Universal Design to Limit Food Cross-Contamination: Incased Set of Kitchen Utensils with Five Color-Coded Food Chopping Boards and Knifes

This-study is focused on a-conceptual-design of a-kitchen-appliances/utensils-set, comprising of five-color-coded food-chopping-boards and five-matching-color-coded-knifes, to-reduce cross-contamination at private-homes, aswell-as at food-establishments. Selected-relevant-Patents, as-well-as products, available locally and internationally, were analyzed. The-Joseph-Joseph IndexTM Color-Coded Chopping-Boards set (of four), was chosen as a-point of reference for the-current-design; its-seven-identified-limitations have-directed the-scope of the-current-design. Target-specifications/objectives, of the-set, were formulated from the-document-analysis, while Pair-wiseComparison-Charts were-used, to-rank the-importance of the-objectives, in the-different-levels. The-best-rankeddesign (out of the-four-alternatives made) was chosen, via standard Engineering-Design Weighted-DecisionMatrix (EDWDM) and ‘Drop and Re-vote’ (D&R) method. 2D-drawings, of the-best-design-alternative, were created via computer-aided-design (CAD) AutoCAD-software 2018, while 3D-modeling, of the-set and all-itscomponents, was produced by Autodesk-Inventor-Version: 2016 (Build 200138000, 138). Designed-labels (positioned on each-board and each-knife, as-well-as on the-set itself, as an-inclined-panel) were introduced, tocater for the-people with color-blindness (according to-the-fundamental-principles of the-Universal-design), and also to-avoid-confusion (as a-reminder which board is which) for all-users. The-study adopted ‘analysis’ method of materials-selection. The-main objectives, of the-intended-set, was used as a-guide, in-preliminary-materialsselection. This-concise-study has focused on conceptual-design only; and, hence, it-is further-recommends to: (i) carry-out a-detailed-design; (ii) select a-specific-material (out of the-group, identified by this-study); (iii) choose a-mode of fabrication of the-set; (iv) examine the-possibility of incorporating of anti-microbial-agent(s) and/or coating(s); (v) fabricate the-prototype(s); (vi) conduct explorative-use-ability-trials; and (vii) analyze themarketing-aspect of the-final-set. This-work is potentially-beneficial-to engineering-product-design students and faculty, as-well-as to-households and food-establishments (subject-to successful-implementation).


Food-borne-diseases and their-impacts.
Food-borne-diseases are regarded-as acute-illnesses, associated-with the-recent-consumption of food, having normally a-short-incubation-period, and symptoms, with gastrointestinal-features, including: vomiting, diarrhea, and abdominal-cramps. In-some-cases, there may be neurological and other-symptoms, connected with thealimentary-tract (WHO, 2008). According to Mukhola (2000), WHO regards illness, due-to contaminated-food, as one of the-most-widespread health-problems, in the-contemporary-world.
Although proper-food-handling, preparation, storage, and feeding-practices may prevent many-food-1.1.5. Survival-rates and multiplication of food-born-pathogens.
On-the-other-hand, food-safety is a-scientific-discipline, describing handling, preparation, and storage of food, in-ways, that prevent food-borne-illness (Abuga et al., 2017). According-to the-discipline, bacteria are themost-common-cause of food-borne-outbreaks, since bacteria are microorganisms with high-reproductive-capacity. According to WHO (2014), bacteria multiply by a-method, called 'binary-fission', where one-bacterium becomes 2, and 2 bacteria become 4, etc. For-example, Vibrio parahemolytica carries-out fission very-quickly, and inconditions, which are good for the-bacteria-growth, it can undergo fission once every-eight-minutes. If eachbacteria splits-in-two, every-eight-minutes, after 3 hours there will be 4,200,000 bacteria and 68,919,470,000 bacteria after 5 hours! From the-above-information, it can be put-forward, that pathogens do not only survive, for a-long-time, on-the-surfaces, but they are also able to-multiply, rapidly; while conducive-environment, such-as temperature, moisture, pH, and oxygen, can speed-up the-growth of the-pathogens.
Surface-cross-contamination (for-example via cutting/chopping boards) is the-6 th most-commoncontributing-factor (out of 32) for food-borne-diseases (CDC, 2013;Gould et al., 2013;. The-next-subsection introduces this-food-contamination-route. Cooking-utensils, including cutting-boards and knifes, washed in-contaminated-water, or food, contaminated, during or after preparation, e.g., moist-foods, contaminated, during or after cooking or preparation, and allowed to-remain, at room-temperature, for several-hours, provide an-excellent-environment for the-growth of pathogens, e.g., Vibrio-cholerae (World-Health-Organization, 2008). It-is well-established that a-highpercentage of food-borne-illness is caused by failure of consumers to-prepare food in a-hygienic-manner. Indeed, a-common-practice in-households, is to-use the-same-kitchen-equipment and surfaces, for both; raw-meat and fresh-produce (Gkana et al., 2016).
