Glove-Associated Reactions and Barrier Preservation in the Cleanroom
It is important to recognize that many methods used to alleviate symptoms of glove-related reactions may actually destroy glove-barrier integrity, placing the wearer at risk and potentially compromising the cleanroom environment.
BY Dr. Wava M. Truscott and Lorraine Roley
A quality glove can only be identified after observing it from a number of perspectives. In the cleanroom, a good glove provides protection for work-in-progress from particles, oils, chemicals, microorganisms, endotoxins or any other contaminants as defined by the product`s requirements. In addition to providing adequate protection for products and processes, quality gloves must protect the wearer from processing agents in manufacturing and microorganisms in the laboratory.7,8 The industrial health nurse or hygienist further defines a quality glove as one that does not cause glove-associated reactions to develop despite years of daily use. The sum of these expectations should provide the criteria to evaluate candidate gloves. To ensure expected performance, proper glove storage and in-use practices must be exercised.
Much has been written about glove requirements as they pertain to work-in-progress. Particle sizing, in-use surface shedding, and chemical extraction analysis evaluation have defined tighter boundaries of acceptable performance. This article shall instead address the additional requirements imposed by employees and industrial health. Clinical and scientific information will also be presented with recommendations for practical application.
Glove-associated Reactions
There is a great deal of concern regarding the escalating number of reported glove-associated reactions in the healthcare profession.1 Although the same types of reactions occur in the cleanroom industry, they do so with less frequency. This is primarily due to the extensive post-production processing that gloves are subjected to render them compatible in the cleanroom environment. It is, however, critical to be able to differentiate between the reactions, isolate the causative agents, and take appropriate actions to alleviate any reactions that may arise. Inappropriate actions may result in contaminated work, persistent employee discomfort, and in rare cases, may be life threatening.
Although there are only three primary reactions associated with the use of gloves, the multitude of terms used to identify them can often be confusing. It may be most useful to summarize them.
Irritation: Irritant contact dermatitis; Non-allergic contact dermatitis.
Allergic contact dermatitis: Delayed type hypersensitivity; Type IV hypersensitivity; Chemical allergy.
Immediate type hypersensitivity: Type I hypersensitivity; Protein allergy; Urticaria; Asthma; Anaphylaxis.
These adverse reactions can be distinguished by their clinical features and the agents that cause them. See “Reaction Profile” for a list of reaction characteristics for reference.
Irritation
All individuals are susceptible to irritation. It occurs as a result of direct or indirect cell injury. The first symptoms to appear are usually redness with associated itching or burning. These acute symptoms may develop into a rash after repeated or prolonged contact with the source of irritation. More intense symptoms may develop wherever the glove is especially tight or imparts repetitive friction, such as at the knuckles, back of the hands or at the wrists. Extensive exposure leads to the onset of chronic symptoms characterized by dry, thickened skin, cracking, and papules (small, hard, raised bumps). Symptoms of an irritation occur within minutes to hours after exposure to irritants; they do not appear beyond the contact area of the glove.16
Irritation may be caused by either synthetic or latex gloves. The use of excessive or irritating chemicals, inadequate or poor leach conditions, or insufficient post-processing may result in gloves that cause irritation.
Although infrequently found in cleanroom environments, ancillary functions may use powdered gloves. Glove powder is often implicated in irritation by first absorbing the intracellular lipids, increasing cell vulnerability, and then by abrading the unprotected cells. The combined activities result in dry, irritated hands.
Glove-related irritation may require switching to an alternate manufacturer or merely another lot of the same gloves. Powder-free gloves will eliminate irritant reactions when they are related to powder. If at all possible, frequent glove changes are recommended. This allows the skin to air and dry, if only briefly. If work conditions permit, a larger glove will allow increased air circulation and reduced friction during healing. Anti-inflammatory agents may be helpful, but caution must be exercised as oil-based lotions and medications degrade latex and several synthetic glove materials. Cotton or nylon liners have proven helpful for a number of individuals with irritation. However, as with all actions, the use of liners must first be evaluated for the potential work interference or contamination prior to their use.
Investigating Irritant Causes
While investigating the cause of an irritation, nonglove-related irritants should be suspected first. Because of the occlusion, hyperhydration and heat retention caused by long-term glove use, the skin becomes more permeable to substances, thereby allowing the reactions to minor irritants to become magnified. For instance, hands that are insufficiently rinsed of soap residue may show no signs of irritation when aired in normal environmental conditions, such as overnight or throughout the weekend. However, they may produce an “angry” inflammatory irritation after several hours on the job due to the enhanced dermal penetration and occlusive conditions created by extensive glove use. If such a condition is encountered, more extensive rinsing or a mild soap should be recommended.5, 9
Additionally, substances may penetrate the glove and cause irritant reactions, magnified in intensity by the occlusion. For example, most chemicals such as solvents, alcohols, petroleum products, acids, and caustics used for a multitude of industrial activities will eventually permeate most gloves. Permeation rates depend on chemical concentrations, temperature, type of contact (e.g. intermittent splash, emersion), composition and thickness of the glove material. Glove compatibility may be re-evaluated if there are variations in any of these parameters.
