MSDSs

Allergic Reactions to Latex Gloves

I. Introduction and Background

A. Federal Agencies Recognize a Health Problem

The Food and Drug Administration (FDA) has proposed amendments (expected to be ratified in the next few months) to its medical device regulations to address the burgeoning incidence of latex allergies amongst healthcare workers and their patients. The regulations will require specific labeling of all medical devices (including gloves) containing natural rubber latex (NRL) that may directly or indirectly contact human tissue. The regulations pertain to gloves classified as "medical gloves," gloves used by surgeons or for patient examination.

While the issue of FDA labeling compliance is not necessarily a concern for lab workers, these employees are nonetheless at risk of allergic response to latex gloves. Whether classified as "nonmedical, utility, industrial, protective, or general purpose" gloves outside of the FDA's purview, latex gloves are a potential hazard to any worker who must wear them on a regular basis.

Be aware that the FDA interpretation of "medical" gloves is not based on the wearer's/consumer's end use of the gloves (e.g., in a lab, cleaning your house, as a food server) but on the vendor's classification of the gloves as such. For example, if the gloves are advertised as medical gloves in the manufacturer's or distributor's supply catalogue, then they are officially medical gloves and you should be able to find a label to warn you of latex composition. For those lab workers who must contend with latex allergy, this notice is beneficial because you have prior purchasing information available to allow you to reject given, possibly irritating brands.

In conjunction with the FDA's Notice of a Proposed Rule, the National Institute for Occupational Safety and Health (NIOSH) issued an "Alert" entitled "Preventing Allergic Reactions to Natural Rubber Latex in the Workplace." See the NIOSH Home Page (http://www.cdc.gov/niosh/) for the text of this document. Much of the information in this ORS bulletin was taken from the "Alert."

B. History

There has been a dramatic increase in the occurrence of serious types of reactions to latex since the late 1980s. Estimates of incidence vary widely. The literature reports that anywhere from 5 to 15% of hospital workers suffer from this affliction. One to 6% of the general population experience this condition. Specific incidence rates for lab workers are not available but studies have shown that 11% of nonhealthcare workers exposed to latex at their jobs will also manifest symptoms of the allergy.

Those healthcare professionals following the rising trend attribute the increase in disease prevalence to two major factors.

• Between 1987 and 1992, both the Centers for Disease Control and Prevention (CDC) and the Occupational Safety and Health Administration (OSHA) instituted the application of universal precautions in occupations with the potential for transmission of bloodborne pathogens. The incidence rates for diseases such as Hepatitis and AIDS warranted vigilant measures for worker protection; gloves are a mainstay defense for controlling the transfer of infectious agents through contact with human blood and other human-derived products.
• Increased demand for gloves has resulted in a concomitant rise in the glove supplies on the market. Some manufacturers made changes in their production processes to allow greater volumes of product to be generated to meet the demand. For some companies, the quick turnover of glove stocks has led to process modifications such as shorter wash times and shorter shelf times, both factors that can augment the potential for allergic response.

II. Definition of Latex

A. Natural vs. Synthetic Latex: Clarification of the Terminology

Natural rubber latex (NRL) is a milky fluid derived from the Hevea brasiliensis tropical rubber tree. The raw agricultural material can be processed by two different methods.

• The NRL manufacturing process involves the use of the tree-sourced fluid in a concentrated form. Products are made by dipping, extruding, or coating the concentrated milk. This is the process by which gloves (and also catheters and condoms) have typically been made.
• Alternatively, there exists a dry natural rubber (DNR) curing/manufacturing process. The liquid from the tree is coagulated and dried or milled into sheets. Products are fabricated by compression molding or extrusion of the sheets. The sheets may also be converted into a dipping bath. Gloves containing "dry rubber" are equally likely to cause irritation as gloves made by the NRL method.

Synthetic latex is an emulsion of synthetic rubbers and plastics to which natural rubber latex may or may not be added. As pertains to latex allergy, a glove that contains any natural rubber latex may cause a reaction. Synthetic gloves are only truly "synthetic" when they include NO NRL or dry rubber in their formulations.

B. Hypoallergenic Gloves

Gloves described as "hypoallergenic" latex gloves do NOT reduce the risk of latex allergy. The adjective "hypoallergenic" refers to reduced quantities of chemical additives in the latex. These gloves may alleviate irritant reactions (from chemical sensitivity) but not "true" latex allergy. This term is based on results of the modified (human) Draize test which is not effective for predicting individual susceptibility to protein allergy.

III. Symptoms of Latex Allergy

There are three types of reactions to latex gloves.

The health consequences of exposure can be significant for those workers allergic to latex. Some individuals become so sensitive that they can no longer use any latex-containing products or be present in an environment where latex particles are present in the air. The IgE-mediated sensitivities may cause life-threatening reactions in some victims.

IV. Routes of Exposure

For those individuals afflicted with hypersensitivity, the routes of exposure go beyond skin contact. IgE-mediated reactions may additionally occur from exposure to mucosa (e.g., nasal cavity, genitourinary tract), parenteral invasion (intravenous, subcutaneous, intramuscular--as during surgery), and by inhalation. The threshold amount of protein and extent of latex exposure time that activates a sensitization or allergic reaction are unknown. The risk of progression from skin rash to more serious reactions is also unknown.