Microorganisms, attached-to processing-equipment and surfaces, may escape cleaning and sanitizingprocedures, and proceed to-contaminate processed-product. Pathogens, originating with raw-products can attachto food-preparation-surfaces, which, if not adequately-cleaned, before reuse, can serve to-re-contaminate cookedfoods (Frank, 2001). Figure 2 shows an-example of indirect-cross-contamination, where the-same-board and knife were used for raw-meat and for raw-vegetables (served as salad). Cleaning with cold-water and dish-soap, followed by vigorous-scrubbing and rinsing, practices commonly-followed in-household-kitchens, to-clean cutting-boards, may reduce, but not eliminate the-risk of exposure-to the-pathogens (Soares et al., 2012). Hypochlorite-disinfection, of cutting-board-surfaces, is considered-as the-safest and most-efficient-method (Soares et al., 2012), however many, if not all, households, are basically not aware of the-dangers of inadequate-cleaning and food-cross-contamination. When utensils were not cleaned properly, after they were used, the-transfer-rate was 1.25% from poultry to plastic-board-surface and 45.62% from plastic and knives to lettuce.
From the-common-methods, used in-cleaning of surfaces, at homes, studies have-shown that water and soap, alone, are not enough, to-ensure de-contamination (Barker et al., 2003;Cogan et al., 2002;Scott & Bloomfield, 1990;. To-eliminate the-cross-contamination-route, it-is important to-use separate-surfaces, or to-properly wash the-surfaces, during the-preparation of raw-and cooked-foods, or ready-to-eat-foods (Sampers et al., 2010;Cogan et al., 1999); therefore, in-the-context of this-study, separate chopping-boards, for raw and for cooked-food, are preferable. Poor-hygiene, during preparation and/or consumption of food, in-conjunction-with the-ability of food-bornepathogens to-survive (for a-long-time), and also to-multiply, rapidly, can-lead-to food-cross-contamination. Foodcross-contamination, in-turn, can-lead-to food-born-diseases, resulting in-some-cases, in: (i) severe-sickness, or even death (either immediately, or shortly, after food-consumption), or (ii) in-increased-risk of chronic-diseases (e.g., Guillan-Barre-syndrome, or rheumatoid-arthritis (CAST)).
Food-safety-issues are receiving growing-attention, worldwide, due-to ever-increasing-incidence of food-borne-diseases and their-negative-impacts on the-public-health, economy, and on the-society, at large. Moreover, Luber (2009) points-out that: "There is a focus in many countries to reduce the level of human illness from food-borne pathogens". In-the-same-spirit, this-study is focused on a-conceptual-design of a-kitchenutensils-set of color-coded chopping-boards and knifes, to-reduce food-cross-contamination at private-homes, aswell-as at food-establishments. Universal-design-approach was applied, to-design a-food-chopping-boards-set, with particular-emphasis on the-people with color-blindness-condition; the-next sub-sections provide thebackground-details. A-cutting, or chopping-board, is a-durable flat-board, on which to-place a-product/material, for cutting. Thekitchen-cutting-board is commonly used in-preparing-food, and it-is also-called food-chopping or food-cuttingboard, is an-indispensable kitchen-utensil. Such-boards are often made-of different-materials (see selectedexamples in Figure 3), and come in-various-shapes and sizes.
In-particular: (i) Wood is, somewhat, self-healing; shallow-cuts in-the-wood will close-up, on-their-own. Wood also has natural-anti-septic-properties. On-the-other-hand, wood is intrinsically-porous, which allows food-juices and bacteria, to-penetrate the-body of the-wood; the-moisture is drawn inside, in by-the-capillary-action, until there is no more free-fluid on the-surface, at which-point immigration ceases. Bacteria, in the-wood-pores, are not killed instantly, but neither do they return to the-surface (Cliver, 2006;Abrishami et al., 1994). Hard-woods, with tightlygrained-wood and small-pores, are best for wooden-cutting-boards, which help to-reduce absorption of liquid and dirt, into-the-surface. There are different-types/species of wood, which are used for cutting-boards (Aviat et al., 2016;Xi et al. 2013;Milling et al., 2013), for-example: Acacia cutting-board is often-labeled as the-top-choice for this-kitchen-item; usual-maintenance (oiling), however, is required, to-prevent them from splitting. Acacia is a-highly-sustainable-wood; it has the-appeal of bamboo, but without the-need for international-export.
Walnut cutting-board is the-most-expensive of the-wood-cutting-boards, walnut is a-strong and durablematerial, however it needs maintenance with oil, regularly, otherwise, they can develop very-deep-cracks, making it unhygienic.
