A systems approach to PPE
September 11, 2009
When selecting head protection equipment, buyers frequently overlook the need to protect the entire head, not only the top of the head. A well-designed safety helmet system will provide protection for a worker’s head, face and ears. Comfort and weight are key issues that should be considered, as accessories will add weight. Another factor is to select accessories that match the application hazard correctly, protecting workers from impact, high noise levels, electric arc explosions, ultraviolet light, infrared radiation or heat exposure.
The first step is safety helmet compliance with the ANSI Z89.1 standard. The latest edition of the standard is ANSI Z89.1- 2009. ANSI Z89 covers the minimum performance requirements for helmet protection from impact and penetration, and classes of protection from electrical shock. Type I helmets are designed to reduce force from blows to the top of the head, while Type II helmets are designed to reduce the force of blows to the top or side of the head. Class G helmets are designed to reduce the danger of low-voltage conductors, proof tested at 2200 volts; Class E helmets are proof tested at 20,000 volts, while Class C helmets are not intended to provide protection against contact with electrical hazards. Vented helmets are rated Class C and non-vented helmets can be rated Class G, E, or C.
As buyers evaluate safety helmet designs, they find many features available that are not specified in the standard itself. These include the size, shape and slope of the brim, the type of suspension, the comfort of materials used for the suspension and brow pad and the presence or lack of a nape guard, accessory slots, rain trough and venting options. Suspensions are offered with either pin-lock or ratchet-size adjustment, and with four or six points of fabric or plastic materials.
After buyers finalize the specification, then they evaluate style and comfort to find the best choice for their workers. Taking these steps into consideration will result in a safety helmet that projects a positive image of your company. Style, fit and functionality are all factors that will motivate workers to use head protection equipment throughout the work shift.
Most major brands of hard hats have built in-slots for adapting accessories. Accessories called “blades” fit into slots and are combined with cap-mounted ear muffs and/or visor brackets with a face shield. This systems approach allows the user to rotate and slide into position the ear muffs and to flip up and down a face shield as needed. Holding the shield in the up position for an extended period of time is often required. Keep in mind that a system must overcome the weight of large shields and chin protection to be effective.
Some safety helmet manufacturers offer fiberglass materials for hot environments, and these are typically “unslotted.” For fiberglass helmets, there are reliable methods for adapting accessories that can be attached to the rim to create a slot. Once the slot has been fitted in place, accessories like ear muffs and face shields can be added to create a complete system.
A helmet system that is properly designed and integrates all components will insure worker safety. The accessory “blades” should fit snug and secure in the slot. User problems are avoided when the visor bracket spring tension has adequate strength to prevent face shields from flopping up and down.
Another concern is how to reliably integrate hearing protection on the safety helmet. Cap-mounted ear muffs are an excellent option, positioned to rest on the hard hat and ready to cover your ears when entering a noisy environment. It is important that both the ear cups and hard hat are designed so that the ear cup can easily cover the ear without being restricted by the hard hat rim. Recesses in the muff ear cups and/ or recesses in the hard hat rim are ergonomic designs that insure a good fit and protection. The level of protection available with cap-mounted ear muffs is as high as 28 dB NRR (noise reduction rating), providing a high level of attenuation. Many cap muffs are equipped with channels so the face shield’s visor bracket slide in and out to position the shield so it is just the right distance from the face.
It is important to properly select face shields for the specific application hazard. Various models of face shields are available to match these hazards. Impact resistance that meets ANSI Z87 requirements is provided by polycarbonate or Lexan face shields and nylon or steel mesh visors. Electric arc protection is a requirement for many electrical workers and shields that meet NFPA 70E requirements can be integrated in a safety helmet system. Other shields provide infrared protection for welding and others are gold coated to withstand high heat molten metal applications. Note that when wearing face shields, OSHA requires that safety glasses be worn at all times.
With careful selection and design of components, workers will benefit from wearing a safe and comfortable integrated head protection system.