For mildly offensive chemicals, a simple evaluation of glove degradation over time may be sufficient. Indicators of degradation include glove softening, brittleness, finger elongation or “creep,” increased transparency, loss of strength, and loss of elasticity. If the glove degrades within the routine chemical contact period, it may be necessary to change gloves more frequently, double glove, or decrease chemical contact time.
Hazardous chemicals require more sophisticated methods of permeation analysis and should only be undertaken by individuals trained for such procedures.
Allergic Contact Dermatitis
While irritation is a local inflammatory response to injury, allergic contact dermatitis is an allergic reaction to specific chemicals identified as contact sensitizers.5,12 When a genetically susceptible person is repeatedly exposed to a chemical contact sensitizer, the body produces sensitized T-cells. This phase, called sensitization, is asymptomatic–although the body is increasing the number of the chemical specific T-cells, the individual experiences no symptoms. Eventually a critical level is reached and subsequent exposure to the offending chemical will elicit physical symptoms. At this point, the individual is said to be sensitized, or allergic, to the offending contact sensitizer (antigen.)
Initial symptoms usually include redness. Tiny clustered blisters may appear after several hours, which elicit pain when scratched. After prolonged, repeated exposure to the chemical, a more chronic condition may develop with dry and thickened skin, cracking, peeling, sores and papules.
The appearance of allergic contact dermatitis may easily be confused with irritation. However, allergic contact dermatitis is unique in that it normally requires six to 48 hours after exposure to the attending chemical before the most intense level of symptoms appear (hence the term “delayed-type hypersensitivity”). Another distinguishing characteristic is that allergic contact dermatitis will eventually extend up the arm, beyond the boundary of glove. Allergic contact dermatitis can occur anywhere the chemical contact sensitizer touches the body, even if contact is brief.16
Contact sensitizers are found in both latex and synthetic gloves. The additives most frequently associated with reactions are the chemicals known as accelerators. These chemicals function as catalysts, facilitating particle bonding and are essential to the manufacture of most elastomeric products. Fortunately, there are only three basic categories of accelerators (thiurams, mercaptobenzothiazols and carbamates) utilized in varying amounts and combinations by different manufacturers. Approximately 15 to 25 percent of the glove-related cases of allergic contact dermatitis are caused by contact sensitizers other than accelerators. These potential contact sensitizers include antioxidants, colorants, preservatives, resins (in synthetic gloves) and plasticizers. Isolation of the chemical responsible for an individual`s allergic contact dermatitis is by patch testing conducted by a dermatologist. Alternatively, information supplied by the manufacturer may be sufficient to identify the causative agent. Once the accelerator responsible for an individual`s reaction is identified by a dermatologist, alternate gloves utilizing a different accelerator mix or those with reduced levels may be substituted.
Gloves with a hypoallergenic label were developed to address the needs of individuals who experience either irritant or allergic contact dermatitis. These gloves are formulated and/or processed to minimize the level of residual chemicals in general, and contact sensitizers specifically. 10,15 Hypoallergenic gloves should eliminate either form of dermatitis. On the preventative side, if individuals prone to dermatitis from other products utilize hypoallergenic gloves exclusively as they initiate their career, they may avoid not only having reactions, but also becoming sensitized.
Except for a few reported cases, glove powder does not cause allergic contact dermatitis. However, once powder is placed on the glove during production, chemicals from the glove adhere to the particle surface. The powder then functions as a carrier, transporting the chemicals in the air and onto surfaces.2,3,14 Chemicals from gloves and those used in the work place adhere to and are transported by powder particles. Inhalation of the powder may aggravate or potentially sensitize susceptible individuals.
Immediate-Type Hypersensitivity
Immediate-type hypersensitivity (Type I) is also an allergic condition. However, unlike allergic contact dermatitis, the sensitization process involves increasing the number of specific IgE antibodies and mast cells rather than T-cells. The responsible allergens in latex gloves are the proteins in natural rubber latex. They originate from the rubber tree, Hevea braziliensis. Repeated exposure to these allergens increase the asymptomatic level of sensitization in genetically predisposed individuals until a threshold level is reached. Subsequent exposure may result in any of several clinical symptoms including itching, tingling, hives (which may spread over the entire body), swelling of the lips or eyes, runny nose, watery eyes, congestion, tightening of the throat, abdominal cramping, headaches or asthma. Reactions may occur within seconds to an hour after allergen exposure. Severe reactions, characterized by generalized swelling, a profound drop in blood pressure and sudden increase in heart rate, may result in full anaphylactic shock. This condition can be life-threatening and requires immediate emergency medical attention. (See “Risk for Immediate Type Hypersensitivity to Natural Rubber Latex,” p. 28).1,5,6
The prevalence of routinely gloved personnel in industrial positions has yet to be established. Atopy appears to be an added risk factor; approximately 75 percent of sensitized individuals have a history of atopy. Because of the extremely high susceptibility of spina bifida children, all should be considered latex sensitive as a precautionary measure.
