Cut Resistant Hand Protection

It is important to ensure that the right hand protection is of primary concern in every workplace. Lacerations are the #1 safety issue in most plants with common causes ranging from hand protection not being worn, poor compliance to PPE (personal protection equipment) programs and PPE simply misapplied. The COSTS of not doing so could be extremely heavy and are often not fully realized until after the fact. The Iceberg Principle for costs of injuries includes direct costs such as medical costs, workmen’s compensation and worker’s loss time. Indirect costs include hours lost to first aid, hours lost to assisting and transporting victims, hours lost to handling inquiries, cost of damaged equipment, administrative costs and lost hours used for investigation. These costs far outweigh the price of proper hand protection on all hands.  

On numerous occasions safety professionals in the supply chain walk into work situations where cost and safety are primary concerns. While most if not all companies put safety first, there is definitely a cost sensitivity that is hard to ignore. Advanced textile materials have come a long way in providing solutions that offer optimum protection at continuously more affordable prices. It therefore helps to have an understanding of these materials, the way they are tested and what those tests mean.  

Currently in North America there are two ASTM tests in practice to determine cut resistance of textile materials, one being the ASTM F1790-97 testing protocol and the other is the F1790-05 protocol. Both tests consist of a measurement of the amount of pressure applied to a razor blade while moving over the material in question without cutting through for 0.8 inches (05 Method) or 1,0 inches (97 Method). In principle, the higher the force/load (usually measured in grams) the material withstands, the better the cut resistance.  
 
Another process often referenced is the European standard EN388, which can be either a "Couptest" method for cut resistance or a TDM machine based test (a TDM machine test protocol is similar to ASTM). In general the Couptest consists of a circular blade moving back and forth across the material under a fixed force/load of 5 Newtons/500g while the blade rotates in the opposite direction to the back and forth movement. The test measures the number of repetitive cuts needed to cut through the material. The result is then compared to the cut resistance of a reference cotton material and provides a cut index.  As an example, an index of 5 means that the material is 5 times more cut resistant. The index is as follows:   

Level 0:  <1.2x
Level 1:  1.2x – 2.4x
Level 2:  2.5x – 4.9x
Level 3:  5.0x – 9.9x
Level 4:  10.0x – 19.9x
Level 5:  >20x
 
The EN388 test is also accompanied by abrasion, tear and puncture tests.
One thing that must be noted is because of the way these various tests are performed and measured, there is no cross-reference between the European and North American tests. It is not possible or proper to equate any result in the ASTM testing to any result in the EN388 testing.
The International Safety Equipment Association (ISEA) developed the "ANSI" table as a reference guide for test results from ASTM test protocols, these guidelines for cut resistance are: 

Level 0:  < 199g
Level 1:  200g – 499g
Level 2:  500g – 999g
Level 3:  1000g – 1499g
Level 4:  1500g – 3499g
Level 5:  >3500g

It is extremely important to understand the testing methods and testing levels quoted above and imperative to compare ‘apples to apples’. In North America safety specialists should ensure that firstly, the quoted levels are ANSI and not EN388 levels as they are not directly comparable. Further, even within the ANSI guidelines the spread is quite large for level 4 between 1500 and 3499 allowing for a vast and significant range of cut resistant products to achieve a cut level 4. Therefore it is always helpful to have not just the level that a particular product achieves but also the specific cut load (in grams) achieved in that range.  

While numbers and levels quoted above are extremely helpful in narrowing the range of product to use in a particular application it should not be the only qualifier. The testing and the subsequent level ratings simply provide a guideline which states that one material performed X and another material performed Y. One can gauge that if X>Y then the first material is more cut resistant – but only in the context of the test. Examining the tests, both are performed using a sharp razor blade under a controlled environment. In practice, most applications requiring cut resistance are not set in such a controlled environment. Some applications have parts that are oily, have a serrated edge or even have sparks and flames involved.  For these reasons, it is understandable to set a minimum level or cut test result as criteria for choosing hand protection, but not the only criteria. Careful examination of the application and any extraneous hazards which may be present, is an absolute necessity to select the correct or ideal hand protection.

Fo Abiad, President

Windsor Textiles Limited