Introduction to Disposable Gloves
Why use disposable gloves? Important for many industries and applications, disposable gloves are a common barrier protectant to help prevent the spread of germs, infections, and environmental contaminants. Disposable gloves are a type of personal protective equipment (PPE) that extends to protective coverings for the face, head, body, and shoes and may extend to masks, head covers or nets, gowns, arm sleeves, shoes and booties.
Disposable gloves provide a chemical and physical barrier between the hands and external environments to reduce the spread of infections, prevent cross contamination, and prevent the exposure to harmful chemicals or environmental contaminants. Of the glove materials, nitrile offers a superior chemical resistance and are recommended for use with the large majority of common chemicals. Disposable gloves help users get a grip in oily or slippery situations where it may be harder to hold small objects or tools.
With the first mention of disposable gloves, latex is often the first glove that comes to mind. In recent years’ nitrile gloves have grown widespread popularity across a variety of applications. From medical facilities, to industrial applications including automotive, food, janitorial and manufacturing to home and personal use, nitrile is the most highly recommended disposable glove material. With advancements in technology, glove variety has expanded to offer many finishes, colors, thicknesses, and textures that have made nitrile gloves both a staple and a chameleon in the field. The wide variety of nitrile glove options available in the market make it easy to find the right nitrile glove for the job.
History of Gloves
How did the common disposable gloves come about? Disposable gloves started with one man’s vision to help his wife prevent rashes on her hands when they were in surgery. In 1889, Dr. William Steward Halstead became the first Surgeon in Chief at the founding Johns Hopkins Hospital. His nurse, and later wife, Caroline Hampton developed rashes from the chemicals she handled for surgery. In search of a solution, Halstead reached out to the Goodyear Rubber Co. to create rubber gloves for her hands. This was such a success that soon his entire surgical staff wore gloves during operations.
Five years later, in 1894 Joseph Lister became the first surgeon to sterilize his surgical tools, dressings and gloves with carbolic acid, a common disinfectant. This development sparked and idea which led to the start of antiseptic surgery practices and the creation of Listerine.
By 1992, with the growing concern of HIV, the Occupational Health and Safety Administration (OSHA) published its Bloodborne Pathogens Standard. This Standard required employers to provide personal protective equipment, including disposable gloves, to employees to avoid contact with bodily fluids. OSHA still requires that gloves are worn in many applications and industries and that is why gloves are worn today.
Up to this point, latex gloves were the primary disposable glove in the market. Latex gloves offer a natural fit and feel with high flexibility and elasticity to conform to the user’s hands. As the use of disposable gloves grew, the demand for latex gloves grew and prices increased. People were in search of a lower cost alternative. This led to the creation of the second generation of gloves, vinyl gloves. This low cost alternative offered a cheaper price point to latex gloves but compromised fit and grip.
During the mid-1990s, the use of disposable gloves became a common staple in every day applications. One of the largest problems was that no glove on the market was compatible with petroleum based products. For this reason, a synthetic material, able to withstand petroleum based products with a stronger overall chemical resistance was introduced. Derived from acrylonitrile and butadiene monomers, nitrile disposable gloves solved the need for higher chemical protection and resistance. Perfect for those with latex allergies, nitrile gloves were highly puncture resistant, latex-free, and offered a snug fit.
Nitrile’s popularity has since grown beyond medical markets and into in industrial markets such as automotive, chemical, safety, and manufacturing. Today, nitrile is used in all industries.
Disposable Glove Materials
Disposable glove materials fall into two broad categories: natural rubber and synthetics.
Natural rubber latex is derived from the Hevea brasiliensis tree native mostly to Southeast Asian countries such as Indonesia, Thailand and Vietnam. Other than disposable gloves, latex is commonly found in products such as balloons, rubber bands, spandex, elastics, erasers, many bandages or adhesives, and many more household products.
Latex gloves are the most habitually used disposable gloves for medical and exam applications. With the best fit and feel, latex provides a durable barrier protection from common chemicals and irritants for the hands.
The downside to latex gloves, some people are naturally sensitive or allergic to latex products. With the use of gloves on a regular basis, for a long period of time, an allergy and sensitivity may develop. A rash known as contact dermatitis is one common symptom of a latex allergy or sensitivity. As the use of latex products grew, the rise of latex allergies became more apparent and the market called for a second generation glove to be made from a low cost synthetic plastic material. The solution was vinyl gloves, made from Polyvinyl Chloride.
