The most important reason why a healthcare personnel wears a pair of gloves is to prevent transmission of microorganisms to and from the patient. With the onset of HIV and the fear among healthcare providers about cross contamination (patient to healthcare provider), the use of gloves, particularly Natural Rubber (NR) latex gloves, has proliferated. The lives of a great many doctors and nurses have been saved because of this.

However, in recent years, the major preoccupation of the western mass media covering glove usage has been on the negative aspects of NR latex gloves. They have been maliciously portrayed as causing more harm than good to users. There is hardly any discernible coverage of the immense benefits of these gloves. The heap of articles written in journals, magazines and the Internet center almost entirely on the latex allergy problem and the risks associated with it. It is therefore the object of this paper to give a balanced view of the allergy problem and the good characteristics of latex gloves.

As the allergy issue has been comprehensively reviewed by others¹, it is sufficient to highlight here, in a nutshell, an unbiased analysis of the allergy risks arising from the use of gloves.

It is true that certain NR latex proteins can cause Type I hypersensitivity to some sensitized individuals. But, is the problem so prevalent as claimed? The prevalence figure of NR latex allergy among healthcare workers in U.S.A is often quoted to be around 16-17%². This implies that 1.25 million healthcare workers are already sensitized. Even more alarming is one figure quoted in the Internet that 8% of the 268 million current population or 21.4 million Americans are already affected and at risk daily.

It is rather ironical to compare these figures with those reported for the Malaysian high- risk groups³. In Malaysia where latex is being sloshed around daily for decades in plantations and latex product factories, it is really mystical that hardly anyone suffers from latex protein allergy.

The above discrepancy notwithstanding, it is a fact that virtually all experts writing in peer-reviewed journals or testifying under oath generally agree that the exact prevalence of NR latex allergy is simply unknown^2,4. At doubt also is the validity of the techniques used to study prevalence. Serological tests that are often used for such studies in U.S.A. have been shown to be unreliable as an indicator of latex allergy⁵.

There is a growing threat in the West, particularly U.S.A., to ban powdered latex medical gloves from the healthcare setting. This is based on the claims that corn-starch powder can cause adhesion formation, allergy and infection. Recently, three States in America namely Oregon, New York and Minnesota, have begun enacting the powder-free bills. This may be considered to be a case of over-reaction. In fact, if there is a need to ban anything that can cause health-related problems such as sensitization, top in this list should include a variety of useful drugs that save lives like penicillin and aspirin; common fruits⁴ such as avocado, banana and chestnut that give us vitamin C. On the same basis, there may be a need to cut down plants that flower and give pollens that cause hay fever so as to eliminate the allergy problem.

It is only a speculative theory that sensitization can be effected through breathing aerosolized cornstarch. In fact, it is impossible to state retrospectively when an individual became sensitized and what caused the sensitization². Environmental factors, fruits, bee stings and others can bring about this adverse immunological response.

Indisputably, it may be necessary for some of the sensitized individuals, particularly the highly sensitized ones, to avoid latex. But, for normal, healthy individuals, NR latex glove remains the glove of choice. The most important task ahead is to prevent further sensitization of glove users. Although the threshold for sensitization remains unknown, the RRIM has published data⁶ to show that if extractable protein (EP) contents were kept below 100 m g/g of glove (by RRIM-Lowry), almost 100% of latex hypersensitive patients showed no allergic response on skin prick testing. If EP contents were kept below 400 m g/g, the negative allergic response figure was at 60%. Evidently, these results have given users an indication of the level of EP in gloves that they should aim at, not only to prevent an allergic reaction from happening among sensitized users, but also prevent sensitization among non-allergic individuals.

To contain the allergy problem, the key is to keep the EP/allergen level as low as reasonably achievable. Reputable hospitals in Finland and U.S.A have proven that with proper screening and selection of gloves, the risk of latex allergy can be kept to a minimum⁷. The type and use of powder may become irrelevant if the allergen content of the gloves is low enough so that the powder does not bind and carry latex proteins.

There is no gainsaying the fact that a NR latex glove is the barrier material of choice for all healthcare workers. This is not due to its superior barrier properties alone, but also a host of other factors that include its green characteristics and high tensile/tear strength.