The proteins associated with latex allergies adhere to the powder used in some gloves. When powdered gloves are worn, more latex protein reaches the skin. The removal of gloves can release protein/powder particles into the air, where they can be inhaled or come into contact with mucosa.

V. Those at Greater Risk

Atopic individuals (i.e., those persons with a tendency to have numerous allergies) are predisposed to this ailment. Latex allergy is particularly associated with allergies to certain foods, especially avocados, potatoes, bananas, tomatoes, chestnuts, kiwi fruit, and papaya. Persons with congenital defects of the spine, primarily spina bifida, are at increased risk of latex allergy, probably due to the multiple operations (and, thus, exposures to latex) they must endure.

VI. Recommendations For Prevention

The only effective treatment for a worker who has been sensitized to latex is avoidance. Exposure to the allergenic proteins must be reduced for the victim to maintain a healthy state. Certain medications may reduce allergy symptoms but relief is minimal. Avoidance, while certainly difficult and often impractical, is absolutely the best approach to protecting the afflicted person.

Latex allergy can be prevented if employees are spared undue exposures to latex. The following steps illustrate feasible approaches to protecting reaction-prone workers.

1. Provide synthetic latex, nonlatex, or nonpowdered gloves whenever possible.
2. If available from your chosen vendor, select latex gloves with reduced protein allergen content.

• Many reputable glove manufacturing firms are actively pursuing research to improve the safety of their gloves. Although there is no well-accepted standardized test available to screen gloves for allergy-causing proteins, total protein content data serve as useful indicators of probable antigen retention. Total protein tests of different brands of commercially available gloves reveal a huge range of concentrations depending on the manufacturer.

3. Practice good housekeeping to remove latex-containing dust from the workplace (e.g., by wet-wiping lab benches and other work surfaces).
4. Raise awareness of latex allergy issues with colleagues and lab staff.
5. Be alert to detecting the symptoms in yourself or your colleagues and respond by eliminating NRL products from your lab.
6. Do NOT use oil-based hand creams or lotions unless they have been shown empirically to reduce latex-related problems.
7. Wash your hands with a mild soap after removing gloves and dry them thoroughly, especially between folds of skin where moisture may collect.
8. Consult the Office of Risk Management (1-5582) if symptoms of latex allergy become apparent. Request a medical evaluation at the workers' compensation service provider for your campus and suspend all further contact with latex until you have been evaluated and/or diagnosed.
9. Consider wearing a medical alert bracelet should you ever need emergency medical treatment.

VII. Hope For the Future

Major glove supply companies such as Ansell-Edmont and Best Manufacturing are devoting significant resources to reducing the latex protein allergen content of their latex glove product lines. This research grew out of earlier work to remove chemical residues (irritating accelerators and antioxidants) from gloves. The same solutions used before have potential for application in achieving the new goal.

Leaching is a process used to extract excess chemicals and has been shown to be successful in removing protein allergens as well. This procedure offers hope for eventual widespread control of the stimuli that initiate latex allergy.

• Pre-Oven Leaching: removes residual calcium nitrate and some natural rubber proteins.
• Post-Oven Leaching: removes natural rubber proteins as the gloves are continually washed with replenished hot water.
• Chlorination: further removes natural rubber proteins as gloves are washed in chlorinated water.

The American Latex Allergy Association offers latex-free alternatives when you click on "Latex Alternatives." Information about glove suppliers can be found under Medical Products. At present, there are no data available concerning the differences between permeation rates and breakthrough times of NRL and synthetic gloves. It has been a long-held industry assumption (correct or not?) that NRL provides superior protection against infectious agents due to its tear resistance, elasticity, and tactile sensory characteristics. That belief cannot be supported concretely at this time.

VIII. For Further Information

Ansell Healthcare Division. Recognizing the Problem, Facing the Challenges. Ansell Healthcare Division (1997).

Food and Drug Administration. Latex-containing Devices; User Labeling. Federal Register, Vol. 61, 122 (June 24, 1996).

Halsey, John F. "IH Has Valuable Role in Latex Allergy Dilemma." The Synergist (AIHA, June/July 1997): 51-52.

National Institute for Occupational Safety and Health. NIOSH ALERT: Preventing Allergic Reactions to Natural Rubber Latex in the Workplace. DHHS (NIOSH) Publication No. 97-135 (June, 1997).

-------. NIOSH ALERT on Work-Related Latex Allergy Recommends Steps to Reduce Exposures. HHS Press Release (June, 1997).

Internal ORS Links: What's New | Emergency Response | Administration | Biological Safety | Chemical Safety | Hazard Communication | Laboratory Safety | New to NU? | Radiation Safety

External ORS Links: Northwestern Home | Vice President for Research | Big 10 EH&S Links | Risk Management | Employee Safety Handbook

ORS - Evanston • 2145 Sheridan Road • Tech NG71 • Evanston, IL 60208
ORS - Chicago • 303 E. Chicago Avenue • Ward B106 W223 • Chicago, IL 60611
Phone 847/491-5581 or 312/503-8300 • FAX 847/467-2797 or 312/503-0547
e-mail researchsafety@northwestern.edu
Last Revision 05/16/2007
© 2007 Northwestern University. World Wide Web Disclaimer and University Policy Statements.