Polyvinyl Chloride (PVC) is naturally rigid, perfect for pipes and tubing in its basic form. For gloves, PVC is mixed with a plasticizer to make the material flexible and soft to mold into gloves. This inexpensive material is also used to make shower curtains, bags, aprons, waterproof apparel such as raincoats and rain pants, and many more common household items. Vinyl offers a low cost alternative to latex gloves. With a looser fit, these gloves are perfect for food service or food preparation applications where multiple glove changes are necessary.
Over time, the use of vinyl gloves grew and it became apparent that a suitable alternative to latex was necessary. This led to the creation of the third generation of gloves made from nitrile butadiene rubber.
Nitrile butadiene rubber (NBR), is a copolymer of acrylonitrile and butadiene. This oil-resistant synthetic rubber is used in applications where products may come into contact with hot oils. Such examples include automotive seals, gaskets, fuel hoses and rolls for spreading ink.
Nitrile material offers three times the puncture resistance of latex or vinyl. Further, as body heat warms nitrile gloves, they conform to the fit of the hand for a better, more comfortable fit. This synthetic material is more elastic than vinyl and can be used in a variety of applications such as medical fields, dental offices, manufacturing facilities, janitorial, sanitation and automotive to name a few. Dental offices prefer nitrile gloves when handling and griping sharp tools and instruments. The balance between increased strength and dexterity offers the best barrier protectant for dentists and dental hygienists.
This latex free alternative disposable glove, offers superior chemical resistance to most common chemicals. Nitrile is able to withstand mineral oils, vegetable oils, grease, gasoline, diesel fuel and many acids. In fact, nitrile gloves are recommended for use with 76% of common chemicals on the market. For these reasons, nitrile gloves are recommended for most industries and applications on the market.
Once the glove solution is ready, the manufacturing process is very similar for latex and synthetic disposable gloves.
Before the manufacturing process can officially begin, the ceramic, hand-shaped formers are cleaned and prepared to run down a line the length of a football field. Each line is runs through water and bleach to clean and remove residue from previous runs.
In the creation of synthetic gloves, the formers are first dipped into a mixture of calcium carbonate and calcium nitrate, a solution that helps the synthetically materials coagulate around the formers. Once the formers have completely dried, the formers are dipped into tanks full of NBR or PVC and then heated at a high temperature to form the gloves as they dry. Gloves are dipped multiple times, enough to build the thickness for the finished product.
For easier donning, gloves are finished either by chlorination, polymer coating, powdering, or polyurethane finishes.
The basic material that gloves are made of, whether that is natural rubber latex or a synthetic material, does not naturally allow users to don and doff gloves alone. For this reason, there are number of glove finishes available to facilitate this process. Glove finishes range from powdering, polymer coating, chlorination, and polyurethane finishes.
Powdered gloves, as the name implies, uses a powder coating of food-grade cornstarch to help users don and doff disposable gloves by absorbing excess moisture on the hands. Historically, glove formers were powdered to ease in removing the gloves from the former. For this reason, powder was already on the glove and those that were made free of powder required an extra step to remove excess residue. With advancements in technology, glove formers are no longer powdered. Instead powder is applied to the gloves after manufacturing but before the gloves are removed from their formers.
Powder in gloves is now a preference to the user. There are some situations where powder may interfere with the biological or chemical processes of the application such as chemical sealing or wound closure. Further, the use of powdered gloves in painting or window installation applications is not advised. When powdered gloves are donned, some cornstarch powder particles are released into the air and may introduce a potential source of contamination. In window installation, if powder is caught in the seal of the window it may break the airtight seal. Further, in painting applications, powder may create fish eyes in wet paint and ruin a clean finish when the finish dries.
A more recent finishing option for disposable gloves is applying a polymer coating to the inside of the glove. Manufacturers use polymers such as silicones, acrylics and hydrogels to make gloves easier to don. This coating gives the glove a sleeker finish and reduces the surface friction than the glove material naturally has. The polymer coating is applied to gloves after the manufacturing process while the gloves are still on the former and is most commonly applied to nitrile gloves.
