White Papers

Redefining Hand Protection: A New Approach Based on Real Life Use and Risk

Dec 16, 2016 • WHITE PAPERS
Protective Industrial Products

Over the years, the industry has struggled to equate cut resistance with actual
risk. The recent updates to the ANSI 105 and EN 388 will provide a more uniformed
approach to assessing the cut resistant performance of gloves across
the globe. While this will make the cut scores more comparable, it will not help
safety managers determine which cut score is best suited for the job.

 

Regardless of these changes in test methods and cut score scales, customers
will still ask: "What glove and what cut level should I be using?" When customers
don't get a clear answer, they typically err on the side of caution and select the
glove offering the maximum cut score, only to discover that the high cost is
unacceptable and unsustainable.

The ultimate objective is for customers to choose the right glove for the right
job and that means equating glove specifications to something realistic, like
risk of injury. It is the intent of this article to outline a new and unique approach
to assessing cut risk, which takes a comprehensive look at all factors involved.
Before going further, it is important that we take some time to review the basic
fundamentals related to cut resistant fibers and types of grip coatings.

MATERIAL BASICS AND PERFORMANCE

 

Steel and glass were among the first technologies used in cut resistant apparel.
Both are naturally hard materials and can be easily formed into sheets or even very
thin fibers. Stiffness typically relates to how hard something is, and the greater
the stiffness, the greater the possibility of breakage, especially when repeatedly
flexing very thin fibers or yarns. This is the reason why steel and glass-based
gloves were predominantly replaced with more advanced materials that yielded
better performance in flexing. Having said that, glass and steel continue to be
used today but are now engineered with more advanced materials such as HPPE
(High Performance Polyethylene, such as DSM Dyneema®) and Aramids (such
as DuPont® Kevlar®) to produce cut resistant gloves and sleeves that are more
comfortable and flexible. Depending on the blend of materials and structure of
yarn, we can easily go from a very inexpensive blend (predominantly glass) offering
very high initial cut scores, to more expensive engineered yarns that make use of
fully encapsulated glass, steel or mineralized materials for ultra-high cut resistance
and all-round performance. It is important to highlight that gloves made from
predominantly glass fibers achieve high initial cut scores simply by dulling the test
blade. However, the inherent stiffness and brittle nature of glass fibers cause it to
fibrillate quickly, resulting in possible skin irritation, fatigue and premature wear.

The issues described above has led to the proliferation of High Performance
Polyethylene or HPPE, as it's more commonly known, and Aramids such as
Kevlar® to become the fibers of choice in providing superior cut protection in
gloves and sleeves. Both materials are inherently strong with HPPE offering
coolness and comfort, while aramids provide, depending on thickness, light to
medium heat protection. Until most recently this superior comfort and performance
could only be gained by using higher quality HPPE and aramid-based fibers
blended with spandex or nylon for extra flexibility and performance levels. 

But all that is changing. Today, the approach by leading glove suppliers is to
develop proprietary engineered yarns, using HPPE or aramids, along with novel
technology that embeds, encapsulates or blends multiple strong fibers such
as glass, steel or mineral-based materials that, until recently, could not even
be imagined – let alone mass produced. Advancement in nanotechnology is
allowing us to work with incredibly strong materials, previously thought to be
too thick or too stiff. These natural materials can now be formed into nano-thin,
highly flexible fibers that when blended or encapsulated with HPPE or aramids,
produce a whole new generation of gloves and sleeves that offer sustainable
performance and dexterity. The overall benefit to the user is lower cost, higher
cut resistance, improved flexibility and outstanding wear performance. That's
innovation in today's world. 

CHOOSING THE RIGHT PROTECTION

 

With the advancement in materials as described above, we can feel confident
that gloves and sleeves produced today are among the best we've ever seen.
However, making the right selection only gets harder with more choices. As
mentioned at the beginning of this article, we made a point that cut scores cannot
be relied upon as the sole indicator of performance because if it were, then
cheap, glass blended gloves with very high initial cut scores would be the glove
of choice for everyone. We went on to explain that there has to be more to
glove and sleeve selection than simply cut score. In fact, we would argue that
we must consider factors in real working applications like the force applied and
sharpness of the edge threat, and equate that to the risk of injury.

