As is well known, NRL has been used as a material for the production of gloves for almost a century. Throughout the 1990s there were increasing concerns about transmittable diseases, particularly HIV infection and hepatitis, which resulted in a dramatic increase in the use of NRL gloves. Escalating glove use in the 1990s was associated with the rise in reports of allergic reactions to NRL gloves among healthcare workers [1,6,7,8,9,10]. The increased demand for gloves led to an upsurge in glove production, especially in Malaysia. Between 1987 and 1989 the Malaysian Rubber Development Board received over 400 applications to form glove companies where previously only 25 existed . Early on in the history of NRL allergy, some authors [12,13] suggested that the increased production in response to the sudden upsurge for latex gloves often led to inadequate leaching to reduce protein levels.
The healthcare community requires medical gloves, both for examination and surgery, in order to provide a barrier that prevents transmission of micro-organisms to and from patients . Many factors are involved in the choice of materials for the production of medical gloves, which relate to both the protective effect as well as ease and comfort of use [14,15]. For a large number of healthcare practitioners, NRL continues to be the glove material of choice [15,16].
The negative aspect of NRL glove use, linked to the allergy problems, has gained substantial media coverage, in addition to the publication of a significant number of scientific papers. In reaction to the media and scientific coverage, and to rising compensation claims, many hospitals around the world have implemented new latex allergy and glove policies, resulting in the substitution of NRL gloves with synthetic gloves in certain areas, on specific patients or by sensitized staff. More recently, a number of high profile hospitals, exemplified by Johns Hopkins Hospital in Baltimore, Md., USA, and the Cleveland Clinic’s network of nine hospitals in Cleveland, Ohio, USA, have gone ‘latex free’ . As a result, a small but increasing number of medical practitioners only have access to gloves made from synthetic materials. Such policies require full consideration of all of the factors involved, including also glove functionality as well as costs incurred, both directly and indirectly on the environment.
Following recognition of the problem of NRL sensitivity in the late 1980s and early 1990s, many changes were made in the production processes for NRL gloves and in the implementation of latex-sensitivity protocols in hospitals. In recent years, these changes have resulted in a significant reduction in the prevalence rates of allergic reactions to NRL. Experience from the Mayo Clinic, Rochester, Minn., USA  and Finland  showed that the change by an institute or hospital district specifically to low-allergen gloves or to gloves with undetectable allergen contents, led to a decrease in the incidence of new cases of occupational allergy. In Germany, Allmers et al.  showed that a combination of educating physicians and administrators, together with regulations requiring that healthcare facilities only purchase low-protein, powder-free NRL gloves, can even lead to prevention of sensitization.
This review compares the key properties of gloves made of NRL and synthetic source materials and examines glove barrier and functional characteristics, recent changes in glove technology, developments in NRL allergen measurement methodology as well as priority given by clinicians and other health care workers. The Anglophone literature limited largely to the period from 1990 to 2010 was surveyed for original research reports and review articles addressing also specifically the evidence for the consequent reductions in risk of allergic reactions and changes in the epidemiology of NRL allergies.
Glove Source Materials
Many plants produce liquid latex, but the natural material, NRL, used in rubber manufacture is almost exclusively obtained from the Hevea brasiliensis tree. It contains the rubber polymer, cis-poly-isoprene, as well as varying amounts of a large number of different proteins [20,21,22]. Various chemicals, such as accelerators, activators, anti-oxidants and vulcanizing agents, are used in the manufacture of medical gloves [; for review, see ] but a large proportion of these chemicals are then leached out in the further stages of production, through processes such as ‘wet-gel leaching’. These leaching processes also remove the majority of the water-soluble proteins found in NRL .
A study in the USA in 2004 performed post-usage examination and testing of surgeons’ gloves after routine surgical procedures. The results revealed higher after-use defects for non-latex compared with latex disposable gloves . Compared with NRL gloves, the odds ratio for defects was 1.39 (95% confidence interval 1.12–1.73) for neoprene and 1.90 (95% confidence interval 1.15–3.13) for nitrile gloves. In addition, the surgeons reported significantly greater satisfaction with regard to factors such as quality, safety and durability for latex compared with latex examination gloves. These results should probably be treated with caution because the surgeons had never used non-latex gloves before for routine surgery (acknowledged by the authors as a possible bias) and only 215 nitrile gloves were used compared to 2,647 latex and 3,624 neoprene gloves. In addition, the main difference in the study was in visible leaks, with no significant difference in water leaks, which may be explained by the low tear propagation strength of nitrile/neoprene. Similar differences between neoprene and NRL have been demonstrated in another study  where it was noted that punctures in neoprene gloves were detected more readily by surgeons than punctures in NRL gloves.