While powdering and polymer coating are commonly applied after the gloves are manufactured, chlorination is a finishing method for powder free gloves that occurs during the manufacturing process. Manufacturers wash the gloves in a chlorine gas or a solution of hydrochloric and hypochlorite acid. After this stage is complete, the gloves are rinsed of the majority of the gas or acid solution. The solutions for the chlorination process reduces the surface tackiness of the gloves by breaking down the material to give it a softer texture. Since this process breaks down the glove material, chlorination also slightly lessens the shelf life of chlorinated gloves.
Latex allergies, are caused by the latex proteins themselves. Originally developed for latex gloves, chlorination reduces the amount of latex proteins, thus lessening the likelihood that the latex will cause an allergy. However, new advancements in technology have made the process available for nitrile gloves as well.
The final glove finish is a polyurethane coating on the inside of the glove that reduces tackiness most commonly for vinyl gloves. The finish is applied to the inside of the glove to make the glove easier to don and doff.
Overall, glove finishes allow users to don and doff gloves with ease. Chlorination makes gloves softer and more comfortable to wear and conform to the hand. Polymer coating adds a sleek finish to the glove to allow them to slip on and off the hand easier. Powder on the glove’s inner surface absorbs excess moisture or sweat. Finally, polyurethane reduces surface tackiness for vinyl gloves.
Glove Quality Testing
Once disposable gloves are completely finished and dried, they undergo rigorous inspection before they are ready for sale and use. For industrial applications that involve harsh chemicals and solvents, disposable gloves must provide enough protection for the hands. Similarly, in medical applications employees need a safe barrier protection against bloodborne pathogens or other bodily fluids.
The first type of glove inspection involves acceptable quality limits (AQL). The United States Food and Drug Administration has set the standard for AQL for medical and exam grade gloves.
AQL testing is also called known as the Pinhole Leak Test. This test determines whether or not gloves are suitable for medical applications. In this test, manufacturers hang the gloves upside-down, fill each glove with one liter of water, and close the gloves at the cuff. Gloves are hung in this position for two minutes to see if the gloves can hold the water. AQL as a testing method allows a certain percentage of a leaks in a batch to occur. For example, a batch of 100 gloves with an AQL of 3.0 will only allow three leaks, or holes that let water through, in that batch to fail the test. If there are more than average of three holes across all the batches tested, the entire batch does not meet the standard. In such instances, manufacturers will review the manufacturing process to determine what requires adjustment.
In the manufacturing process, manufacturing facilities commonly produce medical grade and industrial grade gloves on the same line. This is a cost-efficient way for manufacturers to produce both types of gloves while providing the appropriate level of quality. Industrial grade gloves will pass standard quality testing but are not required to undergo FDA testing with AQL testing for medical purposes. For medical grade gloves, the AQL is 2.5 or lower whereas industrial grade gloves have an AQL of 4.0 or lower.
Some factories run medical grade glove lines only. Then, when batches fail the 2.5 threshold for medical grade gloves but still fall under the 4.0 minimum for industrial gloves, the gloves can be packaged for industrial grade applications.
With these testing requirements completed, the gloves are ready for distribution for sale and use in either medical or industrial applications. Gloves are then packaged and shipped to for distribution across the world. Depending on where gloves are going, factors such as the glove’s color, texture and thickness will vary depending on the specific application the glove is intended for.
Color Variety & Cross Contamination
Disposable gloves are offered in a variety of colors. While some colors are more common to one application versus another, some colors are chosen specifically for certain applications or tasks.
When nitrile gloves first came to the market, they needed a way to differentiate between the nitrile, latex, and vinyl. The first generation glove, latex, by nature is a light ivory, neutral color. Since the creation of latex gloves, popularity of the disposable gloves has grown not only as a barrier protectant, but also with the clean and professional appearance.
Vinyl disposable gloves, are naturally transparent in color – common to the transparent color of shower curtains. Third generation, nitrile disposable gloves were introduced to the market in a light blue color to differentiate among the latex and vinyl proceeded.
