Food Protection Trends - August 2008 - 576

TABLE 5. Comparison of properties of latex, vinyl and nitril gloves (119) Tensile Tear strength 30 MPa 27 MPa 11 MPa Elasticity strength 22.0 N/mm 3.9 N/mm 4.2 N/mm Softnessb Biodegradabilityc Barriera Latex Nitril Vinyl a b c < 5% < 5% 50% 800% 650% 400% 1.4 6.4 3.0 92% 6% 8% expressed in % gloves that show leakage after intensive use Modulus M300 expressed in MPa (lower numbers denote softer material) expressed in loss of weight after 12 months user’s behavior. Furthermore, it is simple and very quick compared to normal handwashing with soap and water. The disinfectant under development for this device, known as MD200, is said to contain no alcohol, chlorine or iodine. Therefore, its use should neither cause discomfort nor irritate the skin, and hence should invite more frequent disinfecting. Although it is the health sector that is the main target group for the product, the AHS offers huge possibilities for the food sector as well. In fact, the disinfection devices can be placed in any area where bacteria are transferred by human handling, such as in the workplace, airports, bars and restaurants. Make glove, not war Protecting hands with gloves. Gloves provide a physical barrier between hands and contaminated surfaces, resulting in the protection of food against contamination by microbial pathogens via food operators. However, the available literature is complicated regarding the efficacy of gloves in preventing food contamination. Most available data originate from the medical sector, and transposing the conclusions to the food industry is not straightforward, for the following reasons. First, gloves used by medical staff are usually of better quality than the gloves used in the food industry. Second, experiments that examine the contribution of gloves to the reduction of the risk of contamination usually focus only on the analysis of glove leakage and do not accurately mimic the reality of food processing. Therefore, the available experimental data should be critically analyzed (84). Experiments that examine the transfer of microorganisms from contaminated hands to food demonstrate that wearing gloves reduces the translocation of microorganisms significantly. In the retail sector, gloves are especially useful to prevent the transfer of fecal pathogens from fingertips to food when the hands have not been properly washed. However, this reduction is not absolute (84). Several studies show that bacteria are able to pass through the physical barrier of gloves (24). It was demonstrated, for instance, that wearing gloves cannot prevent the transfer of bacteria from contaminated meat to hands but only reduces it by 2 log units, compared to the transfer without the use of gloves. Even the frequent change of gloves (e.g., every hour) could not prevent food contamination (34, 35). Contact time plays an important role in the transfer of microorganisms. Several publications show that the risk of transferring microorganisms through the glove barrier increases with contact time. (84). Even during very short contact periods (5 s) the migration of microorganisms through the gloves was reported (92). The number of microorganisms transferred from contaminated food to hands is comparable to the number of microorganisms present after handwashing with soap (19). In contrast to bacteria, viruses do not cross the glove barrier very easily. Hence, wearing gloves gives better protection against contamination by viruses, when gloves are used properly (10, 21). However, protection against viruses is not absolute, as the transfer of bacteriophages, Hepatitis B, and Herpes Simplex virus across the glove barrier has been reported (51, 52, 74, 101). Choice of gloves. Gloves made of natural rubber (latex) are commonly used because of this material superior properties compared with synthetic alternatives such as nitril and vinyl (Table 5). Latex gloves have considerably better strength, elasticity and comfort. Vinyl gloves are characterized by a lower efficacy of the physical barrier, and in addition, more frequent leakage is observed (50); when used intensively, vinyl gloves show approximately 13 times more leakage than latex gloves (119). Nitril gloves provide a physical barrier that is comparable to that of latex gloves, but they tend to break more easily than latex gloves. Despite the fact that nitril gloves are superior in several ways to vinyl gloves, the latter are more frequently used, mainly because of their lower cost than nitril gloves (22, 99, 119). Some authors have investigated the use of two pairs of gloves, which it was assumed would provide an enhanced physical barrier. Indeed, this has been confirmed in the case of vinyl gloves as the use of two pairs reduced the risk of leakage by one-third, but with latex or nitril gloves, the use of two pairs does not have the same enhanced effect. On the other hand, double-layered gloves of any kind will provide better protection (119). Gloves with microspheres that release chlorine dioxide, activated by light or moisture, are a recent development in glove technology (5). When chlorine dioxide is dissolved in water, it has antibacterial activity. Such gloves are not harmful to hands and are not uncomfortable. Although some authors are not convinced of their efficacy (75), it is clear that such glove technology shows huge 576 FOOD PROTECTION TRENDS | AUGUST 2008

Food Protection Trends - August 2008

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