Teak cutting-board; Teak, a-tropical-wood, contains tecto-quinones-components of natural-oily-resins, which repel moisture, fungi, warping, rot, and microbes. Teak is also-known for being a-very-durable and waterresistant-form of wood, and for this-reason, it-is a-popular-choice for cutting-boards. Although little-pricy, dueto-its-density, there is minimal-scarring and scratching done, to-it, when used for food-chopping. Besides, teakcutting-board does not require oiling; Teak-wood's tight-grains and natural-coloration make it a-highly-attractive cutting-board-material, both; for aesthetic and durability-purposes. It-is important to-note, however, that there are cutting-boards, made from African-Teak or Rhodesian-Teak, which despite the-name, are not made from thesame-species of wood.
Cherry cutting-board has softer-texture, which, on-one-hand, will be helpful in-protecting knives from damage, but it may also-cause more-damage to the-wood, itself. These-boards should never be submerged inwater, or placed in a-dishwasher, just like the-other-wood-varieties. Another-issue is that the-board should be atleast 2 inches, in-thickness, as it can crack easily; regular oiling, proper-washing, and disinfection are needed.
(ii) Bamboo, although commonly-listed under 'wood', strictly-speaking is not a-wood; thedistinguishing-features is that bamboo grows very-fast, while wood not, also these-materials have fundamentallydifferent internal-structure. Bamboo-cutting-boards are considered to-be-naturally-anti-microbial; they can be produced, from multiple-pieces, by lamination. Bamboo has long been a-popular-alternative for wood, in-manyareas, not just with cutting-boards. The-biggest-concern, however, is the-sustainability of the-material. Compared to most-woods, bamboo has a-very-fast re-growth-rate, making it ideal for a-range of products. As most-bamboo is sourced in-China, there is an-issue of questionable-labor-practices, and the-energy-spent, to-transport theproduct, cancelling-out the-sustainable-factor. In-terms of cutting-board-quality, bamboo will require somemaintenance, as it can be quite-hard to-the-touch, and is prone-to splitting and cracking.
(iii) Plastic-boards are usually-called PE (polyethylene) cutting-boards, or HDPE (high-densitypolyethylene-plastic), can be made from injection-molded-plastic, or from an-extrusion-line. Polyethylene-cuttingboards have-been-around, for many-years; and proven to-be the-cheapest and effective-types. Most-HDPE-boards are specifically-designed not to-dull the-edge of a-knife. High-density-polyethylene, which is the-most-used in commercial-applications, has been shown to-delaminate, in-response-to knife-scarring (Gkana et al., 2016;Cliver, 2006).
(iv) Marble cutting-boards are known for being one of the-most-hygienic-forms, due-to their-non-porousnature, and ease of cleaning; however, they can do some-damage to the-knives, because of their-tough-surface.
(v) Granite is another visually-pleasing-material-choice for cutting-boards, however such a-board will dull the-knives, and it can be noisy, during food-chopping.
(vi) Maple cutting-board is considered to-be the-most-expensive, on-the-other-hand it will not damage the-knifes, and will help to-prolong its-life significantly. Cleaning a-maple-cutting-board is relatively-simple, and is it non-porous-material, hence fewer-bacteria and less-water can seep through.
(vii) Stainless-steel cutting-boards are not as-common-as the-previously-mentioned-types. Steel-boards are durable and easy to-clean; they do not warp or swell, like some-wood varieties can, and there is no need to-oil them, or perform any-other-maintenance. However, these-boards can damage the-knives significantly and also cause them to-slip, on the-surface, during use. Besides, the-sound of a-knife, against stainless-steel, particularly when chopping quickly, is not pleasant.
(viii) Acrylic cutting-board is cheap and effective, it-is probably be the-second-choice, after polyethene; such a-board can be submerged in-water, or even washed in-the-dishwasher, hence, it-is very-easy to-maintain, however, it should-be sanitized, and replaced every 12 months; making it an-expensive-option.  (ix) Rubber boars are as-expensive-as well-made-wooden-boards, and in-addition they do smell. They can withstand chemical-disinfectants, and they are very-heavy for their-size, so they tend not to-slip. Besides, they exhibit self-healing-properties.
(x) Like-rubber, silicone is soft on the-knife-blade, while being just as self-healing and anti-bacterial, aswood. Silicone is also heat-resistant, and lacks the-rubbery-smell of rubber-boards, but it-is expensive.
(xi) Glass cutting-boards are easily-cleaned and they are more-hygienic, however, they can damage knives, harsh-noises are produced, while in-operation, and due-to their-slick and hard-surface, a-knife can easilyslip, while cutting, and cause a-potential-hazard in-the-kitchen. Also glass-board can be easily broken, especially during washing. In-general, glass-cutting-boards are likely-going-to-do more-harm than good.