In today’s market, nitrile gloves are offered in a large variety of colors. With their high chemical resistance, close and conforming fit, and high puncture resistance nitrile gloves are a staple for a variety of applications in different colors. Automotive technicians, for example, are fond of black nitrile disposable gloves as the color is suitable for rough, dirty tasks where the black color may conceal dirt, grease and grime. Although the color does not alter the usefulness of the glove, the black color is preferred and leads to higher compliance rates.
Orange nitrile gloves offer a high visibility color suitable for a wide variety of tasks. This high visibility color offers similar color protection to high visibility safety gear. Not only is it easier to see the bright orange color in dark working environments, it is also easier for managers to ensure their workers are wearing gloves. Imagine two mechanics are working under the hood of a large vehicle. High visibility disposable gloves allow each worker to easily monitor where their coworker’s hand are at all times to prevent industrial accidents.
Some facilities require additional compliance beyond worker’s preferences. Hazard Analysis and Critical Control Points (HACCP) is a management system of rules and guidelines that control the process and safety in production of food processing facilities. These processes control raw food production, procedure, and handling in addition to the manufacturing and distribution of the finished product.
HACCP regulates the stages of food production to avoid cross contamination. For instance, the first stage may include the cleaning and preparation of raw foods, next stage cooking raw foods, then handling and preparing the cooked foods for packaging, and finally packaging and shipping packaged foods. In this process, each stage will often be clearly identified by a color coded system of personal protective equipment and disposable gloves. In this case, the first stage handling raw foods will wear blue gloves, those cooking will wear green gloves, handing and preparation will wear indigo, and packaging wearing orange. In each circumstance, no worker wearing the wrong color disposable glove, face mask, hair mask, or other personal protective equipment will not be allowed to enter a different section without first properly washing and changing their gear to avoid cross contamination of the production line.
Similarly, color coding will also avoid cross contamination for those with allergies in factories, restaurants and kitchens. In these facilities, those handling vegetables for example will wear green disposable gloves, those handing seafood will wear blue gloves, dairy will wear indigo gloves, and black for meat. More than just gloves, such facilities or kitchens often extend the color code to their knives, cutting boards and such working equipment.
Beyond food processing facilities, color coding is also common in manufacturing facilities with groups of workers rotating shifts throughout the week and workday. In these circumstances, facilities will have groups working on the morning shift outfitted in blue coverings and disposable gloves, those working the afternoon shift will wear green personal protective equipment and disposable gloves and those working the night shift will wear black. This is a common practice for security purposes in manufacturing facilities and processing plants where security of products and processes are high. Color coding workers by specific processes ensures that no employee will know the entire process from beginning to end.
Most commonly, basic color coding gloves is found at most work places where gloves are color coded by size. With small in ivory, medium in green, large in blue, extra-large in black and so on, employees can easily associate their size with a specific color. This allows employees to not take time reading each box when reaching for a glove, a step saved which increases compliance.
Although the Food and Drug Administration (FDA) has not set specific color codes for HACCP, many factories have developed their own color codes.
Wearers of gloves cannot always control the environment, so choosing the right glove for the application is essential. Texture is a key consideration when selecting the right glove for the job.
Nitrile disposable gloves are available in a variety of texture options. The texture for the gloves originates on the formers of the gloves during production. Gloves may be textured on the entire surface, the fingers, the fingertips, the inner palm and fingers of the glove or on both sides of the glove. If a glove is ambidextrous then both sides of the glove are textured.
Smooth gloves do not have any texture on the surface of the glove. This is most common with vinyl gloves. However, smooth nitrile gloves are suitable for applications such as dental, hair care, food preparation and food service. Gloves used in dental applications need to be smooth and comfortable while working inside of a patient’s mouth.
Micro roughened texture is the lightest form of texturing and is most common for nitrile gloves with 95 percent of nitrile gloves offering this texture. This texture gives the appearance of a lightly sanded surface and is suitable for tasks involving grapping small objects or tools. Micro roughened texture is ideal for medical applications with the additional grip to handle tools and small objects without disturbing patients or procedures.
Aggressive texture, or heavy duty texture, is the most intense level of texture offered for disposable gloves. Heavier texture is ideal for gripping small objects that are slippery or wet. For example, in industrial or manufacturing plants, aggressively textured gloves are ideal for gripping small hardware such as bolts and fastening them in place when assembling a large part or machine.