With the exception of contusions, most skin injuries are a result of contact with a
sharp edge or even a burred, rough edge on fragile skin. Using a glove or sleeve
layer helps reduce the likelihood of damage to the skin. We say "reduce the
likelihood of damage to the skin" because it is understood that nothing is truly
cut proof. With enough force energy, driven either by motion or weight, almost
anything is penetrable. 

The extra layer offered by a technical glove today consists of a knitted or fabric liner,
coated with a natural or synthetic rubber polymer. Traditional gloves made of thick leather
may seem to offer comparable protection, but this is not the case. While leather may
offer some abrasion protection, it slices effortlessly when in contact with a sharp edge
making it no match for gloves using the latest technology, cut resistant fibers and yarns.

In the case of coating, thicker, tougher coatings will offer extra protection especially
when contact with burred, rough edges is a necessary part of the task. An example of
this would be handling heavy sheet metal or working with castings. The coating grip also
plays an important part in preventing a sharp part or knife from slipping and allowing its
blade or cutting edge from making direct contact with the gloved hand or arm.

It can be argued that a cut resistant liner should act as the last line of defense for
protecting skin and that avoiding any direct contact with sharp edges. Edge sharpness
and force of contact are critical factors in determining whether the glove or sleeve
material type will be able to defend against contact with the underlying skin. Proper
selection is multi-factorial and for this reason we deemed it necessary to develop a
unique approach to help determine the risk and possible severity of an injury

WE INTRODUCE TO YOU THE CUT RISK HAZARD MATRIX™

 

The CUT Risk Hazard Matrix™ is a unique and logical method to guide
users in selecting a glove or sleeve with the right cut resistant material and
score. Once a safety manager can identify where their application fits on the
CUT Risk Hazard Matrix™, they can more confidently correlate the task to
the glove or sleeve best suited for their job. 

CUT RISK HAZARD MATRIX™

 

The illustration of the CUT Risk Hazard Matrix™ below demonstrates the factors involved in determining applications for
cut resistant gloves or sleeves. 

By plotting the tasks and applications, we determine a CUT Risk Hazard
Factor™ (CRH: Factor™) as outlined on the right side. The CRH: Factor™ is
a comparative indicator that helps safety managers determine the level of
potential hazard related to the task or application. To explain further, the Force
Exposure vertical axis tries to relatively quantify how much possible force may
be applied if there is edge contact with the glove or sleeve. It is obvious that
a higher force will occur when handling heavier or moving parts. The Edge
Sharpness axis on the bottom correlates to the sharpness of the cut threat with
10 being a razor-sharp blade and 0 representing a rough edge, such as that of
a brick or masonry block.

Correlating these two important factors is essential to determine the possible
severity and type of trauma they will produce. Let's use a worker who is handling
box cutters in a repacking operation as an example. The force required to open
tape on boxes may be determined to be at a level 5, while the edge of the blade
is no doubt razor sharp, placing it about 10 on the Edge Scale – altogether we'd
express this as a CRH: Factor™ 5:10. Correlating the CRH: Factor™ 5:10 on
the CUT Risk Hazard Matrix™ is easily equated to the ANSI Cut Scores, as can
be seen in the matrix below. 

CONCLUSION

 

Selecting Cut Resistant gloves or sleeves is not a linear science and choosing the
highest cut level is not necessarily the best protection or best product for dexterity
and productivity. We can see that proper glove selection is multifactorial and based
on understanding the fundamentals of risk and task while carefully assessing the
needs. We all seek a one product, one level solution but that is just not the best
solution – even with today's advanced fiber materials and engineered yarns. Our goal
is to work within the industry to help everyone become better acquainted with proper
glove and sleeve selection. We believe that the CRH: Factor™ values help to more
confidently assess the requirement and better correlate to EN and ANSI cut scores,
while serving as a guide for product selection to meet price points and conditions. As
a leading provider of hand and arm protection, PIP believes it is incumbent upon us
to help safety managers and workers make confident glove and sleeve selections. 

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