Numerous-materials can be used, to-produce chopping-boards; each has its-advantages and limitations. For-example, wood, in-general, is said, to-dull knives, less-than plastic, and plastic is seen as-less-porous, than wood (Cliver, 2006); the-wooden-boards, however, should be-regularly oiled, by edible-mineral-oil, to-avoid warping and splitting. Besides, wooden-cutting-boards do not get cuts, as-deep-as plastic. This means the-bacteria cannot become trapped, and will dry-out, eventually. The USDA's Food-News for Consumers recommended strongly that plastic, not wooden, cutting-boards be used in consumers' kitchens. However, a-study by Ak et al. (1994), indicates, that wood had some-sort of antibacterial-effect, which was not found in-plastic.

Universal-design concept.
Universal-Design (UD) means the-design of products, environments, programs, and services, to-be-usable by allpeople, to the-greatest-extent-possible, without the-need for adaptation or specialized-design (Vanderheiden, 1997). Seventeen-percent of the-U.S.A.-population has some-form of disability (ADA, 2010; Erickson & Lee, 2003), numbers are similar, worldwide; besides, probability of people developing a-disability increases-with-age. As the-population of people with-disabilities grows, so does the-ethical and economic-pressure, to-provide that population with products, which offer services and value. Nevertheless, many-product-designers and companies are unfamiliar-with-approaches to applying UD (a-term, commonly used to-describe goods and services, which are usable both; by persons with-a-disability and by typical-users (McAdams & Kostovich, 2011)). Universaldesign is an-active-research-area; nevertheless, formal-methods for the-design are limited in-scope (Danford, 2003;Preiser & Ostroff (Eds.), 2001;Bowe, 2000). UD is used interchangeably-with Inclusive design (the-term, which mainly-used in the-United-Kingdom (Goodman et al., 2006)), meaning that the-design can be used, equally-well, by people of any-ability: in-other-words, it does not discriminate against users, based on their-ability. In-addition, each of the-Trans-generational, Rehabilitation-design, and Adaptable-design, do share common-elements with UD (Erlandson, 2008;Connell, 1997;Hewer, 1995;Peloquin, 1994).
This-study applies UD-concepts and principles, with particular-emphasis on people with color-blindnesscondition.

Color-blindness-condition.
Color-blindness, also-known-as color-vision-deficiency, is the-decreased-ability to-see color, or to-differentiate colors (to a-certain-degree or completely) (NEI, 2015;Gordon, 1998). Color-blindness does not mean, however, that a-person can only see black and white. Two major-types of color-blindness are: (i) difficulty distinguishing between red and green; and (ii) difficulty distinguishing between blue and yellow. Based on clinical-appearance, color-blindness may be described-as total or partial; while total-color-blindness is much-less-common, than partial-color-blindness (Hoffman, 2008;Spring et al., 2007;Neitz, 2007).
Color-blindness affects a-large-number of individuals, with protanopia (red-deficient: L-cone absent) and deuteranopia (green-deficient: M-cone absent) being the-most-common-types. In-individuals, with Northern-European-ancestry, as-many-as 8 % of men, and 0.4 % of women, experience congenital-color-deficiency (Chan et al., 2014). Likewise, according-to the Howard Hughes Medical Institute, in the-United-States, about 7 % of the male-population, or about 10.5 million men; and 0.4 % of the-female-population either cannot distinguish red from green, or see red and green, differently from how others do (HHMI, 2006). Color-blindness or, color-visiondeficiency, also affects about 2.7 million-people in-Britain. In-Australia, around 8.0% of the-male-population is color-blind, compared-to around 0.4% of the female-population. The-ability to-see color also decreases in old-age.
Being color-blind may make people ineligible for certain-jobs, in-several-countries. This may include being a-pilot, train-driver, traffic-police-officer, and working in-the-armed-forces (NEI, 2015;Wong, 2011). Regardless of the-types, rights of the-color-blind-people have been protected, in-some-states; for-example, according-to the-Decree, issued by president of a-republic, ratifying , of June 13, which approved the Inter-American-Convention AG/RES. 1608, "A Brazilian court ruled that people with color blindness are protected by the Inter-American-Convention on the-Elimination of All-Forms of Discrimination, against Person-with-Disabilities", e.g., the-carriers of color-blindness have a-right of access-to wider-knowledge, or thefull-enjoyment of their-human-condition. In-the-United-States, however, under federal anti-discrimination-laws, such-as "the-Americans with Disabilities Act", color-vision-deficiencies have not yet been found to-constitute adisability, that triggers protection from workplace-discrimination (Larson, 2016;Zhang, 2014).
