May 7, 2006
You might think that workers who put in more than eight hours a day in dangerous environments would want the very best head protection. After all, when they buy a helmet for their kids for riding their bicycles, they will pay upwards of $50 to protect their childâ€™s head for less than two or three hours a week of riding!
Yet when it comes to protecting their own head for a 40-hour work week, they wonâ€™t pay more than about one-fifth of their kidsâ€™ price. In fact, a worker or the employer will pay more than $100 to protect their feet, but less than $8 for their heads. This doesnâ€™t seem to make any sense.
Seventy percent of head injuries are caused from blows to the side, front or back of the head. The majority of hard hats are rated to protect a worker from the top. The hats that are rated to protect from the sides, front, back and top are more expensive (about $20) and represent about 20 percent of the sales of hard hats. If you think about it, a workerâ€™s working position doesnâ€™t have him looking straight ahead very often; he is typically bending over, looking left, right or sideways.
Workers need to understand some important facts about head protection and hard hats in order to maximize their safety. Letâ€™s look at seven key issues that can help keep workers protected.
1) ANSI, CSA and CE standardsThe Canadian Standards Association (CSA) was first to recognize the need for a new standard in 1991 with Z94.1-92. Shortly afterwards in Z89.1-1997, ANSI adopted a similar standard. In Z89.1â€“2003, ANSI again designated hard hats as Type I or Type II to differentiate the two types â€” Type I is the â€œvertical impactâ€ protection standard, and Type II is the â€œlateral impactâ€ protection standard. The testing for hard hats of both types includes penetration tests and employs a pointed object that strikes the hat. Furthermore, the hard hat is impacted on a spherical anvil to test for maximum Force Transmission. If the pointed object strikes the head, or if the force transmitted is higher than the permitted value, it fails and the manufacturer must correct the weakness before it can market the hat as an ANSI standard hat.
In Europe, the standard conforms to the designation CE.
2) E, G and C ratingsTo qualify for a class E rating, manufacturers must ensure that the materials used to make a hard hat â€” both the shell and the suspension â€” are dielectric, as a hat must pass an electrocution test that protects up to 20,000 volts. For a Class G rating (general purpose) the conductivity test must qualify with a protection limit of 2,200 volts. Lastly, to qualify for a class C rating, a hard hat may be manufactured of conductive material. This would only be suitable in areas where there is no risk of electrical hazard.
Some manufacturers vent their hats to try to provide a cooler hat for hot environments, but this voids both classes E and G â€” an essential factor to know when choosing one style hat over another.
3) Logos on hatsMany companies personalize their workersâ€™ hats by adding company logos or slogans. Imprinting doesnâ€™t affect the integrity of a hat, nor does an adhesive label. The problem with adding a label is that it makes it much more difficult to inspect the hat. Some workers will add a label to cover up a crack! A shiny label within a half-inch of the edge of the hat will also compromise a workerâ€™s protection.
What workers fail to realize is that a hard hat is a â€œone-time-hit onlyâ€ piece of personal protection equipment (PPE). A small crack will allow conductivity to pass through it, and it also compromises the impact protection.
If a hard hat falls onto concrete from a height of six feet or more, it should be thrown away. A company supervisor with responsibility for worker safety should regularly inspect the workersâ€™ hard hats for wear and tear. Hats with significant scratches and nicks should be replaced, as they have been compromised.
4) Hard hat maintenanceAn often-overlooked area in many articles of PPE is maintenance. Hard hats are no exception and must be inspected and maintained. A dirty hat covers up small cracks making it difficult to inspect. Too many workers donâ€™t read the manufacturerâ€™s instructions and not only donâ€™t maintain them, but fail to read about the hazards of wearing them backwards by inserting the suspension backwards.
A worker should never use solvents to clean a hat. Chemicals weaken the integrity of the shell. Always use mild detergents and water.
5) How theyâ€™re madeHard hats are typically manufactured out of high-density polyethylene (HDPE), a shell material that has absorptive properties. For applications requiring heat and spark resistance, some manufacturers use a polybutylene terephtalate (PBT) material. For additional lateral stiffness, manufacturers may use a copolymer of acrylonitrikbutadiene-styrene (ABS). There are two ways to increase impact absorption: a) increase the thickness of the shell; b) add a shock-absorbing liner. Some manufacturers have tried extra ribbing on the shell to provide additional absorption, but workers then had to deal with additional weight and inconvenience when it came to cleaning. The liner offers less additional weight but provides the same energy absorption. Hard hats have adjustable suspensions. This enables them to adjust form to the workerâ€™s head allowing for a tight fit. The standard hat uses a pin-lock adjustment mechanism while an upscale model uses a ratchet. Although the ratchet is a bit more expensive, its adjustment is easier and faster.
The performance test is the same for both systems â€” a static test that demonstrates retention before and after impact.
6) Human factorA company can â€œlead a horse to waterâ€ butâ€¦ Workers who have been educated about head protection and supplied with an appropriate hard hat may still circumvent the standard. They may refuse to wear one due to comfort and vanity issues. Thus, it is important to regularly make sure workers are actually wearing their hats.
7) Education and trainingAs with most PPE products, education and training are important aspects to the user. Manufacturers employ specialists who are trained to teach and inform company workers. How long will it be before everyone has to do it? Itâ€™s another link in the chain of due diligence.
Perhaps our example of comparing our childrenâ€™s head protection with our workersâ€™ head protection is somewhat extreme, but we must bring attention to this issue. We need to encourage safety managers to recommend a Type II hat for the future of head protection among workers throughout this country.