Of late, there has been concern among healthcare personnel about the effectiveness of NR latex gloves as a barrier against infectious diseases. A number of articles that carry misleading titles such as "surgical gloves let in viruses", " latex not a barrier", and the likes have appeared. They invariably give readers the wrong impression that these gloves failed because latex films were simply permeable to viruses.

Several years ago, there was also a claim that there were channels in latex films as seen under a scanning electron microscope^8. Although there were counter arguments on the claim, which attributed the channels to artifacts of the microscopy technique⁹, there has not been any direct experimental evidence to refute the existence of channels in latex films. Nonetheless, the implications that there are channels in latex films and hence the films are porous to viruses can be safely discounted. This is based on the findings that latex films which are properly produced are impermeable to viruses and that if laser-drilled or needle punctured holes are artificially introduced, the extent of penetration has been shown to be a function of size and density of the holes as well as size and adsorptivity of the virus on the latex film^10,11.

It is evident, therefore, that latex films leak viruses only when there are holes in them due either to manufacturing defects or the conditions under which they are used/stored. Several other workers have also shown that properly manufactured gloves are effective barriers against HIV, HSV and Echo 9 viruses and that latex is preferred to vinyl for more effective and durable barrrier qualities^12,13,14,15.

Although there is no data to compare NR latex gloves with the newer products that have been approved by the US Food and Drug Administration (FDA) for medical use, namely Tactylon, Elastryn, Dermaprene and Neoprene, these gloves have not withstood the test of time and the volume of usage as NR latex gloves do.

In assessing claims of glove failure, therefore, it is important that factors such as glove specifications, storage and handling are considered¹⁴.

Specifications – Quality control parameters such as quality level for holes or other glove defects (tears, discoloration, dimension) are important. For effective barrier protection, the gloves should ideally adhere to the specifications of the ASTM or other standards organizations.

It may be worth noting that the risk of exposure to virus-containing fluids through the small pin-holes (< 20 m m in diameter in the palm and < 40 m m in the fingers) that are not detected by the water test has been shown to be insignificant as compared to the risk of exposure to the larger holes. Although the figures of acceptable quality level (AQL) of medical gloves may be subjected to revision from time to time, it is generally accepted that the water test is good enough as a QC/QA measure to keep the risk of transfer of fluid between medical personnel and patient to a minimum¹⁶.

Gloves of the right size should also be used as inappropriate fit of the gloves on users’ hands may indirectly cause holes to form when using instruments through clumsy hand movements.

Storage and handling – Proper storage and handling of the gloves, regardless of the material used, is essential to ensure that the barrier properties are not compromised.

It is generally accepted that NR latex gloves offer the best barrier protection against diseases. If they fail, it is likely that the quality of the glove used is suspect, or damages on the gloves have taken place during use.

There is an increasing pressure for consumer goods to be made of green materials. Unlike its synthetic alternatives, NR latex glove is an inherently environmentally-friendly material.

NR itself is a sustainable and renewable resource. The rubber trees annually remove 363 million kg of carbon dioxide from the atmosphere and replace it with life-saving oxygen¹⁷. This helps to combat the greenhouse effect and global warming which are of great concern to world ecologists. Rubber and rubber products can biodegrade^17,18,19,20 by a combination of chemical and biological attack. Actinomycetes such as Nocardia have been widely documented as microorganisms responsible for the degradation of NR products. Other members of the Actinomycetes group such as Streptomycetes are also shown to attack rubber. It has been shown that the thin film from latex gloves would rapidly biodegrade with weight loss of 75% after 2 weeks of exposure to Nocardia.

Among other attributes of NR vis-à-vis synthetics are the amount of energy needed to produce these materials. While it requires only 16 GJ/ton in the case of NR, the energy consumption figures range between 108 and 174 GJ/ton for the synthetics^21.22. Although it may be argued that some extra energy is required to process the latex to gloves, this is insignificant as compared to the total energy inputs required for the synthetics. It is evident that NR is greener in energy terms than the synthetics.

The presence of sulphur in medical gloves may pose a problem for their disposal by incineration. But, this problem is also present for synthetic gloves. Use of radiation or peroxide prevulcanized latex would help to overcome this pollution problem. Research is continuing to overcome whatever limitation NR latex gloves may have in improving further their green image.