This-study assumes that color-blindness is a-sort of a-disability; universal-design-approach, to-be-used, to-consider the-condition, by incorporating easy-recognizable-symbols, since colors of the-chopping-boards and cutting-knifes, cannot be distinguished, by the-people with color-blindness.

Materials and Methods.
The-aim of this-research was to-design a-cost-effective, easy-producible, user-friendly, and reliable kitchenutensils-set, that can-be-used to-reduce food-cross-contamination. The-design followed steps of the-fundamental Engineering-Product-Design (see Starovoytova, 2019a;; Figure 4 shows the-chronological-steps,

Examination of available-designs.
A-number of relevant-International-patents (developed by individuals, as-well-as design-companies) were reviewed; examples included: US 9,155.427 B1 (2015)    The-assessment revealed, that: (i) none of the-patents, examined, have featured a-complete-set of colorcoded boards and knifes; (ii) Local-supermarkets, mostly-offered individual-food-chopping-boards (no sets), besides, none had knife-provision; and (iii) Selected-products, available on-line, were pricy, especially for people, in-developing-countries, like Kenya.

Point of Reference for the-design (PRD), and its-limitations.
Following critical-assessment of available-designs, this-study has chosen Joseph Joseph Index™ Color Coded Chopping Boards set, as a-point of reference for the-current-design (due to its-uniqueness and appropriateness, toprevent/limit food-cross-contamination. Joseph Joseph Index™ Color Coded Chopping Boards set, designed by Figure 7 shows contemporary ABS-storage-case with a-non-slip-base; Boards are stored in-staggeredorder, for visual-ease; Illustrated-tabs/labels provide at-a-glance-reminder, which board is which. Besides, theoperational-manual indicates that, boards are dishwasher-safe.

Identified-limitations of the-PRD.
Several-limitations of the-Joseph-Joseph Index™ Color-Coded Chopping-Boards (set of four) were identified (by the-physical-observations and from the-product-users-review-blog), and in-particular: (1) the-boards, inside thecasing, are touching each-other, hence, there could be-cross-contamination from one-board to the-neighboring one(s); (2) no drainage-perforations, at the-bottom of the-set, which could lead-to moisture-accumulation, within the-set; (3) no knife, or knifes, included in the-set; (4) protruding-labels tend to-wear-out and become less-visible (as they are used to-get the-boards out of the-casing), hence, losing its-primary-function; (5) according to Ergonomic-design-principles, pinch-grip, used to-get the-boards from the-casing, is much-weaker than the-powergrip (see Starovoytova, 2018), making the-set un-agronomical; (6) There are no board-handles, hence it-is ratherdifficult to-remove individual-boards, from the-casing; and (7) no provision for a-separate-board, specifically for raw-poultry-meats (according to the-Oxford-Dictionary (2018), poultry is the-inclusive-term for chicken, turkey, and duck-meat, as-well-as pheasants, and other-less-available-fowl).

Generation of the-design-alternatives.
This-study is based on the-major premise, that according-to Gkana et al. (2016): "Separate-cutting-boards and knives, should-be-used, for processing raw-meat and preparing ready-to-eat-foods, in-order-to-enhance foodsafety". In-particular, the-current-design is to-address the-identified-above-limitations, by incorporating: (i) separation-plates, between the-boards, inside the-casing; (ii) perforations, within the-removable-bottom of thecasing; (iii) five-colour-coded-knifes, matching colours of each-of the-five-boards; (iv) a-permanent-labels (engraved) on the-boards, knifes, and the-set-casing; and (v) ergonomically-designed-handle for the-board. Where, Separation-plates (vertical-plates, running-through opposite-sides of the-casing, whereby on one-side they cover the-whole-surface, while on the-other-side they cover halfway, with the-side-left open); Perforations (a-series of small-holes, which cover the-whole-bottom-surface of the-casing); Basement (a-separate-block with acompartment for holding draining-water, which can be attached, or detached, from the-main-casing-interface); Labels (well-embossed-symbols on a-slanted-surface on one-side of the-casing, and on every board and knife); Board withdrawal ( the-boards are laid in-such a-way, that the-handles protrude the-outside-surface, of one-side of the-casing, and their-withdrawal is in-a-horizontal-manner); and Knife-inclusion (the-knives are placed incompartment-block, within the-casing, which has small-open-spaces, upon which the-cutting-blades of the-knives can be inserted).
Several-other-issues were also-taken into-account, during the-design-stage, of this-study. First, it was considered, that any-device usually comprises of various-parts. The-utilitarian or functional-part is the-one that truly-performs basic-task, which prompts the-execution of the-segment. The-non-functional-part does not have real-work in-segment-presence, but rather it needs to-do-with support, spreads, examination, and aesthetical-worth,  Vol.10, No.5, 2019 and therefore, the-number of non-functional-parts should-be-reduced, to-cut the-cost (Juvinall & Marshek, 2012;Budynas-Nisbet, 2008).
