Cutting-edge hand protection
Trends in testingChanges in cut-protection testing procedures are driving current trends in cut resistance. A committee within the American Society for Testing and Materials (ASTM) International, comprised of representatives from fiber producers, protection manufacturers, testing labs and insurance groups, as well as academia, is responsible for developing a variety of test protocols.
ASTM subcommittee F23.20, Protective Clothing, Physical Hazards, has a task group that developed the cut test method F1790-97, which is used to determine the performance of a productâ€™s cut resistance against sharp edges. This test protocol was developed to measure cut performance for a variety of protective apparel including hand protective products. Most of the individuals who contributed to this test method are from organizations involved in hand protection. This test method and test equipment evolved from more than 20 years of study and refinement.
In order to reduce test variability and harmonize with the International Standards Organization (ISO) test standard for cut resistance, the ASTM committee in 2004 modified and adopted a newer version of F1790-97, also known as Standard Test Method for Measuring the Cut Resistance of Material used in Protective Clothing.
Key changes to the protocol that affect test values:
1) The reference distance standard used in testing was changed from 25mm to 20mm.
2) The conductive foil strip placement was changed to between the sample and the mounting tape instead of under the tape.
3) The reference load was changed from 400g to 500g on the blade calibration step with neoprene, and with the associated cut distances based on the individual machine type.
4) The tomodynamometer (TDM) test apparatus was included for global harmonization.
Itâ€™s been noted that products will receive different test values due to the changes between cut test versions 1997 and 2004.
The American National Standards Institute (ANSI) adopted performance standards for hand protection in 2000 (ANSI 105) at the recommendation of the International Safety Equipment Association (ISEA). Performance criteria was established based on work and canvassing from a group within ISEA. ASTM F1790-97 was the test protocol selected for evaluation of products for their cut-resistant value. Various product types and end uses were represented in this study and performance ratings from 1-5.
Cut test values for numerous products were considered when establishing performance levels. Products that had low cut-through values, such as thin latex or cotton, received a level 1, while high-performance and engineered yarn-based products typically received a level 4 or 5 rating due to the high load levels required to cut through these products. These ratings are currently being reviewed and the load ranges in the performance rankings will be changed to reflect the newly modified test protocol.
Trends in productsOne challenge that continues to be an industry-wide issue is the standardization of glove sizing. Besides the wide variation of hand sizes from person to person, an industry-wide size standard has not been established, meaning not all size 8 gloves have the same fit. Poor fits â€” tightness or bagginess through the palm area or fingers that are too long or short â€” can hamper dexterity.
Some newer products made by combining spandex with high-performance fibers improve the fit of hand protection while reducing the number of sizes needed. Use of these products provides cut and abrasion protection, as well as a high level of dexterity and conformability.
â€œPalm dippingâ€ with a variety of polymers can increase grip and allow breathability across the back of these gloves. Several newer yarn constructions offer reinforced high-performance yarns with spandex, or as a plated product to a covered spandex yarn, for the best of both worlds: high resistance to cutting hazards coupled with a high degree of conformability.
Seamless glove knitting machines with finer gauges, such as 15g, 13g or 10g, have become more prevalent, replacing previous demand for heavier, thicker 7g gloves. Some job hazards might require heavier gloves produced on the 7g machines, but many new composite yarn constructions were developed to offer a broader range of cut-resistant products where the ultra-high cut performance is not required.
Another trend gaining acceptance among glove users, especially in the meat and food processing area, are anti-microbial treatments, which can help to kill bacteria. There are many types of anti-microbial finishing processes, which vary greatly in durability.
Color is included in many yarn constructions as a way to hide dirt or indicate performance index level. It may also be used to indicate a specific area for a targeted performance level. Several food processing companies do not want gloves to cross-contaminate, so they use different colored gloves when handling different foods â€” one color for meat, one for vegetables, and one for breads.
Trends in safetyAs budgets tighten, getting the most out of cut protection is essential. The Bureau of Labor Statistics reports an average recordable hand injury costs approximately $6,000 per incident. Estimates from the industry, however, put the total cost of a recordable hand injury as high as $20,000, including costs associated with both medical and productivity losses.
The number of lost-time injuries due to finger and hand lacerations continues to decrease, according to BLS. Education and improvements in cut-resistant glove technology have been instrumental in lowering these injury rates.
Bottom lineThe key to success when purchasing hand cut protection is being informed, because the myriad options and claims can cause confusion. To evaluate the most appropriate hand protection product, many manufacturers will perform on-site evaluations with their distributors to assess specific hazards. Manufacturers will review desired features and discarded gloves for signs of premature wearing, while recommending the most appropriate glove selections for specific trial evaluations.
When considering the cut performance of a glove, make sure you get what you pay for. You also need to understand the individual cut value, not only the performance level for the glove product being considered. Additionally, keep in mind that while some initial glove costs might be higher, many other factors play a contributing role in the overall costs associated with protective apparel. Extra protection, longevity, and worker comfort should always be considered when selecting hand and arm protection.