Medical Device & Diagnostic Industry Magazine
MDDI Article Index

Wava Truscott

In the medical device and diagnostic industry, gloves routinely serve a dual purpose: protection of the employees and of the products they manufacture. Glove selection must not only be based on their ability to protect employees from processing agents used in manufacturing and microorganisms in laboratory environments, but the choice must also take into account the very real problem of potential reactions related to wearing the gloves themselves. In addition, the chosen gloves must protect work-in-progress from particles, skin oils, extractable chemicals, microorganisms, endotoxins, and any other substances defined as contaminants by product requirements; they must not, themselves, contribute such contaminants to the product. And, finally, to maintain their role as a safeguard throughout their time in use, gloves must be durable. This article reviews the key criteria for the selection of gloves for manufacturing personnel and addresses concerns related to their use and disposal. Also discussed is the real concern that glove use may affect product performance.

The importance of fit in glove selection depends on the task being performed. Factors to consider when evaluating gloves include the following:

To assess the potential degradative properties of a particular lotion, the following simple experiment may be performed. Cut two equal 0.25- to 2-in. strips from the palm or back surface of a glove, and then stretch and secure the strips to approximately 3 times their length. Coat one with the lotion in question, leaving the other uncoated as a control. After 30 minutes, release the strips and place them side by side. If the lotion-treated sample has enlarged either in length or width, and breaks more easily than the control, the material's mechanical stability has been degraded and the lotion is unacceptable.

Chemical compatibility. Gloves should also be evaluated for chemical compatibility with the various solutions that the employees will handle. Evaluations should be performed with the correct chemical concentration, contact (splash or immersion), and length of exposure to ensure relevancy. Indicators of degradation include glove softening, tackiness, brittleness, finger elongation (creep), increased transparency, loss of strength, and loss of elasticity. (Hazardous chemicals require sophisticated methods of permeation analysis, and such tests should only be undertaken by individuals trained for such procedures.) If the glove degrades quickly during routine chemical contact, it will be necessary for workers to change gloves frequently, wear double gloves, decrease chemical contact time, or choose a different glove material.

Staining and discoloration. A discolored glove may or may not be a symptom of glove degradation. Most amber or brown discoloration that is apparent when gloves are removed from their container is a result of overchlorination, excessive heat, overdrying, or contact with copper, brass, iron, or other interactive metals during manufacturing. Such "browning" may or may not indicate a loss of material strength. A variation in the intensity of yellow from one natural rubber glove to another may be a function of the trees used in the respective batch of latex or a very mild case of the browning detailed above. Translucency is caused by insufficient leaching or an excessive use of defoaming agents, emulsifiers, or surfactants during glove manufacture.

Hazing or whitish regions on unused gloves indicate areas of ozone attack. Ozone is created by energy-generating sources such as fluorescent and ultraviolet lights, x-ray machines, heavy-duty fans, and similar equipment. In its attempt to become more stable, ozone breaks the chemical bonds between elastomer chains in latex and most synthetic gloves, leaving the material weaker. This activity begins in creases and folds where the glove material is most stressed, resulting in a line of holes or cracks. Ozone will attack only unwrapped gloves and those enclosed in packages containing excessive amounts of air (available oxygen); therefore, unless the glove manufacturer erred significantly in the addition of antiozonates or exposed the gloves to ozone prior to packaging, this phenomenon can largely be controlled in-house by paying careful attention to glove storage conditions.

If discoloration occurs during use, it is termed staining and may be caused by chemicals from the glove reacting with chemicals secreted by the wearer. For example, carbamate, the least sensitizing of the accelerators used in latex processing, reacts with lactic and uric acid from human perspiration to cause an amber or brown stain. Nicotine from the skin of smokers turns gloves brown, as do copper and iron, excreted to varying degrees through the skin by healthy individuals. Some illnesses and the use of specific medications may also result in glove staining. Gloves with color additives may mask much of the discoloration.