Hand impact injuries
Knocks, bumps, and pinches can cause a range of hand injuries from bruises to broken bones. Like most hand injuries, these impact injuries can be reduced and prevented. But, with the dizzying selection of safety gloves on the market, how do you choose the best protection for your workers?
To select the best level of protection for your workers, start by reading this guide where you will learn
Forces at work in impact-resistant gloves
We know impacts like knocks, bumps, and pinches cause impact injuries like bruising and broken bones, but what exactly causes an impact injury?
When an object strikes or pinches a hand, force is transferred from the object to the hand. The power of this force is what causes a shift or displacement of skin, bones, and muscles that leads to injuries such as lacerations, bones breaking, and bruises.
How impact-resistant materials
work to prevent and reduce injuries
To reduce or prevent impact injuries, the key is to increase the time over which the impact occurs. This way, the hand does not absorb all the impact at once. Instead, the force of the impact is spread over time, lessening the severity of the impact. In other words, you’re trying to minimize the peak force that your hand experiences. The primary way to achieve this is through deformation.
Deformation is achieved using impact-resistant back-of-hand materials (also known as bumpers), which are attached to the glove shell. Ultimately, the goal of the bumpers is to optimize deformation, so the impact force is slowed as much as possible.
A simpler way to understand deformation is to imagine landing on a firm mattress versus a concrete floor from a significant distance. As you hit the mattress, it stretches when you land and bounces you a couple of times before your body finally comes to a stop. Now if you land on a concrete floor from the same height, you come to an immediate stop all at once. But in this case, you transfer an incredible amount of force into your body, sustaining more severe injury. The result in both instances is the same. You come to a stop! But, in the case of landing on a mattress, impact force is transferred much more slowly, decreasing the likelihood and severity of injury.
This is exactly how we think about manufacturing impact-resistant safety gloves.
Deformation is the ability of impact-resistant material to slow the impact force transferred into the hands. It does this by deforming, or changing shape temporarily, to slow the force and lessen its impact on the hands.
Impact-resistant bumpers form a rigid rubber padding that covers the back of the hand, knuckles, and fingers as shown.
There are three key components to how we innovate bumpers to achieve the best impact protection for workers.
As discussed earlier, to achieve effective protection from impact hazards, materials used for the bumper must be optimized for deformation to reduce the impact absorbed by the hands. One of the most common impact-resistant materials used to achieve this is TPR (Thermoplastic rubber).
TPR is one of the most common materials used to achieve impact protection and performs well at a relatively low thickness. It has shock-absorbing properties and offers high durability for bending, stretching, and moving. All this helps maintain range of motion for workers to work comfortably while also providing impact protection. TPR also performs well in cold and hot environments.
Impact-resistant bumper design and placement
At Superior Glove, we leverage technology to maximize impact protection beyond the inherent characteristics of a single material. To do this, we engineer material blends and incorporate innovative designs and bumper placement that improves our gloves’ performance under impact while maintaining as much comfort and dexterity as possible.
Our TenActiv™ STXFNVB uses patent-pending skeleton bumpers to allow high dexterity while providing maximum ANSI Level 3 impact resistance.
Our 4Pro Goatskin Driver gloves, using our proprietary blend, offer the industry’s highest level of impact protection (ANSI Level 3 impact resistance) without increasing bumper thickness.
You know your workers face impact hazards, but how do you decide which level of impact protection to buy?
To help you decide, industry standards were established with specific testing methods to assign protection levels for safety gloves, including impact resistance. These standards were introduced to create a common language for safety managers, distributors, and manufacturers to define protection levels and substantiate protection claims.
There are three industry standards governing impact protection
North American Standard (ANSI/ISEA 138)
The ANSI/ISEA 138-2019 standard established the minimum performance, classification, and labeling requirements for gloves designed to protect the knuckles and fingers/thumb from impact. Three performance levels are used to classify impact resistance: level 1, 2, and 3, with level 3 offering the highest level of protection.
When looking for impact protection levels on gloves, the ANSI impact level is represented by the following icon:
The palm of the impact-resistant glove is cut away, so the testing area only includes the back of the glove’s shell and the impact absorbing material. This halved glove is then placed on a metal anvil with a special force transducer underneath to record how much force goes through the glove. Next, a 2.5 kg striker is dropped on the testing location, imparting 5 joules of energy into the glove. The force transducer records the impact force. This test is repeated for each knuckle, finger, and thumb (knuckles are tested four times while fingers and thumbs are tested five times). The average of the knuckle tests is compared to the average of the fingers/thumb tests to determine the final impact testing score:
· Level 1: Allows an average of 9kN (kilonewtons) or less of force through the glove.
· Level 2: Allows an average of 6.5kN or less of force through the glove.
· Level 3: Allows an average of 4kN or less of force through the glove.
EN388 European Standard
Compared to the ANSI/ISEA 138-2019 standard, the EN388 dictates fairly limited testing criteria for impact protection. Under this standard, the same testing method is used as ANSI/ISEA, but only the back-of-hand material on the knuckles is tested, not the fingers or thumb. Under this method:
· If the average transmitted force is less than or equal to 7kN, then the gloves receive a pass rating, indicated by the letter “P” on the EN388 standard shield
· If the average transmitted force is higher than 9kN, then the gloves receive a fail rating, indicated by the letter “F” on the EN388 standard shield
· A letter “X” indicates that a glove has not been tested
An example of the impact-resistant markings can be seen in the image below.
UK Conformity Assessed (UKCA) Standard
There are no differences in testing methods and ranking levels between the European Union and United Kingdom standards. However, PPE sold in the UK is mandated to have an icon (as shown) to certify they conform with UKCA (UK Conformity Assessed)