|Please Note: This Technical Information Bulletin (TIB) is currently under review by OSHA. OSHA is reviewing the medical literature and studies. Among other issues, OSHA is assessing the accuracy of the TIB’s use of dissimilar terms interchangeably, and examining the TIB’s reliance on protein levels rather than allergen level as the relevant factor for determining the allergenicity of natural rubber latex gloves. This TIB will be revised as appropriate. The updated TIB will be available soon.|
|U.S. Department of Labor||Occupational Safety and Health Administration
Washington, D.C. 20210
Reply to the Attention of:
|APR 12 1999|
|MEMORANDUM FOR:||REGIONAL ADMINISTRATORS|
R. DAVIS LAYNE
Deputy Assistant Secretary
|FROM:||STEVEN F. WITT
Directorate of Technical Support
|SUBJECT:||Technical Information Bulletin*: Potential for Allergy to Natural Rubber Latex Gloves and other Natural Rubber Products|
This technical information bulletin is intended to alert field personnel to the potential for allergic reactions in some individuals using natural rubber latex (NRL) products, particularly gloves, in the workplace setting. Natural rubber is utilized in a variety of products including gloves, airways, airway masks, medication vial tops, anesthesia bags, various catheters, supplies for intravenous use, dental dams, balloons, and other products.(1,2,3) NRL glove use in the health care setting has risen dramatically since about 1987, due to the increased threat of contracting HIV, hepatitis B, and other infectious agents in the course of delivering health care to patients and the need for barrier protection.(1,4) Thus, the frequency of exposure to NRL among health care and other workers has increased.
NRL products are also used to provide barrier protection from some chemicals and other agents in health care and other environments. (NOTE: While NRL gloves are useful for certain purposes, they are not universally suitable. The properties of a glove material for a specific use must be determined in advance of use. Gloves appropriate for protection from the particular chemical or agent must be used.) NRL gloves are also used to prevent contamination of products in some workplaces (e.g., electronics and drug manufacturing). Natural rubber articles are manufactured in some workplaces (e.g., manufacturers of medical gloves, industrial gloves, balloons, rubber bands, boots and shoes, and many other products).
With more widespread use of NRL gloves, there has been an increase in reported NRL allergies, among patients as well as among workers, notably health care workers. Rarely, these allergies can be fatal. In addition to reports from the dermatology, allergy, and pulmonary literature of severe skin and respiratory symptoms, life threatening reactions to NRL products have been noted in pediatric patients with spina bifida who had undergone numerous surgical procedures, resulting in repeated NRL exposure.(5,6,7) In addition, the US Food and Drug Administration (FDA) received reports of numerous severe allergic reactions, including several deaths, associated with exposure to NRL enema cuffs in providing care to sensitized patients.(8)
NRL is manufactured from a variety of plants, but mainly the rubber tree, Hevea brasiliensis. The milky fluid from the tree contains variable amounts of proteins which may be absorbed through the skin or inhaled and cause allergic reaction in susceptible workers. NRL contains many proteins. A number of these proteins, such as hevamine, hevein, and rubber elongation factor (REF), may initiate allergic reactions to NRL. Studies have indicated that corn starch powder, added to gloves to facilitate donning and removal, can serve as a carrier for the allergenic proteins from the NRL.(2,3,9)
In addition, gloves, including those made from NRL as well as some other materials, may contain chemical accelerators such as thiuram, carbamates, and benzothiazoles to which a worker may also develop sensitization, resulting in allergic contact dermatitis. Antioxidants, biocides, soaps, and other chemicals used in the processing of NRL products may contribute to sensitization as well.
In 1987 the Centers for Disease Control and Prevention (CDC) recommended universal precautions, the concept that blood and certain body fluids from all individuals should be approached as if potentially infectious. The use of barrier protection was subsequently required by OSHA’s bloodborne pathogens standard. The increased use of latex gloves in a variety of settings greatly increased the exposure of health care workers to NRL.(1,4)
The two major routes of exposure include dermal exposure and inhalational exposure. NRL protein absorption has been reported to be enhanced when perspiration collects under latex clothing articles.(10) Exposure may also occur by the respiratory route, particularly when glove powder acts as a carrier for NRL protein which becomes airborne when the gloves are donned or removed.(2,3,9) Some investigations have indicated that powder free gloves with reduced protein content reduce risk of development of NRL allergy.(11) Some questions regarding powder free glove shelf life and ease of use have arisen and are being addressed. Importantly, only non-NRL gloves must be used by those workers who are allergic to NRL.
