Although rubber gloves provide good protection from a wide variety of hazards, for a significant part of the workforce, these gloves pose problems of their own: allergic reactions. Proteins in natural latex or accelerators used in manufacturing synthetic rubber gloves can cause these reactions, which vary from mild skin irritation to contact dermatitis to life-threatening anaphylactic shock. The degree of sensitivity can increase over time. In many cases, the reactions can become sufficiently severe to prohibit an employee from using gloves, effectively ending their ability to work in certain industries or occupations.
Allergic reactions to latex that emerged just over a decade ago in nearly epidemic proportions have been well-documented and studied. We know a lot more now than we did 10 years ago about the cause of latex protein allergy; government and industry have taken significant action to reduce its human health impact. We have also learned something else more recently - that debilitating allergic reactions are caused by more than just latex. We now know that chemicals used to manufacture synthetic gloves can also cause allergic reactions.
General Skin-Related Allergies
The American Academy of Allergy Asthma and Immunology lists the following allergy statistics for people who live in the U.S.:
- Atopic dermatitis is one of the most common skin diseases and the estimated prevalence in the U.S. is 9 percent.
- Healthcare provider visits for contact dermatitis and other eczemas are 7 million per year.
- Estimates indicate that between 2.85 and 17.1 million people in the United States are allergic to natural rubber latex proteins.
Anaphylaxis is the worst type of allergic reaction from latex. It is life-threatening and must be treated immediately. Latex proteins from gloves have been shown to cause anaphylaxis in severely sensitized individuals. Latex reactions can occur from inhalation or skin exposure, but can also occur through ingestion of food that has been touched by latex. Studies indicate 1 percent to six percent of the general population is allergic to latex proteins. A variety of symptoms may occur, such as rhinitis, conjunctivitis, hives, itching, sneezing, sore throat, asthma or dermatitis.
The consensus is that the reaction to latex gloves is from natural rubber proteins, but no one has found which protein is ultimately responsible for the sensitization. It appears that several different proteins may be involved, and that different proteins may cause different reactions.
Different assays to test patients for allergenicity to latex have been developed, but to date no real progress has been made on a method to desensitize latex allergy sufferers. You cannot perform skin-prick testing to diagnose latex allergy. It is very dangerous and has caused anaphylaxis in experimental trials. The prognosis, even 12 years after the first cases, remains avoidance.
Several excellent reports are available that further describe the impact of latex on human health, including OSHA's Technical Information Bulletin - Potential for Allergy to Natural Rubber Latex Gloves and other Natural Rubber Products, published April 12, 1999 and the NIOSH 1997 Alert, "Preventing Allergic Reactions to Natural Rubber Latex in the Workplace" (NIOSH publication 97-135.)
Low Proteins or Deproteinized Latex
The logical step after understanding the impact of latex on human health was to lower the amount of sensitizing proteins in disposable latex gloves. Most manufacturers of latex gloves have taken steps to lower the protein level by leaching, aging, chlorination or through enzyme treatment. There are gloves made from completely deproteinized latex.
No studies have actually been performed to determine if deproteinized latex is safe for those who are allergic to latex, however some studies have shown that the incidence of reactions has dropped in places where the change is made to powder-free, low-protein, latex gloves. The American Academy of Allergy, Asthma and Immunology advises that when latex gloves are used they should be low-allergen and powder-free. NIOSH also recommends reduced-protein, powder-free gloves.
But, with the potential for allergic reaction still possible, even with reduced-protein natural rubber latex gloves, is latex still the best option? There are completely latex-free alternatives that must be considered.
Non-Latex Glove Alternatives
Synthetic polymers such as vinyl and nitrile have emerged as the alternative materials for new gloves. Gloves made from these polymers do not contain any natural rubber latex, and therefore can be used by workers with latex allergy.
Nitrile gloves have excellent protection qualities, especially when handling petroleum-based products. Recent studies have shown that nitrile gloves have an even lower failure rate than natural rubber latex gloves in side-by-side comparison of simulated industrial use. Nitrile has become a very favorable alternative to latex, however, until recently even nitrile gloves caused allergic reactions in a small number of workers.
Type IV Reactions: Accelerators
Allergic reactions to synthetic gloves became apparent as non-latex glove use became more prevalent. In some cases, reactions continued even after latex use was discontinued. It was discovered that chemical additives, called accelerators, which are necessary in the manufacture of synthetic gloves, could cause some types of allergic reactions.
Most elastomeric gloves contain accelerators. Accelerators are used in natural rubber latex, nitrile and neoprene gloves to promote cross linking and polymer formation to make stronger, more resilient gloves. The type of allergic reaction to accelerators is called a Type IV reaction, and is characterized by severe contact dermatitis that may resemble a poison oak reaction. This is a localized reaction that only occurs in areas where the glove touched the skin and may appear much later, after the glove has been removed.
Until recently, all elastomeric gloves were made using accelerators. However, new ground was broken when one major glove manufacturer developed a patented (pending) formulation for making a nitrile glove that is accelerator-free. The glove has no latex proteins and no accelerators, and therefore is free of the causative agents for both Type I and Type IV allergic reactions. This glove, invented by Best Manufacturing, is known as the N-DEX® Free and is an extension of the N-DEX® line. It has received a FDA 510K registration as a Class 2 medical device, is the only disposable rubber glove that can be labeled "non-allergenic," and represents the latest innovation in the ongoing effort by glove manufacturers to provide effective barrier protection without causing allergic reactions.
The Last Word
Workers that are allergic to latex and accelerators have had their livelihoods threatened. Remember, sensitivity to these allergens can build up over time, so that reactions may occur many years into a person's career. For those workers, latex-free, accelerator-free gloves could be the answer they've been waiting for. By using this glove, sensitized workers can remain in their chosen occupation without suffering from painful and debilitating skin allergies.
About the Author: Donald F. Groce, Best Manufacturing, is a technical product specialist and a research chemist. Before joining Best, he worked for the U.S. Centers for Disease Control and Prevention on chemical toxicology studies that included the Agent Orange Study. He is a noted speaker and expert on a variety of occupational and workplace hazards, including latex allergies and chemical exposure-related illnesses.
The N-DEX® Free can be seen at the National Safety Congress and Exposition in San Diego, Oct. 7-9, by visiting Best Manufacturing at Booth 4136. Samples are available by calling (800) 241-0323 or visiting www.bestglove.com.