are a legal safety requirement for you to wear on construction sites worldwide.How are they constructed?Hard hats are made from strong plastic such as HDPE (high-density polyethylene). There are suspension bands within the helmet that spread impact force over the top of the head, reducing injury. Hard hats can be supplied with a chin strap or ratchet adjustment keeping the hat firmly in place. Some models are vented to keep your head cool whilst working, for example, the Petzl Helmet range.Types of Hard HatsThe helmet type defines the impact protection.Hard hats provide impact protection from objects hitting the top of your head.Hard hats provide protection from top and lateral impacts. You are protected from objects hitting the top of your head and from the side, or off centre.Hard Hat ClassesThe helmet class defines the level of electrical protection.Class E (Electrical) hard hats provide protection against falling objects and electrical exposure up to 20,000 V.Class G (General) hard hats offer protection against falling objects and electrical exposure up to 2,200 V.Class C (Conductive) hard hats offer protection from falling objects but provide no dielectric protection from electrical exposure.What colour do I need?Hard hats are available in many colours. There is no legislation defining the colour you should use, but many construction sites use colours to identify job roles. For example, yellow hard hats are worn by general labourers and those involved in earth moving work. White hard hats are used by managers, supervisors and architects. Brown hard hats are worn by those working with equipment at high temperatures, such as welders.How often should I replace my hard hat?If your hard hat is damaged, you must replace it immediately. If it isn’t damaged, still change it periodically. Most manufacturers advise that a hard hat has a lifespan of two to five years.