Besides, the-designed-set, should be: (i) manufacture-able/easy-producible (using locally-availableequipment and expertise; and being able to-be-easily and effectively-colored, in five-distinct-colors); (ii) costeffective; (iii) soft; and light-weight; (iv) reliable; structurally-sound; and durable. And, as explained above, be functional, hence, components which are not important/functional should-be-eliminated.
Moreover, the-device should-be: Efficient (in reducing food-cross-contamination); Functional (easilymaintained, user-friendly); Pleasant, in-appearance (suitable size and shape, attractive-design, good finishing); Durable (not easily-broken, stable, and robust-design, strong sound-structure); and Safe (harmless to the-user, noside-effects, and environmentally-friendly). To-achieve these-criteria, structurally, all-the-components should: (a) be symmetrical (and have polar-geometry-mark), if possible, as this also-helps in-manufacturing; (b) have consistency, in the-dimensions, used for feeding, orientation, and location; and (c) have location-points ( see Starovoytova, 2019a for more-details).
From the-results of a-study by Adetunji & Isola (2011), it can be concluded that the-cross-contamination, between raw and processed-foods, by-surface-contact is hazardous, because Salmonella can adhere to the-surface, and form a-bio-film, resulting in a-source of contamination. In-addition, a-relatively-recent-study revealed that two-thirds of consumers failed to-adequately-wash hands, after handling raw-chicken, nearly 30 percent failed towash, or change the-cutting-board, after cutting raw-chicken, and one-third failed to-wash, or change a-knife, used to-cut raw-chicken-meat, before cutting raw-vegetables (WHO, 2006;. Salmonella pathogen -is a rod-shaped, Gram-negative facultative-anaerobe, which belongs to the-family Enterobacteriaceae (Barlow & Hall, 2002). To-date, over 2500 Salmonella serotypes have-been-identified, and more-than-half of them belong to Salmonella enterica subsp. enterica, which accounts for the-majority of Salmonella infections in-humans. In-human-infections, the-four different-clinical-manifestations are: (i) enteric-fever, (ii) gastroenteritis, (iii) bacteraemia, and other-extraintestinal-complications, and (iv) chroniccarrier-state (Sheorey & Darby, 2008). Salmonella infection contributes to the-economic-burden of both; industrialized and developing-countries, through the-costs, associated-with surveillance, prevention, and treatment of the-disease (Majowicz et al., 2010;Crump et al. 2004).
The-four-design-alternatives, gnerated by the-design-team, are shown in Figure 8. 3.5. Selection of the-best-design-alternative.
3.6. Description of the best-design-alternative, including its 2D-drawing and 3D-modeling.
Regarding the-dimensions of the-set, the-cutting-board-size acts as the-primary-determinant of the-sizes of othercomponents of the-designed-set; board-dimensions (L x B x T) of 30cm × 20cm × 10mm were chosen (as one of the-most-common-board-sizes, currently used, worldwide).  Figure 9 shows two-dimensional-drawing of the-main elements of the-set, with sizes; Figure 10 demonstrates the-set-assembly of the-best-alternative-design, while Figure 11 shows colour-corded-boards and the-position of labels; Figure 12 and Figure 13 show labels/symbols and dimensions of the-set-components, respectively.   Vol.10, No.5, 2019 Labels (positioned on each-board and each-knife, as-well-as on the-set itself, as an-inclined-panel) were introduced, to-cater for the-people with color-blindness (according to-the-fundamental-principles of the-Universal-design), and also to-avoid-confusion (as a-reminder which board is which, to all-users).

Materials-selection.