The majority of health care workers are able to use NRL products to care for most patients. Variations exist in the reported prevalence of NRL allergy. This variation is probably due to different levels of exposure and methods of estimating latex sensitization or allergy. Nevertheless, prevalence studies indicate that from around 6% to 17% of the exposed health care workforce is allergic to NRL.(5,12,13,14,15) In a survey of active duty dental officers in the U.S. Army, the prevalence of allergic symptoms correlated with NRL use was reported to be 13.7%.(16) An investigation of dental workers using NRL skin prick testing at two consecutive American Dental Association meetings revealed allergic responses in 9.1–9.7% of dental hygienists and assistants, although dentists showed a lower rate of 5.1–6.7%.(17) The general population exhibits a lower rate of NRL sensitization (approximately 1 to 6%).(18,19) These prevalence statistics are based on seroprevalence as well as skin test positivity and/or allergic manifestations and do not refer to the more serious anaphylactic response, which is rare but potentially life threatening in some individuals.
In addition to dentists, health care workers reported to have especially high risks include operating room personnel consistently exposed to NRL (i.e., operating room nurses, physicians, and technicians).(3,18) NRL allergy has also been reported in greenhouse workers,(20) hairdressers,(21) doll manufacturing workers,(22) and workers in a glove manufacturing plant,(23) and may pose a risk to others as well.(24)
Use of natural rubber products may result in several varieties of reactions (see table). These reactions include irritant and several types of allergic reactions. They can vary from localized redness and rash to nasal, sinus, and eye symptoms to asthmatic manifestations including cough, wheeze, shortness of breath, and chest tightness; and rarely, systemic reactions with swelling of the face, lips, and airways that may progress rapidly to shock and, potentially, death.
When gloves are associated with skin lesions, the most common reaction is irritant contact dermatitis. Irritant contact dermatitis may be due to direct irritation from gloves or glove powder, but may also be due to other causes, such as irritation from soaps or detergents, other chemicals, or incomplete hand drying. Irritant contact dermatitis presents as dried, cracked, split skin. Although irritant contact dermatitis is not in itself an allergic reaction, the breaking of the intact skin barrier due to these lesions may afford a pathway for latex proteins to gain access, and thus promote development of allergy.(25)
The second type of reaction that may be associated with glove use is allergic contact dermatitis (also known as type IV delayed hypersensitivity or allergic contact sensitivity). When glove use has been associated with this reaction, it appears to be due to the chemicals used in processing NRL or other glove materials. The allergic contact dermatitis has an appearance similar to the typical poison ivy reaction, with blistering, itching, crusting, oozing lesions. Also, like poison ivy, this dermatitis may appear a day or two after the use of gloves or exposure to other sources of chemical sensitizers.
The third and potentially most serious type of reaction sometimes associated with glove use is a true IgE/histamine-mediated allergy (also called immediate or type I hypersensitivity) to glove protein [in the case of NRL allergy, to NRL protein(s)]. This type of reaction can involve local or systemic symptoms. Localized symptoms include contact urticaria (hives) which appear in the area where contact occurred (in the case of gloves, the hands), but which can spread beyond that area and become generalized. More generalized reactions include allergic rhinoconjunctivitis and asthma. The presence of allergic manifestations to NRL indicates an increased risk for anaphylaxis, a rare but serious reaction experienced by some individuals who have developed an allergy to certain proteins (e.g., insect stings, natural rubber, penicillin). This type I reaction can occur within seconds to minutes of exposure to the allergen (in the case of NRL, to natural rubber proteins) either by touching a product with the allergen (e.g., gloves) or by inhaling the allergen (e.g., powder to which natural rubber proteins from gloves have adsorbed). When such a reaction occurs, it can progress rapidly from swelling of the lips and airways to shortness of breath, and may progress to shock and death, sometimes within minutes. While any of these signs and symptoms may be the first indication of allergy, in many workers with continued exposure to the allergen (in the case of NRL allergy, to natural rubber proteins), there is progression from skin (contact urticaria) to respiratory symptoms over a period of months to years. Some studies indicate that individuals with latex allergy are more likely than latex non-allergic persons to be atopic (have an increased immune response to some common allergens, with symptoms such as asthma or eczema).(26) Once NRL allergy occurs, allergic individuals continue to experience symptoms, which have included life-threatening reactions, not only on exposure to NRL in the workplace but also upon receiving or accompanying a family member receiving health care services at inpatient as well as office-based settings. In addition, such reactions have occurred on exposure to consumer goods such as balloons, condoms, and other products. Moreover, some affected individuals continue to experience asthmatic symptoms even without contact with NRL. Therefore, development of allergy to NRL in an individual has lifestyle implications beyond the workplace.
Recommended Strategies — Risk Reduction
It is of primary importance that barrier protection be used when hands would otherwise contact infectious materials or hazardous chemicals. OSHA’s bloodborne pathogens standard requires that gloves be worn when it is reasonably anticipated that hand contact may occur with blood, other potentially infectious materials, mucous membranes, non-intact skin, or contaminated items or surfaces, as well as when performing most vascular access procedures [29 CFR 1920.1030, paragraph (d)(3)(ix)]. NRL is a glove material that has been used in the health care environment for barrier protection for a number of years. In response to reported NRL allergy in some patients and health care workers, measures have been recommended to reduce the risk of NRL allergy in workers.
Primary prevention involves reducing potential development of allergy by reducing unnecessary exposure to NRL proteins for all workers. Food service workers or gardeners, for example, do not need to use NRL gloves for food handling or gardening purposes. Gloves made of NRL as well as synthetic materials have been cleared for marketing as medical gloves by the FDA and can be used effectively for barrier protection against bloodborne pathogens. General administrative procedures** that an institution can follow to reduce worker exposure to NRL proteins include:
Use of powder free gloves has been shown to reduce the dissemination of NRL proteins into the environment and decrease the likelihood of reactions by both the inhalation and dermal routes.(2,27) Appropriate work practices when wearing hand protective equipment, including NRL gloves, include avoidance of contact with other body areas such as the eyes or face. Handwashing after glove removal is required by OSHA’s Bloodborne Pathogens Standard [paragraph (d)(2)(v)] and helps to minimize powder and/or NRL remaining in contact with the skin. Thorough clean-up of any residual powder in the workplace with appropriate vacuum filters will decrease employees’ exposure as well.
Since the reason for wearing gloves is to provide barrier protection from hazardous substances, substitute materials must maintain an adequate barrier protection and be appropriate for the hazard. At a minimum, gloves made from NRL or other materials and used for a medical purpose should be labeled as medical gloves. Such gloves must meet the FDA criteria for marketing, manufacturing, and testing of medical gloves. The Health Industry Manufacturers Association (HIMA), in conjunction with the FDA, has proposed general guidelines for use of medical gloves with some recommendations for those individuals who are allergic to natural rubber.(28)
One institution has reported that a coordinated effort to identify NRL sensitive individuals and reduce the use of “high allergenic” natural rubber latex gloves substantially reduced aeroallergen levels and costs.(4) Other investigators have reported that some NRL allergic workers have been able to work wearing nonlatex gloves when their coworkers wore powder free latex gloves.(29)
Effective September 30, 1998, the FDA requires labeling statements for medical devices which contain natural rubber and prohibits the use of the word “hypoallergenic” to describe such products.(8) NRL gloves with a reduced level of chemical accelerators must be labeled to eliminate confusion associated with the “hypoallergenic” claim and to provide more specific information to the user. Some NRL gloves and other devices produced before the effective date of the FDA regulation may not carry the NRL labeling or may be labeled “hypoallergenic”. Such products may still be in use in some facilities. It should be noted that such products should not be presumed to be NRL free. The hypoallergenic claim referred to the chemical additives, and such gloves may be powder free; however, they contain the NRL proteins to which NRL allergic workers react.(30) The FDA is currently exploring options for reducing exposure to NRL proteins and powder. It is important to note that these FDA regulations do not apply to non-medical devices, including utility gloves.
Recommended Worker Evaluation and Management
The administrative procedures outline above may not be sufficient to protect all individuals who have already developed NRL allergy. The American College of Allergy, Asthma, and Immunology has suggested that “safe zones” (areas in which non-NRL products are used and NRL proteins have been thoroughly removed from the environment) may be needed to protect those workers who are already sensitized to NRL.(5) Health care facilities should develop policies and procedures for reducing the risk of NRL allergies in the workplace. Prudent risk reduction strategy involves an initial survey and assessment, with a coordinated effort to identify and catalogue all NRL products used in the workplace. An ongoing program, involving close coordination with resource and materials management staff, should be established to monitor the NRL content of incoming products so that management staff can be prepared to choose appropriate products for offering non-NRL alternatives to control NRL exposure as well as for creating NRL safe zones.(2) Mechanisms for reporting and managing cases should be in place.
It is not possible, at present, to determine which workers will become allergic to NRL proteins, the extent of an individual worker’s reaction, or the length of time required for such allergic reactions to develop.(3) It is also not possible, at present, to predict who will progress from local contact urticaria to the more dangerous allergic reactions, nor when this may occur. (2,3) Laboratory and clinical evidence indicates that an association exists between allergy to natural rubber proteins and allergy to certain foods and plants (e.g., avocado, banana, kiwi, chestnut)(31) and some aeroallergens (e.g., pollens, grasses).(32) A history of multiple surgeries has also been reported to be a risk factor for NRL allergy.(2,5) In some institutions, periodic screening questionnaires for symptoms of NRL allergy in workers with current or past history of significant NRL exposure (e.g., surgical personnel) have been useful for ascertaining reaction rates and managing those individuals experiencing reactions.(3,5,30) A medical evaluation of hand dermatitis, by a physician experienced in dermatologic diagnoses, is essential for taking preventive steps and assuring effective therapeutic measures. Evaluation of signs/symptoms associated with latex allergy should be accomplished under the direction of a physician with expertise in NRL allergy, with additional medical testing and treatment made available if indicated.
Provision of latex-free procedure trays and crash carts for treatment of natural rubber allergic individuals has been recommended.(5) Although the fundamentals of emergency response (i.e., assuring airway, breathing, and circulation) remain of primary importance should a worker develop symptoms (including those caused by NRL allergy) requiring resuscitation, these situations should be anticipated in the workplace and provision of immediate access to non-natural rubber containing equipment considered.
Investigation continues into various aspects of NRL allergy; our understanding of some issues continues to evolve. Meanwhile, workers and workplaces need to be aware of the present state of knowledge regarding NRL allergy and methods of protection. Workers should be advised of symptoms of NRL allergy as well as primary and secondary preventive measures for decreasing the risk of NRL allergy development and NRL allergic reactions in workers who are allergic.
The National Institute for Occupational Safety and Health (NIOSH) published a 1997 Alert titled “Preventing Allergic Reactions to Natural Rubber Latex in the Workplace” (NIOSH publication number 97-135). NIOSH can be reached by calling 1-800-35-NIOSH (800-356-4674).
OSHA field staff and consultation personnel should be aware of the potential for NRL allergy in workers exposed to NRL products.
Please distribute this bulletin to all Area Offices, State Plan States, and Consultation Projects. Copies of this TIB may be used for outreach purposes.
This technical information bulletin (TIB) is not a new standard or regulation. This TIB is advisory in nature and informational in content. The failure to implement a specific recommendation in this TIB is not in itself a violation of the General Duty Clause of the OSH Act. The General Duty Clause [Section (5)(a)(l)] requires each employer to furnish to each employee employment and a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his employees.
*The Directorate of Technical Support issues technical information bulletins (TIBs) to provide OSHA field staff with information regarding safety and health issues. TIBs are initiated based on information provided by the field staff, scientific investigations, technical publications, and concerns expressed by safety and health professionals, employers, and the public. This information has been compiled based on a thorough evaluation of available facts, and in accordance with appropriated parties.
**The American Academy of Allergy, Asthma, and Immunology and American College of Allergy, Asthma, and Immunology issued a joint statement July 21, 1997 which advises that latex glove purchase and use should consist of only low-allergen, powder-free latex gloves. The National Institute for Occupational Safety and Health (NIOSH) also recommends that if latex gloves are chosen, provide and use reduced protein, powder-free gloves.(18) A 1998 Guideline for infection control in health care personnel, consisting of consensus recommendations of the Hospital Infection Control Practices Advisory Committee (HICPAC) to the CDC, included several recommendations regarding latex hypersensitivity, but did not include advice about use of powder-free gloves throughout an institution and made no recommendation for institution-wide substitution of non-latex products in health care facilities to prevent sensitization to latex (Am J Infection Control 1998;26:339).Latex References