The Variations in Test Methods
Last Century a European Standard EN388 was created to help determine which glove may best suit what application. It was known as the ‘Protection against Mechanical Risks’ Standard for hand protection and tested for Abrasion, Cut, Tear and Puncture resistance. In this Standard the Puncture test was conducted by a 5mm steel probe (Pencil size) with a rounded point tip 1mm wide. This probe pressed against the glove palm at a right angle travelling at 100mm/minute. This rather thick object travelling at a slow speed tended to bend, stretch and eventually burst through the material. This test is particularly relevant to static spikes, thick splinters or wire, edges of steel / aluminium.
In November 2010 a new standard test method ASTM F2778-10 was introduced for ‘Protective Clothing Material resistance to Hypodermic Needle Puncture’. In Feb 2016 the American ANSI/ISEA 105 Standard was updated to include the ASTM F2878-10. This is now the internationally recognised testing procedure specifically for needle resistant gloves. In this test the fine point Needle travels at 500mm/minute, measuring the amount of force to pierce (Needles have a precise bevelled edge) then pass through material in Newtons force.
Today some manufacturers are persisting with older test methodologies that are not specifically designed to test hand protection such as the Modified ASTM F1342-05. Some manufacturers are quoting glove performance in other than the Standard International unit of Force which is the ‘Newton’. It is only when you convert their alternate unit measures of force that you can have a clearer appraisal of the actual protection factor. If your glove manufacturer is providing you with measure of force in 1 Pound / foot (lb/f) this equals 1.3558179 Newton-meters. Others will provide force in Grams 1 = 0.00980665 Newtons.
Take note of the gauge (diameter) of Hypodermic Needle used in the testing. The 25g Needle is the accepted standard gauge for industry testing. Some tests are conducted with 23g as the wider Needle tip delivers better performance results (the smaller the gauge number the wider the needle). We find real world reference to gauge when a commonly provided ‘substance addiction’ or Diabetes Needle is 19, 23 to 25 gauges in thickness.
It is very relevant to understand that many so-called “Needle (Stick) Resistant” gloves as advertised, are not providing a very high level of Needle puncture resistance. Some of the popular well-known brands are as low as 1.2 to 3.5 Newtons of protection. To put this into perspective the highest level of performance currently able to be manufactured is just over 10 Newtons. These upper and lower performance measurements position a Hypodermic Needle resistant glove providing 5 to 6 Newtons in the mid-range of protection.
It is in this mid-range performance level that we find the “sweet spot” as far as working with some hand mobility and dexterity in Needle resistant gloves. That is, the provision of adequate levels of protection without creating unnecessary feeling of clumsiness or increased discomfort, lack of sensitivity, wearer hand / finger fatigue.
As long as there are established processes in place for steady and controlled movements in a low to mid level of potential risk work zone, these gloves should prove to be suitable. For those tasks where the hazard is unknown, or a higher level of protection is required, then the 10 Newtons rated gloves will provide the maximum puncture resistant performance.