Q&A - Hand protection
What are some â€œrules of thumbâ€ to help determine if a glove has any shelf-life left?
ANSWERS:Any shelf-life remaining depends on how long the gloves were stored and the materials used. Natural latex gloves have a three-year shelf-life, with a two-year shelf-life for those made from fabrics (cotton, nylon, polyester, Spectra and KevlarÂ®).
The following materials have a five-year shelf-life: natural latex, nitrile latex, HycarÂ®, neoprene, PVC, urethane, PVA, EVOH, polyethylene and other synthetic coatings.
These guidelines are void if products have broken packaging seals, are removed from original packaging, exposed to moisture, exposed to ultraviolet light for an extended time, exposed to temperatures over 90 degrees Fahrenheit, or have ozone exposure.
Paul McMorrow, Quality Assurance Manager, Ansell Healthcare
Determining a gloveâ€™s shelf-life depends on various factors. What type of polymer is the product? Is the product unsupported or supported? Is it a chemical-resistant glove or not? Is the product a disposable â€” the least â€œshelf-lifeâ€ products?
There is no real standard by which all glove manufacturers abide. End-users should deal with manufacturers that will stand behind their products.
Craig Wagner, President, Global Glove & Safety Manufacturing
Cut- and puncture-resistant gloves are made with aramid fibers. These gloves should not be exposed for prolonged periods of time to sunlight. The UV rays diminish the performance of the aramid fibers and, thus, the cut and puncture resistance of the gloves. Gloves should be stored away from any windows or outside sources of light.
To determine if the glove has been compromised, check the color. A normal aramid-based glove is bright yellow. If the glove has turned pale and gold-colored, this is an indication that it may have lost some of its protective properties.
Matt Keenan, Sales Manager, TurtleSkin Gloves
Unsupported disposable styles are the predominate glove styles with a shelf-life. Leather, cotton, supported and string-knit styles have extended shelf-life when properly stored.
Shelf-life will vary depending on the specific polymer type and how each is treated (powder, powder-free, polymer-coated, chlorinated) and stored.
Latex disposable styles â€“ One advantage of chlorinated gloves over polymer-coated gloves is the greater removal of latex proteins that cause allergic reactions. A limiting factor is that powder-free double-chlorinated (inside/outside) styles generally have a shelf-life of about one year before the gloves start becoming brittle and susceptible to ripping. Contrast this with powdered versions that have been chlorinated on one side, which exhibit a three-year shelf-life.
Polymer-coated gloves do not break down as quickly because they are not introduced to chlorine during the manufacturing process. Powder-free polymer-coated options have a shelf-life of three years and powdered versions five years.
Vinyl disposable styles â€“ As long as extreme temperatures, large humidity variances and prolonged exposure to light is avoided, powder-free and powdered vinyl should have a shelf-life of longer than five years.
Nitrile disposable styles â€“ Powder-free, three years. Powdered, five years.
Larry Garner, Chief Marketing Officer, MCR Safety
Storage location and temperature may have an impact on a gloveâ€™s shelf-life, so it is important to follow manufacturersâ€™ suggested storage temperatures. Beyond contacting the manufacturer to determine when the gloves were produced, visually inspect the gloves for signs of discoloration, often an early indicator they may be past their prime.
Next, gently stretch and bend the gloves to look for cracks or fissures. In a supported glove, check to ensure the polymer coating is not pulling away from the woven lining. Submerge fully coated liquid-proof gloves in a bucket of water to check for leaks or signs of pinholes.
Mike Gompers, QSSP, Product Development Manager for cut-resistant and general purpose gloves, Best Manufacturing
If the gloves have not been put in service, the shelf-life will vary depending on the manufacturerâ€™s recommendation and the glove material. Shelf-life is an important consideration for natural rubber and, to a slightly lesser extent, for synthetic gloves.
Excessive temperatures, humidity and UV radiation have an adverse effect on natural rubber and synthetics, and will shorten the life of the glove. Glove manufacturers recommend that gloves be stored in even temperature and humidity conditions, and that they be kept in their cases to protect them from both sunlight and artificial light.
Typically, liquid-proof gloves made from natural materials such as natural rubber will degrade faster than those made from synthetic materials because they contain proteins that will break down. Provided glove storage recommendations are met, natural rubber gloves should have a shelf-life of two years. Other materials should last up to five years without problem.
If the gloves are in service, typical signs of overexposure include swelling, sagging, discoloration, holes and cracking.
Lisa Rizzo and Dan Ledwig, Product Managers, Hand Protection, North Safety Products
Every major glove manufacturer recommends that their products be â€œstored in cool, dry environments in the original bags and shipping boxes,â€ or something to that effect. Heat, humidity and UV light are three factors that work to degrade all glove materials. Look for discoloration, cracking, mold, mildew and bad odors to determine if gloves are past their â€œshelf-lifeâ€ time. Discard and replace any gloves that show any of these signs.
Bill Soellner, Product Specialist, Perfect Fit Glove, Bacou-Dalloz