Sensitization is dose and rate dependent. Because the latex protein level on gloves from different manufacturers varies by orders of magnitude, it is extremely important to select gloves low in protein allergens. This will minimize the potential for developing an immediate-type hypersensitivity to latex. Caution: Individuals already sensitized, must wear synthetic gloves. The inhalation of latex proteins via powder is a threat to the sensitized worker.2,3,13,14 To prevent inhalation of latex protein-laden powder by sensitized individuals, co-workers should wear powder-free gloves. Sensitized individuals should wear emergency identification specifying a latex allergy and should obtain a prescription for Epi Pen® or other source of epinephrine from their allergist. Personnel must be trained to recognize and respond appropriately to potential anaphylactic shock conditions.
Barrier Preservation: Lotion Compatibility
Individuals suffering from irritant or allergic contact dermatitis often seek the relief of lotions and anti-inflammatory ointments. Latex, as well as several synthetic materials are degraded by a number of oil-based lotions such as mineral, coconut, palm, petroleum gels and salves, jojoba and lanolin.11,17 These ingredients act as plasticizers, disrupting bonds through chemo-mechanical means, resulting in degradation. Although a handcare regimen incorporating these ingredients is encouraged away from work, only latex-compatible lotions should be worn under gloves. Alternatives include lotions formulated with a water, glycerin or any other non-oil base, and the use of lotion at the workstation should comply with company policies.
To assess the potential degradative properties of a particular lotion, the following simple experiment may be performed. Cut equal strips from the palm or back surface of the glove, approximately 0.25 ¥ 2 in. Stretch and secure the strips at approximately 3¥ their length. Coat one heavily with the lotion in question. Leave the other uncoated as a control. After 30 minutes, release the strips and place them side by side. If the lotion-treated sample has enlarged either in length or width, the mechanical stability has been degraded and the lotion is unacceptable.
To reduce the risk of puncture, jewelry should be removed prior to donning gloves. Removing jewelry will also permit less obstructed washing and rinsing.
Composition
Latex gloves have set and maintained the standard for barrier durability. Choose glove materials carefully. Vinyl, for instance, does not have the strength, elongation potential, or flexibility of latex. It breaks rather than gives. This is apparent at the microscopic and macroscopic levels, particularly between fingers and at the fingertips during strenuous, friction creating and torquing manipulations.7,8 If other glove materials are being considered, it is strongly recommended that evaluations include durability assessments. After the completion of routine gloved procedures, fill the used gloves with water and observe for leaks. Such studies should only be conducted utilizing appropriate, contamination controls where necessary (e.g., diagnostic laboratories).
Storage
Proper storage conditions are extremely important in the preservation of glove barrier integrity. Prolonged heat, excessive moisture and intense light are all detrimental to glove materials. Ozone, created by electrical equipment such as fans, generators, X-ray machines, and fluorescent lights, alters the molecular structure of the glove, resulting in broken chemical bonds that weaken the material`s strength.4 This phenomenon is most readily seen in the folds or creases of ozone-subjected gloves, where tension caused by the fold increases the energy available to speed the degradative process. The resulting ozonation often appears as a perforation line. It is critical that gloves be stored away from generators, X-ray machines and other sources of ozone generation.
Minimizing Risk
When evaluating gloves for cleanroom use, one must look beyond the standard product contact requirements that include particle levels and surface chemical specifications to factors that may affect employee health. It is essential that the staff industrial hygienist be able to identify and manage glove-related reactions that staff may experience. To minimize the risk of personnel developing any of the three conditions, utilize quality gloves low in chemical additives and protein allergens. After gloves are selected, they must be stored and worn properly to prevent degradation and loss of barrier integrity. Adjustments to gloving protocols may be required as working conditions, personnel, chemical contact or glove material change, and compatibility evaluations are performed.n
For a list of references used in this story, please contract CleanRooms magazine at (603) 891-9230.
Dr. Wava M. Truscott has an extensive background in the glove manufacturing industry, specifically with barrier integrity, biocompatibility, and sensitization as it relates to reactions and claims-substantiation issues. In her current role as vice president of scientific affairs for Safeskin Corp. (San Diego, CA), Dr. Truscott is directly responsible for the scientific-related actions of the corporation, the coordination of contract lab testing, writing of technical bulletins, and promotional approval. Her duties also include product research and development, educational services, technical complaint resolutions, FDA submissions, claims review, and the development of technical services information and assistance. She received her Ph.D. in comparative pathology from the University of California at Davis, her MBA from the University of La- Verne and her BS in botany from Brigham Young University.
Lorraine Roley is the senior research associate for Safeskin Corp. Her background encompasses both a clinical history as well as research in the biotechnical arena, with an emphasis on immunology. Roley received her BA in biology and chemistry from Salve Regina University in Newport, RI, and her MA in human behavior form the United States International University in San Diego, CA.
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Hands infected with irritant contact dermatitis can be treated with anti-inflammatory medication.