Gloves with aggressive texture such as a raised texture requires more material and thus offers added thickness and protection with both the texture and material enhancements. Aggressive textured gloves are best for industrial applications such as automotive, manufacturing, and industrial industries. They are also offer a stronger grip when working with heavy parts and machinery.
A version of aggressive texture is a raised diamond texture on the surface of the glove. This texture has valleys between each raised diamond that allows liquids to flow through and that enables greater surface contact with the glove, enhancing the grip. This is best for wet or oily working conditions such as in automotive jobs, janitorial and sanitation and industrial facilities. Raised diamond pattern textures are also applied to aluminum, steel plate and rubber floor coverings, stair treads and walkways for slip resistant surfaces.
Similar to the variety of color options and glove textures, glove thicknesses vary wildly depending on the task at hand.
Glove thickness is determined in the manufacturing process. When gloves are made, ceramic glove formers are positioned on the assembly line fingers downwards. As the formers move along the assembly line, gravity pulls the solution down towards the bottom of the glove. After the gloves are completely dried the fingers will be the thickest part of the glove while the wrists will be the thinnest. Conveniently, in most applications disposable gloves have the most wear and tear on the fingers. Thus, the slightly thicker part of the glove will be able to withstand the added use.
Other than gravity, glove thickness is built by dipping the formers into the solution more times. Each time the forms are dipped, an additional layer of solution is spread over the previous layer. Therefore, the more times a glove is dipped, the thicker the final glove.
Some glove manufacturers use calcium carbonate as a filler to reduce the content of the raw material in a nitrile glove. Calcium carbonate is one of the most popular fillers used in the plastics industry. The addition of the filler allows the manufacturer to use less raw material, produce more in the same batch and offer each plastic product at a lower price. This filler helps to provide a glossy finish to the plastic and create a smooth finish. In the right amount, calcium carbonate will increase the strength and stiffness of the plastic.
In disposable gloves, calcium carbonate will make the glove feel thicker and will measure in mils as a thicker glove just as if the raw material was built up to the same thickness. In the most basic sense, the calcium carbonate filler is similar to adding chalk to the glove. While this may help users don and doff the gloves with more ease, the integrity of the raw material NBR is compromised with the addition of the filler.
In the application and use of disposable gloves, there is a direct correlation between thickness, material and chemical resistance. The thicker the glove, the stronger the chemical resistance to harsh chemicals that would naturally break down the glove’s material. Chemical and lab settings, for example, require thicker gloves for more protection to the users. In turn, the dexterity needed for these applications is much less so the tradeoff between stronger chemical resistances of thicker gloves works out in favor of the task.
On the other hand, tasks such as medical or dental procedures require high tactile sensitivity and dexterity. Users will need to feel through the gloves and have full range of motion of each finger to complete their tasks. For this reason, the tradeoff between dexterity and chemical resistance is made in favor of dexterity. Thus thinner, more nimble gloves are best for these situations.
Glove thickness factors into the price of the glove; the more material used to build the thickness of the glove, the more expensive the cost to make. Applications such as food service and food processing require lightweight gloves are best for short-duration tasks where glove changes occur often. Not only are the lightweight gloves more efficient to slip on and off quickly between tasks, they are cheaper overall.
In the past, vinyl gloves were commonly the cheapest, lightweight glove available on the market. With the advancement of technology and formulas, lighter weight nitrile gloves have been introduced to the market. Lightweight nitrile gloves offer high tactile sensitivity and dexterity with the added benefits of enhanced chemical resistance and puncture resistance as compared to vinyl or latex.
For any intended use, it is crucial to conduct on-site testing with any glove set for use in an application. Testing will determine how workers can protect themselves and the policies for length of time workers are exposed to a chemical or solution before a glove change is required. In basic chemical resistance tests, glove materials are tested for resistance to one chemical but not against the specific mixtures used in unique or specific applications.
In chemical testing, glove materials are rated on their ability to withstand exposure to a certain chemical. The two factors that are measured are degradation and breakthrough time. As a glove degrades it may change color, swell, wrinkle, or get stiff. Degradation will determine whether a glove is a good fit for a specific application. Breakthrough time is the length of time between the initial contact with a chemical and when the residue is detected on the inner side of the glove. This test indicates how long workers are able to safety wear the glove as a barrier protectant. Finally, permeation is the way a chemical passes through a material on a molecular level.
