Is the Australian glove safety standard AS/NZS 2161 right for you?
Monday, 22 March, 2010
The current international standard for gloves designed to protect against mechanical injury is EN 388, which has been adopted word for word by AS/NZS 2161. However, this standard has a number of shortcomings. In particular, the performance tests are often misconstrued and often do not reflect the environment in which a glove may be used, or the glove’s actual performance in all-too-common circumstances.
This article briefly reviews the four performance tests covered by AS/NZS 2161 (abrasion, cut, tear and puncture) and lists a few considerations that should be made when interpreting the results and selecting gloves.
This test utilises an instrument called a ‘Martindale tester’ with 300 g/m2 glasspaper as the abrasive that moves in a circular motion over the material being assessed. Considerations:
- Is glasspaper a suitable medium to assess abrasion resistance? My immediate thoughts are of the overwhelming number of abrasive-paper options available from DIY stores, each designed for a unique circumstance and application.
- The variability of quality of the abrasive across laboratories is questionable.
- For gloves that comprise multiple layers, each layer is tested separately and the performance level is based on the lowest individual result of the most resistant material.
- There is a large and inconsistent increase in performance between reported levels, ie, from Level 3 (200 cycles) to Level 4 (8000 cycles).
- The test only considers the palm area of the glove.
The ‘Coup test’ involves a circular blade moving back and forth over the sample material, rotating in the opposite direction of travel, under about 500 g of cutting force.
- Is this a suitable test for cut resistance? Most lacerations result from a single strike of great force, rather than from a repetitive low-force action.
- Test calibration - the test blade is calibrated before and after the test using a standardised piece of canvas. The post-test calibration is used as a divider to the overall index, meaning that if two passes are required to cut the standard canvas, then the number of observed passes during the material test is divided by two.
In this test, a sample of material is prepared in a standard way and clamped in the jaws of a strength-testing machine. The jaws are moved apart at constant speed and the force needed to tear the material measured. For single materials, the performance level is given by the lowest result of four tests. For multiple layered materials, each layer is tested separately, with four tests carried out on each material. The performance level is based on the lowest individual result of the most tear-resistant material.
This test uses a 4.5 mm rounded point that is pushed through the material at a fixed speed of 100 mm per minute and the force required for the point to penetrate through the material is measured.
- Size of test probe - The test probe is something representative of a roofing nail, which may not necessarily represent the types of exposures most commonly seen in the workplace, ranging from needles to glass and metal shards, wood splinters and wire.
- Speed of the test probe - The test probe moves at 100 mm per minute, which poorly reflects real-life hazards (does anything mover that slowly?).
- The test probe is more accurately a stress test, measuring the force required to force the fibres apart, or until they break. Punctures from needles or shards have a cutting action as it pierces the fabric and this is not assessed in the test.
- Only the palm area is measured, despite most injuries occurring between the fingers and on the back of the hand.
A few more considerations of AS/NZS 2161:
- The standard only considers the palm area of a glove. No consideration is made for the fingers or the back of the hand, which is often most vulnerable and where most workplace injuries occur.
- Environmental conditions have a huge effect on performance. Test laboratories are dry and controlled. But the performance of some materials and glove designs are greatly affected by oil, water or ultraviolet light, none of which are considered in the standard.
Despite the standards that exist today, we must make our own conclusions about the suitability of the tests used to measure a particular hazard. We have to transition from using the AS/NZS 2161 results as the final answer to using them as an initial guide. As you make decisions on glove selection, consider the AS/NZS 2161 results and any supplemental test, but then do your own real-world safety test on the job. Consult with glove specialists and, most importantly, make sure that the tests are representative of the hazard you are trying to mitigate.
|Characteristic||Level 1||Level 2||Level 3||Level 4||Level 5|
|Abrasion resistance (# of cycles)||100||500||2000||8000||-|
|Cutting resistance (index)||1.2||2.5||5.0||10||20|
|Tear resistance (Newtons)||10||25||50||75||-|
|Perforation resistance (Newtons)||20||60||100||150||-|
*Damione Wright, Wrights HardWear Pty Ltd
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