From the foregoing discussion, it is evident that the benefits of using NR latex gloves outweigh the risk of latex protein allergy. For the highly sensitized individuals, latex avoidance may become unavoidable. But, these individuals must be made aware of the barrier-integrity limitations of some of the synthetic gloves used. Until better alternatives are found, NR latex glove is still the glove of choice as it offers the best barrier protection to healthcare personnel. To minimize risks of sensitization, low protein/allergen gloves are recommended.

The author wishes to thank Dr. E.L. Ong and officers of the Latex Technology Division of the RRIM, particularly Dr. Che Hasma and Mr. K.P. Ng for their useful comments.

1. Jordan N. Fink (1995) Latex Allergy: Immunology and Allergy Clinics of North America. Vol. 15(1). Pub. by WB Saunders Co., Philadelphia.
2. Allegiance Healthcare Corp. (1997) Natural Rubber Latex Allergy Update. 
3. Nasaruddin B.A. et.al. (1994) Prevalence Study on Type I Latex Hypersensitivity among High Risk Groups in Malaysian Population. RRIM Workshop on Latex Protein Allergy, Kuala Lumpur.  
4. Turjanmaa, K. et.al. (1995) Natural Rubber Latex Allergy - The European Experience. p. 81 in Reference 1 above. 
5. Hasma Hashim et.al . (1997) Binding Pattern of Fresh Latex Serum Proteins in the IgE Antibodies of Rubber Tappers (in press). 
6. E. Yip et.al. (1994) Allergic Response and Levels of Extractable Proteins in NR Latex Gloves and Dry Rubber Products. J. nat. Rubb. Res., 9(2), 79–86. 
7. K.J. Kelly (1995) Management of the Latex Allergic Patient. p. 148 in Ref. 1 above. 
8. C.M. Roland (1993) The Barrier Performance of Latex Rubber. Rubber World. 
9. M.D. Morris and T.D. Pendle (1993) Latex Films are Barriers to Viruses. Rubber World. 
10. C.D. Lytle (1991) Important Factors for Testing Barrier Materials with Surrogate Viruses. Appl. & Environ. Microbiology, p.2549-2554. 
11. H.R. Kotilainen et.al. (1992) Ability of 1000 ml Water Leak Test for Medical Gloves to Detect Gloves with Potential for Virus Penetration. Performance of Protective Clothing: Fourth volume, ASTM STP 1133 by James P. McBriarty Eds. ASTM, Philadelphia. 
12. Dalgleish A.G., Malkovsky M. (1988) Surgical Gloves as a Mechanical Barrier Against HIV. Br. J. Surg. 75: 171-72. 
13. A. Zbitnew et. al. (1989) Vinyl Versus Latex Gloves as Barriers to Transmission of Viruses in the Healthcare Setting. J. Acquired Immune Deficiency Syndromes, 2, 201-204. 
14. D.M. Korniewicz (1995) Barrier Protection of Latex , 123-137 in Reference 1 above. 
15. D.M. Korniewicz et.al. (1990) Leakage of Virus through Used Vinyl and Latex Examination Gloves. J. Clin. Microbiol., 787-788. 
16. Ron Carey & Dave Lytle (1997). FDA Scientists Study Quality Assurance Tests or Latex Gloves – User Facility Reporting Bulletin, p.5, Spring 1997. 
17. D.K. Burchette (1989) A study of the effect of Balloon Releases on the Environment NABA. 
18. F.C. Low et.al. (1992) Microbial Degradation of Natural Rubber J.nat.Rubb. Res., 7(3), 195-205. 
19. A. Tsuchii & K. Takeda (1990) Rubber-degrading Enzyme from a Bacteria Culture Appl. Environ. Microbiol. 56(1), 269-274. 
20. A. Tsuchii et.al. (1985) Microbiological Deterioration of Natural Rubber Vulcanizates Appl. Environ. Microbiol., 50(4), 965-970. 
21. Wan Abd. Rahaman (1994) Natural Rubber as A Green Commodity. Rubb. Dev., 47(1/2), 13-16. 
22. K.P. Jones (1994) Natural Rubber As A Green Commodity – Part II. Rubb.Dev., 47(3/4), 37-41.

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