Overall, nitrile gloves offer superior chemical resistance against common chemicals as well as many specialty chemicals such as water treatment chemicals or industrial cleaning compounds. Nitrile gloves are best for applications in automotive industries where petroleum derivatives such as gasoline and brake fluid are common to daily tasks.
Initially the rise of latex allergies led to the creation of synthetic disposable glove materials. While the most common glove allergy and/or sensitivity is to latex gloves, there are some people that experience reactions to the synthetic glove materials. However, rather than the material itself, users often reach to the chemicals used in the production process to make the gloves. For example, some people are allergic to petroleum, a chemical used during the production process for nitrile and vinyl gloves.
With any product, repeated exposure and long duration of use may create allergies or sensitivities in some individuals. With the rise of synthetic gloves, sensitivities to the accelerator used to speed up the drying phase of manufacturing are growing. Accelerators, such as carbonate and thiurams, are specifically used to speed the linking of molecules in latex or synthetic materials. These chemicals help to stabilize the material. It is believed that sulfur-based chemical accelerators cause the majority of skin dermatitis reactions, also known as skin sensitivities or rashes.
Alternatively, the most common cause of irritation with disposable gloves is a substance or solution that is applied to the hands before gloves are donned. Some substances, such as hand soap or a scented lotion will not cause problems to the hand alone but instead will create an issue when they are pressed into the hand when a glove is worn.
Although unusual, the most common circumstance for this occurrence is when users both apply product to the hand before the gloves are donned and the size of the glove used is too small. Gloves that are too tight may cause discomfort and irritation as the skin is unable to breathe inside the glove.
Although disposable gloves were first developed for the medical industry, in recent decades attention has expanded to safety and protection in industrial markets such as automotive, food processing, food service, janitorial and sanitation.
When it comes to making the best glove selection among the many disposable gloves on the market today, it is crucial to consider the intended use. First, gloves that may come in contact with bloodborne pathogens or other bodily fluids must meet FDA standards for medical grade gloves with an AQL of 2.5 or lower. Disposable gloves for all other purposes fall into the industrial grade category, a less stringent set of requirements that still meet factory standards.
Next, the intended use will determine which material is best for the job. If repeated gloves changes are necessary, such as food service or sandwich shops where a new glove is required for each customer, a lighter weight glove is best. Further, with frequent glove changes vinyl gloves are the best low cost barrier protection.
Nitrile and latex gloves offer a more conforming fit that will provide greater dexterity and tactile sensitivity. Nitrile provides the strongest chemical resistance of all glove materials and is a latex free alternative perfect for users with latex allergies. With the superior chemical resistance, nitrile offers protection against petroleum based products such as gasoline or oil along with protection against most common chemicals on the market.
If compliance is concern, then choosing a color that best suits the wears and/or the application may influence the decision. Orange nitrile gloves offer a high visibility orange hue that can be seen even in low light conditions. Black nitrile gloves offer a bold color that may conceal dirt, grease and grime in automotive or industrial applications. Ivory latex gloves provide a clean finish suitable for medical, dental, or examination applications.
In other situations, it is important to consider the glove finish. If working in a clean room or car detailing, then powder free gloves are essential to limit the added particles in the air from donning or wearing gloves. Alternatively, if wearing the gloves for an extended period of time, powder in gloves will absorb excess moisture on the hands. Further, polymer coated gloves offer a sleek finish to help the glove slip on, chlorinated gloves offer a softer texture but limit the shelf life.
Glove texture will either lessen the surface friction or enhance the grip. Micro roughened texture, which is offered on 95% of the gloves on the market is ideal for applications with additional grip to handle tools and small objects without disturbing patients or procedures. Aggressive texture is best for applications that need added surface contact and a stronger grip. Raised diamond texture creates and even stronger grip in wet or oily conditions as more liquid can pass through the texture’s channels.
The thickness of the glove will increase the chemical resistance with added material but will decrease the tactile sensitivity and flexibility. The thicker the glove the less nimble and less dexterity that will be offered. Glove thickness is crucial in applications working with harsh chemicals for an extended duration.
All in all, users cannot always control the environment so choosing the right glove for the application is essential.