The-engineering-materials of mechanical and structural-engineering fall-into the-broad classes/families (Asby, 2010;, such-as: (i) Metals (the-metals and alloys); (ii) Polymers (the-thermoplastics and thermo-sets); (iii) Elastomers (engineering-rubbers, natural and synthetic); (iv) Ceramics, technical-ceramics (Fine-ceramics capable of load-bearing-application), and Ceramics, non-technical (porous-ceramics of construction); (v) Glasses; and (vi) Hybrids (hybrids: composites; hybrids: foams; and hybrids: natural-materials). According-to Ashby (2004), the-very-first-consideration, in-materials-selection, is on the-functionality of the-material; the-main-goal here is being-able to-produce products that function effectively, safely, and atacceptable-cost. The-functionality relates three-aspects, namely: (i) the-function of design-component (what it does), (ii) its-objective (intended-achievement), and (iii) constraints (limits to performance). In-this-study, thefunction of cutting-board is to-aid in-food-chopping-operations, with main-objective being elimination/reduction of food-cross-contamination. The-most-essential (and hence important)-constraint, in the-initial-consideration of materials-selection, in-this-study, is the-ability of a-material to-be-able to-be-dyed/colored in five-solid-colors (socalled 'color-coding'). Besides, a-knife-edge is a-delicate-structure, and can easily-be-blunted by a-surface, which is too-abrasive. A-good-cutting-board-material, hence, should be-relatively-soft, easy to-clean, and non-abrasive, but not fragile, to the-point of being-destroyed. A-good-cutting-board-material should be also less-porous, toprevent moisture-absorption, which facilitate bacteria thrive and cracks. Other-constraints include manufacturability, cost, porosity, health and safety-issues, etc. This-study adopted so-called 'screening'-approach to materials-selection, where (Dobrzanski, 2001) elimination of materials starts by comparing their-attributes and limits, set by constraints, hence, if limits are not met, the-material is eliminated. Only 2 material-suitable-groups of materials were pre-selected, namely: (i) Polymers/'plastic; and (ii) Hybrids: Composites. Afterwards, the-composites-group was eliminated, due-to-lack of composites-manufacturing-equipment and expertise, in-Kenya, leaving the-group of polymer/plastics uncontested.
It-is important to-note, however, that there are over 60 materials in the 'polymer/plastic' group. Figure  14 shows a-comparative-property-chart, for selected-plastic-materials. The-main-properties for comparison, used here, are: cost (should be as-minimum-as possible), moisture-absorption (low), and tensile-strength (high).
From the-chart, it can be observed that polyethylene-materials are superior, based on-cost and moistureabsorption-properties; however, it-is not a-clear-cut, as they are of lower-tensile-strength. The-polyethylenematerials were selected, for further-screening; their-background-information follows.
Polyethylene or polythene (abbreviated PE; IUPAC name polyethene or poly(methylene)) is the-mostcommon-plastic. As of 2017, over 100 million tons of polyethylene-resins are produced, annually, accounting for 34% of the-total-plastics-market. Polyethylene is classified by its-density and branching. Its-mechanical-properties depend-significantly-on variables, such-as: the-extent and type of branching, the-crystal-structure, and themolecular-weight. There are several-types of polyethylene (Kurtz, 2015): (i) Ultra-high-molecular-weight polyethylene (UHMWPE); (ii) Ultra-low-molecular-weight polyethylene (ULMWPE or PE-WAX); (iii) Highmolecular-weight polyethylene (HMWPE); (iv) High-density polyethylene ( PE is usually a-mixture of similar-polymers of ethylene, with various-values of n. Polyethylene is athermoplastic; however, it can become a-thermo-set-plastic, when modified (such as cross-linked-polyethylene). Polyethylene is of low-strength, hardness and rigidity, but has a-high-ductility and impact-strength, as-well-as lowfriction. It shows strong-creep, under persistent-force, which can be reduced by addition of short-fibers. It feels waxy, when touched. The commercial applicability of polyethylene is limited by its-comparably low-melting-point. Higher-crystalinity increases density and mechanical and chemical-stability. Polyethylene absorbs almost no water. The-gas and water-vapor-permeability (only polar-gases) is lower than for most-plastics. In-particular, selecteddata/properties for PE, are: Chemical-formula -(C2H4)n; Density -0.88-0.96 g/cm; ; log P -1.02620 (data are given for materials in their-standard-state (at 25 °C [77 °F], 100 kPa) (Geyer, 2017;Kurtz, 2015;Batra, 2014).
Considering that there are 11 types of polyethylene; the-study recommends to further-investigating which polyethylene-type is the-most-appropriate for this-particular design-set.

Discussion.
As-mentioned-earlier, a-substantial-proportion of food-borne-diseases has been-linked-to poor-food-preparation and hygienic-practices, in-the-home (Redmond & Griffith, 2003). Cutting-boards are recognized as-possiblesources of cross-contamination, with pathogens, as-well-as spoilage-bacteria (Cliver, 2006;Carpentier, 1997). Bacteria may grow, or survive, for a-long-time on cutting-boards, which may subsequently be a-source for contamination of ready-to-eat-foods (Todd et al., 2009). Surveys show inadequate-handling of cutting-boards (lack-of or insufficient-cleaning) for 30-90% of consumers (Redmond & Griffith, 2003). Common-cleaningprocedures, used by consumers, at home, may not be sufficient to-completely remove pathogens from contaminated-cutting-boards (Cogan et al., 2002). According-to the-Food-Protection-Trends (2004), bacteria, on a-cutting-board, can double, after 10 minutes of use, whether cutting raw-meat or vegetables. The-discrepancy, between knowledge and practices, shows that consumer-education is not enough, to-prevent unsafe-practices, and has provided a-market for products with claimed-antimicrobial-activity (Aider, 2010;Marambio-Jones & Hoek, 2010;Monteiro et al., 2009;Moretro et al., 2011;. The-global-antimicrobial-compounds (AMCs)market is estimated-to-be worth USD 3 billion, and projected to-grow to USD 4.5 billion, and 590 kilotons, by 2020 (Grand View Research, 2013). Commercially-available-AMCs can-be-divided (Rosenberg et al., 2019) into: (i) powder-coatings, which can be electro-statically-layered to various-surfaces, and (ii) surface-modificationcoatings, that interact-with application-surface and confer-protection against-pathogens. They can be applied-to surfaces via spraying, draw-down-method, thin-film-coating, and spin-coating (Grand View Research, 2013).
