Selecting the Right Laboratory Coat
BY DEREK A. NEWCOMER, JULIANNE L. BARON, AND DAVID MARTINSON
The Last Line
OF DEFENSE
Industrial hygiene practitioners are often consulted to recommend personal protective equipment (PPE) as a control strategy to minimize worker exposure to biological, chemical, and physical hazards. Although the use of PPE is considered the last line of defense against these hazards, its ease of use and general availability makes it a default choice for some workplaces. Ideally, engineering controls should be used as primary barriers, functioning to contain the hazards. When necessary, the use of PPE can augment engineering and administrative controls to reduce the risk of worker exposure to workplace hazards.
In some locations, PPE is part of the required uniform attire. Research facilities, for example, are associated with scientists wearing laboratory coats.
When selecting laboratory coats, the industrial hygienist is concerned with limitations of dexterity, durability, employee comfort, and compatibility with the hazard of concern. These and other criteria provide the framework for an organization’s PPE program. While dexterity, durability, and employee comfort are subjective, material compatibility is objectively derived from analytical testing. Laboratory coats may appear similar in style and color, but some scientists may be surprised to discover that there is no universal laboratory coat suitable for protection from all laboratory hazards.
LIMITED PROTECTION
Traditional white laboratory coats, which are made of 100 percent cotton or a polyester/cotton blend, are widely used. They can protect against limited splashes and spills of non-hazardous materials, but they don’t offer adequate protection when the wearer is working with infectious materials, chemicals, or flammable or pyrophoric liquids. For example, chemicals that are pyrophoric, spontaneously combustible, or extremely flammable present an especially high risk for fire and burns to the skin. For researchers working with these chemicals, a flame-resistant or fire-retardant laboratory coat is appropriate. However, a flame-resistant laboratory coat should not be worn when working with strong acids, oxidizers, or reducers because these agents can react with the garment’s flame-resistant polymer. Researchers working with chemicals should wear a laboratory coat that provides appropriate protection for the chemical in use. Unfortunately, many chemical protective laboratory coats are flammable, which further complicates selection of the right garment.
The protection afforded by an appropriate laboratory coat is limited if it isn’t worn properly. Closures and seams should be considered when selecting a laboratory coat because these openings, if they aren’t sealed or double stitched, may serve as entry points for hazardous materials onto the worker. Indeed, a laboratory coat is not a coverall; additional appropriate clothing is necessary to cover and protect the lower extremities in the event of a spill. Tights or other thin materials are not recommended because they don’t provide proper dermal protection. For these reasons, personnel should wear appropriate clothing that prevents direct contact of the hazard with the skin. Examples of appropriate attire include long pants or leggings and closed-toe shoes. Synthetic fabrics that could melt against the skin in the presence of high temperatures should be avoided when working around flammables.
RISK ASSESSMENT
OSHA’s bloodborne pathogens and occupational exposure to hazardous chemicals in laboratories standards apply to research settings where personnel are working with chemical and biological agents. When there is risk of occupational exposure to bloodborne pathogens, OSHA requires that the employer provide appropriate PPE, such as laboratory coats. In other instances, the need for laboratory coats is predicated on a task-specific risk assessment.
OSHA’s PPE standard mandates that the employer assess the workplace to determine if hazards are present or likely to be present. A risk assessment should be performed to determine the hazards associated with a particular laboratory or laboratory operation and establish which engineering control should be used and what PPE should be selected. In the absence of a documented risk assessment or appropriate use of PPE, scientists are at risk for exposure to the hazardous substance, which could cause injury.
The hierarchy of controls states that when evaluating the work environment, the employer should substitute a less toxic material for the hazard. If this isn’t practical, engineering controls should be incorporated into the process. In laboratories, chemical fume hoods and biological safety cabinets serve as primary barriers between the hazard and employee. Although such engineering controls minimize inhalation exposures, these devices are not adequate to protect the employee from splashes or spills. If a chemical or biological material is spilled or splashed in the vicinity of the employee, the laboratory coat impedes dermal contact with the hazardous material.
A written certification documents the occupational risks for each work location. If hazards are recognized, then measures must be implemented to minimize exposure. The risk management approach is applicable to many operations, although some industries have inherent hazards that, for financial or technical reasons, cannot be substituted for or engineered out of the process. In these cases, the only option is to minimize the chance of exposure between the hazard and employee through the use of PPE.
LABORATORY COAT TEST METHODS
On May 1, 2016, the newsmagazine television program 60 Minutes aired an investigative report titled “Strike-through” that described the sale of defective PPE during the 2014 Ebola virus disease outbreak in West Africa. To support these allegations, 60 Minutes
showed laboratory test results indicating protective gowns were susceptible to passage or strikethrough of bloodborne pathogens.
A risk assessment should be performed to determine the hazards associated with a particular laboratory or laboratory operation.
The
60 Minutes
news story is a reminder that the physical and chemical limitations of PPE are often determined through analytical techniques. Guiding the testing and verification of PPE are methods issued by nationally recognized standards organizations. Because not all laboratory coats are tested, industrial hygienists should consult with the manufacturer prior to recommending a certain coat. Following are a few things to consider when consulting with manufacturers:- Testing laboratory coats for protection against chemical, physical, and biological hazards is at the discretion of the manufacturer.
- Manufacturing changes can affect the protective integrity of the coat. Results of material testing represent only the product tested. The product should be retested if the manufacturer makes process changes. Similarly, good quality assurance practices would dictate periodic retesting regardless of production changes at the manufacturing facility.
- Test methods are specific to individual chemicals or classes of similar chemicals. A laboratory coat advertised as resistant to chemical spills and splashes will not provide universal protection against all chemicals.
The possibility for reuse or laundering of a laboratory coat depends greatly on the material composition. If a laboratory coat is coated with a material such as polyethylene, laundering will erode the protective coating and result in diminished protection.
RECENT LABORATORY ACCIDENTS
In recent years there has been a string of high profile laboratory accidents at U.S. institutions including Texas Tech University, University of Hawaii, and University of California, Los Angeles (UCLA). