GUIDELINES FOR LATEX GLOVE USERS CONTENTS Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . page 1 Natural Rubber Latex . . . . . . . . . . . . . . . . . . . . . . page 1 Reactions Associated with the Use of Natural Latex Gloves . . . page 2 A) Irritant Contact Dermatitis B) Allergic Contact Dermatitis C) Immediate Reactions i) Contact Urticaria/Systemic Reactions ii) Anaphylactic Reactions Prevalence of Occupational Latex Allergy and WCB Experience . . page 4 Medical Assessment of the Affected Worker . . . . . . . . . . . page 4 1) Allergic Contact Dermatitis (Rubber Allergy) 2) Immediate Reactions (Latex Allergy) Workers at Risk of Developing Latex Allergy . . . . . . . . . . page 5 Control of Exposure . . . . . . . . . . . . . . . . . . . . . . page 6 Selection and Care of Gloves . . . . . . . . . . . . . . . . . . page 7 A) Barrier Quality B) Allergenicity C) Cost D) Care of the Gloves Management of the Sensitized Worker . . . . . . . . . . . . . . page 8 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . page 8 GUIDELINES FOR LATEX GLOVE USERS INTRODUCTION The use of rubber gloves has prevented many infectious diseases over the years, and with the implementation of universal precautions glove usage has been increasing steadily. However, the use of rubber gloves has been recognized as a cause of irritant and delayed allergic skin reactions. In the past ten years, there have been increasing numbers of reports of more severe health effects associated with use of latex rubber products, ranging from urticaria (hives), rhinitis (runny nose) and conjunctivitis (red, irritated eyes) to life-threatening anaphylatic reaction. These immediate allergic reactions are thought to be due to a special (Ige) mediated immune response to naturally occurring latex proteins. This document provides a description of the various types of reactions to latex, guidelines on the selection of gloves, and advice on the assessment and accommodation of the affected worker. NATURAL RUBBER LATEX Natural latex is the milky sap collected from the rubber tree, Hevea braziliensis, in much the same way as maple syrup is collected. Ammonia, sulfites, and other chemicals are added at the collection sites to prevent autocoagulation. Natural latex contains carbohydrates, lipids, phospholipids, proteins and rubber polymers (cis-1, 4 polyisoprene). The total amount of protein is about 1.7%. Centrifugation concentrates the natural latex to 60% solid phase, and removes a large percentage of water soluble impurities (including protein) in the liquid phase. "Natural rubber latex" refers to the concentrated liquid natural latex which is used to make products such as gloves, condoms, and balloons. Gloves are made by dipping a glove-shaped mold into the natural latex emulsion, to which various chemicals are added to suit the process and/or to ensure desired physical and chemical properties of the finished product. These rubber additives include accelerators, preservatives, antioxidants, antiozonants and plasticizers. REACTIONS ASSOCIATED WITH THE USE OF NATURAL LATEX GLOVES The reactions related to latex glove use can be divided into the following categories: A) Irritant Contact Dermatitis B) Allergic Contact Dermatitis (Delayed Type Hypersensitivity) C) Immediate Reactions (Immediate Type IgE Mediated Hypersensitivity) i) Contact Urticaria/Systemic Reactions ii) Anaphylactic Reactions A) Irritant Contact Dermatitis This is a non-allergic skin rash characterized by dry, flaky skin with papules, cracks or sores. Often the cause may be repeated or prolonged irritation from sweating under the gloves or from gloves rubbing against the hands. The frequent use of gloves may also aggravate pre-existing atopic hand dermatitis. Residual soaps, cleaning agents or disinfectants may irritate the skin. Other chemicals may contaminate the glove through pinhole leaks or, in the case of glutaraldehyde, directly penetrate latex gloves. Manufacturing variations may result in excess additives such as accelerators, preservatives, or vulcanizing agents. These additives may cause irritation but are more commonly know to cause contact allergic dermatitis. Most workers with irritant dermatitis find relief using a cotton or a non-latex liner before donning the latex glove. B) Allergic Contact Dermatitis This is a skin condition caused by cellular immune response in the body activated by repeated contact with the allergen. During the acute phase, the rash appears within 48 to 96 hours after exposure, usually from the tips of the fingers to where the glove ends at the wrist. This reaction is known as delayed hypersensitivity. With time, the skin may become dry, red, crusted and thickened with hard bumps, sores and sometimes blisters. Once an individual is sensitized to a specific allergen, contact with even small amounts of the allergen may result in recurrence or worsening of the rash. The rubber polymer (cis-1, 4 polyisoprene) is not known to cause allergic contact dermatitis. Rubber chemicals added in the manufacturing process are among the most frequent causes of both work- related and non-work-related allergic contact dermatitis. Use of rubber gloves appears to be the main cause of work-related allergic dermatitis of the hands. The term "rubber allergy" will be used in this guidance note to refer to sensitization to rubber chemicals. The rubber chemicals implicated in allergic contact dermatitis include accelerators, anti-oxidants, anti-microbials, emulsifiers and dispersing agents, colorants, and stiffeners, which may be added during the manufacturing process. The more common sensitizers/allergens are thiurams and carbamates. Both are accelerators, which speed up the vulcanization or curing process to cross-link the rubber polymer to produce an elastic product. Sensitization occurs more easily through already damaged skin. Thus a pre-existing irritant dermatitis (skin rash) may predispose to the development of allergic contact dermatitis. It is prudent for individuals with hand dermatitis not to have direct skin contact with latex and to wear vinyl or other non-latex gloves to prevent the development of rubber allergic contact dermatitis. Individuals sensitized to rubber chemicals should be aware that many of these chemicals may also be present in non-rubber products, such as plastics, pesticides, oils and organic dyes. Contact dermatitis has occurred from some of these sources. Ingestion of the allergen causing the contact dermatitis may also be associated with a flare-up of the skin eruption. C) Immediate Allergic Reactions Immediate allergic or hypersensitivity reactions are mediated by a class of antibodies known as IgE, which quickly recognize the specific allergen from a previous exposure. The allergen in latex products is thought to be a protein component which is leachable from natural latex. Because of variability of sources and techniques, several latex protein allergens have been isolated and purified, with molecular weights most frequently found at 14.5 kd and 30 kd. The protein allergens have been found in water-soluble extracts from latex rubber film. They may also be adsorbed to glove powder, which may then become airborne. Exposure to such airborne latex protein can explain the eye, nose and respiratory symptoms of latex allergy. Depending on the route of exposure, the amount of latex allergen, and the degree of individual sensitivity, the following immediate reactions can occur: i) Contact Urticaria/Systemic Reactions Sensitized individuals may develop localized itching or discomfort followed by hives within 5 to 60 minutes after donning latex gloves. Exposure to airborne latex allergen (commonly adsorbed on the glove powder) may cause itchiness of the eyes, conjunctivitis (inflammation of eyes), eyelid swelling, rhinitis (runny nose), shortness of breath or asthma, dizziness, and tachycardia (rapid heart beat). Upon removal from exposure, symptoms usually disappear without treatment within a period of 30 minutes to 2 hours. ii) Anaphylactic Reactions This includes the above symptoms with the addition of hypotension (low blood pressure). Anaphylactic reactions are life-threatening. More than fourteen deaths attributed to latex anaphylaxis have been reported, all due to the latex cuff used during barium enemas. No death was reported from occupational exposure. PREVALENCE OF OCCUPATIONAL LATEX ALLERGY AND WCB EXPERIENCE In the past ten years, there have been increasing numbers of reports of immediate latex allergic reactions, including anaphylaxis, in individuals exposed to latex. The prevalence of latex allergy is unknown. Turijammaa in one study shows that approximately 2.8% of non-health care workers have positive scratch chamber tests, while 4.5% of hospital employees, 5.6% of O.R. nurses and 7.4% of O.R. doctors show positive results. Sussman's study shows similar results; 10% of the 101 physicians, radiologists and anesthesiologists have positive skin tests. A survey of the U.S. Army Dental Corps shows that the prevalence ranged between 8.8% to 13.7%. The Ontario Workers' Compensation Board (WCB) claims up to 1992 were reviewed and sixty cases were allowed. Eleven claims were excluded because of misclassification. The first claim was reported in 1986 by Tarlo and Wong. Twenty-five of the forty-nine allowed cases were from health care facilities. Six cases of reactivity airway claims were allowed. Two were from a glove manufacturer and four were from health care facilities. Two cases of adverse reactions were from hospitals. The above data also shows that there is an increasing number of claims from health care workers for latex sensitivity. Latex dermatitis and sensitizers are generally under-reported and there is a lead time between the time a claim is filed and the time it is allowed. Therefore, the actual prevalence of latex allergy was suspected to be much higher than what has been reported. MEDICAL ASSESSMENT OF THE AFFECTED WORKER A history of exposure covering the use of chemical and physical agents, including the use of gloves should be taken. The medical history should include inquiries into previous skin and other allergic reactions, especially from direct or indirect contact with rubber materials both at home and at work. A physical examination of the skin and other involved systems should be carried out. Clinical testing may be required to make a definite diagnosis. Depending on whether latex allergy is present from the history, various tests should be carried out. The following is a list of the clinical tests that should be considered for rubber and latex allergy: 1) Allergic Contact Dermatitis (Rubber Allergy) Patch testing with the rubber chemical is required to make a definitive diagnosis. Patch testing also provides guidance in avoiding the specific allergen by selecting gloves without the offending ingredient. Carbamate mix and thiuram are two of the allergens used in the standard patch testing. Some dermatologists also have a specialized "rubber tray" in which the individual chemical, e.g. thiuram or carbamate, is used. 2) Immediate Reactions (Latex Allergy) Latex extracts have been used to demonstrate immediate sensitivity by skin prick testing (SPT). Skin tests have the advantage of being sensitive and rapid but severe allergic reactions have occurred. Therefore, a skin test should be done with the appropriate agent(s) and technique, and in a controlled environment. Specific latex allergen(s) have not been isolated and purified to provide standardized allergens for testing. The predictive value of a positive skin test in asymptomatic individuals is not known. Skin testing can only confirm the diagnosis of latex allergy and has no value in the prediction of the likelihood of an anaphylactic reaction. The known risk factors for anaphylactic reaction are the total serum IgE level, the presence of food allergy and the prior history of greater than nine surgical procedures. In vitro testing such as the latex radio-allergosorbent test (RAST) is safe but lacks sensitivity and specificity. Further studies are required before offering routine screening. WORKERS AT RISK OF DEVELOPING LATEX ALLERGY 1. Individuals with a personal history of atopy--e.g., hay fever, asthma, or food allergy with positive skin tests--appear to be at increased risk for developing clinical latex allergy. 2. Individuals who use or manufacture latex products (e.g. gloves) or who are exposed to latex products on a regular or frequent basis (e.g. from repeated surgery) appear to be at increased risk. 3. There appears to be a cross reactivity between latex protein, bananas, avocados, and chestnuts: i.e., individuals allergic to these foods may also be allergic to latex. Papaya and other tropical fruits may also give a cross reaction. It is unclear whether these individuals are at a higher risk. CONTROL EXPOSURE Attempts should be made to reduce or control latex exposure to avoid sensitization of workers. 1. Staff required to wear latex gloves should receive training about the potential health effects and risk of sensitization related to latex. Staff working in high risk areas (i.e., operating rooms and emergency rooms) should be targeted first. 2. The use of latex gloves for various tasks should be reviewed to determine if it is appropriate for the level of protection and degree of risk, to comply with universal precautions. 3. Where possible, hypo-allergenic non-powdered gloves should be used to reduce skin exposure and exposure to airborne latex proteins adsorbed onto the powder. 4. Latex producers and rubber goods manufacturers are looking at methods to reduce latex protein content levels during production. Leaching, centrifugation, chlorination and use of enzymes have been shown to lower the levels of water-extractable protein. Research has demonstrated variable latex antigenicity between brands and between lots of gloves. Sensitization may be related to a high protein level in the latex products and manufacturing processes may never lower the protein allergen to levels that are safe for sensitized individuals. However, improved processing may reduce the protein levels enough to reduce the sensitization of susceptible workers. Before ordering a specific model of glove, the employer should check with suppliers to ensure that the glove to be purchased has low extractable protein levels and low levels of known rubber sensitizers. 5. Workers at increased risk of developing latex sensitivity--i.e., those who are atopic with food allergies or irritant dermatitis--should be encouraged to wear glove liners under latex globes, and, where practicable and appropriate, to wear non-latex gloves. When liners are used, they should be the impervious type, e.g. polyethylene liners or PVC liners. Cotton liners should not be used because of the possibility of latex particles migrating through the liners. In addition, no lotion or barrier cream should be used under the gloves. The ingredients in the lotion (both petroleum-based and aqueous-based) may react with the latex and this may compromise the integrity of the gloves. SELECTION AND CARE OF GLOVES When selecting a specific glove for the job, one should consider the following three factors: barrier quality, allergenicity, and cost. A) Barrier Quality When new surgical and examination gloves are being purchased, gloves approved by the Canadian General Standards Board or equivalent gloves should be considered, to ensure the product