Determining the shelf life of gloves shouldn't be a stretch
Answered by Nelson Schlatter, technical applications chemist, Ansell Healthcare, Red Bank, NJ.
Glove shelf life depends on how products are stored and on the materials used to manufacture them. Natural latex gloves have an approximate three-year shelf life, while gloves made of nitrile, Hycar, neoprene, PVC, urethane, PVA, EVOH, polyethylene and other synthetic coatings have a nominal five-year shelf life.
These guidelines may be conservative when gloves are properly stored. This is especially true of synthetic products designed for multiple uses, which have been stored for more than 10 years with no apparent damage. However, no glove manufacturer would be willing to guarantee a glove stored for such a long period.
While the Food and Drug Administration has not set any shelf-life guidelines for surgical and medical gloves, some manufacturers specify these products may be stored up to five years. The West Conshohocken, PA-based American Society for Testing and Materials is developing a protocol for estimating glove shelf life. Once this is established, FDA may change its policy and compile its own guidelines.
Manufacturer shelf-life guidelines are not applicable when the product package seal is broken, when gloves are removed from their original packaging or when they have been exposed to moisture. Shelf life also is reduced when gloves are exposed to ozone or ultraviolet light for extended periods or stored in areas with temperatures above 90° F.
In general, when gloves look normal, can be stretched without surface cracks, and can be pulled onto the hand without breaking or tearing, they probably will provide the level of protection they were designed to provide. Gloves that have deteriorated during storage will have definite signs of deterioration. They will tear easily when stressed and will develop a hard surface that cracks when stretched. The inside of powder-free gloves that do not have a separate donning layer may change from a tough polymer to a gooey substance.
As far as sterile gloves are concerned, the Denver-based Association of Operating Room Nurses, in its 1999 "Standards, Recommended Practices and Guidelines," recommended "packages be considered sterile unless damaged or opened." According to these guidelines, if older gloves appear to be useable, they also can be considered sterile as long as the packaging has not been damaged or opened.
To maximize the useful life of any type of gloves, the products should be stored in a cool, dark environment, shielded from ozone and UV light. This is especially important for natural rubber gloves, which are extremely susceptible to degradation from UV light, including the weak UV from fluorescent lamps, and ozone that may be generated by motors or other electrical equipment. Gloves always should be stored away from steam pipes, radiators and other heat sources.