The-antimicrobial-compound may be-incorporated throughout the-materials, or added, as a-coating, on the-surface of the-material. The-antimicrobial-agents can be of organic and inorganic-origin.
For-more-details, on each, of the-listed-above-agents, see Moerman (2013). Hydrogels is the-most-important-family of hydrophilic-adhesion-resistant-coatings. A hydrogel is athree-dimensional (3D) network of hydrophilic-polymers that can swell in-water, and hold a-large-amount of water, while maintaining the-structure, due-to chemical or physical-cross-linking of individual-polymer-chains. By definition, water must constitute at-least 10% of the-total-weight (or volume) for a-material to-be a-hydrogel (Bahram et al., nd;Wichterle & Lím, 1960). There are four-major-categories of polymers and coatings, such-as (Baghdachi et al., 2015): (i) polymeric-coatings, with QA-groups; (ii) polymers with quaternary-phosphoniumgroups; (iii) norfloxacin containing-polymers; and (iv) polymeric-N-Halamines-group.
In-general, the-antibacterial-products are marketed as an-improved-hygiene-barrier. There is growingconcern, however, regarding increased-use of products, containing antimicrobial-compounds, especially in thedomestic-sector. One of the-reasons, behind the-concern, is fear of development of antimicrobial-resistance (Aiello et al., 2007;Gilbert & McBain, 2001Levy, 2001), which is yet to-be-confirmed.
Furthermore, the-results, of this-unfunded concise-study (of preliminary-nature), are largely-relativelypositive, providing a-good-starting-point, for further and much-deeper-study, on the-same. Next-logical-step, would be a-detailed-design, which can-be-generated, using 3D-solid-modeling CAD-programs, such-as SolidWorks. Additionally, according to Ui et al. (2002), the-emphasis of the-design-decisions, unavoidably shiftsaway from technology, towards the-user-interaction-aspects, to-cope with the-new-appreciations of consumers, for the-aesthetic-values of materials. Several-studies, investigated the-relation, between materials and userinteraction-qualities, of products, and how users appraise materials. Selected-studies also-try to-classify the-visual and touch-dimensions of different-materials (see Smith et al., 2008) and, even, the-sound-dimensions, while in operation (see Ui et al., 2002).

Conclusion and Recommendations.
Poor-hygiene, during preparation and/or consumption of food, in-conjunction-with the-ability of food-bornepathogens to-survive (for a-long-time), and also to-multiply, rapidly, can-lead-to food-cross-contamination. Foodcross-contamination, in-turn, can-lead-to food-born-diseases, resulting in-some-cases, in: (a) severe-sickness, or even death (either immediately, or shortly, after food-consumption), or (b) in-increased-risk of chronic-diseases (e.g., Guillan-Barre-syndrome, or rheumatoid-arthritis (CAST)).
This-study has accomplished all-its-objectives, by re-designing the-PRD and incorporating siximportant-upgrading, to-reduce food-cross-contamination, in the-new-product-design. The-study, however, was purely conceptual in-nature; and, hence, it is further-recommends to: (1) carry-out a-detailed-design (by incorporating the-user-interaction-aspects and using more-advanced-methods, such-as PuCC; AHP, and TRIZ, inselection of the-best-design-alternative); (2) select a-specific-material (out of the-group, identified by this-study, via Ashby-charts and matrixes); (3) choose a-mode of fabrication of the-set; (4) examine the-possibility of incorporating of AMCs; (5) fabricate the-prototype(s); (6) conduct explorative-use-ability-trial(s); and (7) analyze the-marketing-aspect of the-final-set.
This-work is potentially-beneficial-to engineering-product-design students and faculty, as-well-as to households and food-establishments (subject-to successful-implementation).

Acknowledgement.
The-author wishes to-acknowledge Kepha Dickson and Yassin Keya, for their-commitment and valuablecontribution to-the-completion and success of this-concise-project, particularly during the-design-stage.