chosen meets recognized standards of quality and performance. (The CGSB's telephone number is (613) 941-8709.) Since this is a voluntary program, glove manufacturers who do not apply for certification may have gloves of equivalent quality. Information should be obtained from the supplier regarding standards of manufacturing. One should always keep in mind that even with CGSB-approved gloves the manufacturers are still allowed to have 1.5% of the surgical gloves and 4% of the examination gloves with leakage or holes. A good manufacturer should be able to provide the Acceptable Quality Level (AQL) for its product and should also be able to provide the percentage of manufacturing defects for each lot of gloves. The above information also stresses that hand washing is an essential part of universal precautions. Also, the CGSB program deals only with the manufacturing and processing of the gloves and the testing of their physical properties. CGSB approval does not address the allergenicity of gloves. B) Allergenicity Glove suppliers may use the term "hypo-allergenic" to indicate one or more of several different properties. Gloves described as "hypo- allergenic" may be: latex gloves with only some of the usual sensitizing additives; low protein latex gloves; powderless latex gloves; latex gloves with a non-latex inner lining; or non-latex gloves. Details should be obtained from the manufacturer or supplier. C) Cost Cost is an important factor to consider in the selecting of gloves. However, one should not sacrifice barrier quality or hypo-allergenicity for economic reasons. D) Care of the Gloves One also has to bear in mind that even with all the additives, latex gloves are subject to deterioration from both chemical and physical agents during shipment and storage. In general, latex gloves should not be stored in extreme temperatures or near ionizing radiation or other chemicals. Good manufacturers will provide an expiry date on the individual package of surgical gloves. Expired gloves should not be used. MANAGEMENT OF THE SENSITIZED WORKER 1. Workers with symptoms suggestive of latex allergy should be encouraged to report to the Employees' Health Service for assessment. Under- reporting of glove dermatitis is common in health care settings. This leads to delayed diagnosis and may cause avoidable life-threatening reactions in workers. A written accommodation policy is recommended to alleviate sensitized workers' concerns about continuing work. 2. It is essential that the employer develop a policy and protocol to assess and accommodate individuals who develop rubber or latex sensitivity. Once a suspected case is reported, a prompt referral to a specialist, i.e., an allergist/dermatologist, is essential. In the interim, non-latex gloves or non-latex glove liners should be provided by the employer and used by the worker. 3. When a diagnosis of latex contact allergy is confirmed, the employer should accommodate the affected worker. Alternative gloves or non- latex gloves should be provided to individuals. Powderless gloves or hypo-allergenic gloves may also be used by the co-workers. Extremely sensitive individuals may have to be re-assigned to areas where no latex gloves are used, because of sensitivity to airborne latex protein. 4. Avoidance of latex is a formidable task since many medical devices contain components made of natural rubber latex and so do many consumer products. Individuals with anaphylactic reactions should be advised to wear proper identification which warns of the serious nature of their latex allergy. Such individuals should carry their own epinephrine auto-injector and stock up with several pairs of non-latex gloves in their cars. Necessary precautions must be taken during medical and surgical procedures to avoid contact by these individuals with latex gloves or devices containing latex to prevent anaphylaxis. Many researchers, manufacturers and health care facilities have established lists of both health care products and household products that may contain latex and the possible alternatives for them. A current list should be obtained. 5. A latex-free emergency department, pharmacy and surgical protocol should be available in a hospital for all individuals with latex sensitivity (both workers and patients). SUMMARY The use of latex gloves has prevented far more illnesses than it has caused. One should consider the barrier quality, allergenicity and cost when selecting a glove. Appropriate training should be provided to the workers on the selection, protective effectiveness, limitation and potential health effects of the gloves. Should a worker develop symptoms related to the use of gloves, he or she should be properly assessed in a timely manner. The employer should attempt to accommodate an affected worker. --------------------------------------------------------------------------- Professional and Specialized Services September 21, 1994 Occupational Health and Safety Branch ISBN 0-7778-3274-7 Ministry of Labour 400 University Avenue, 8th Floor Toronto ON M7A 1T7 Cette publication est �galement disponible en fran�ais sous le tire <> (ISBN 0-7778-3275-5).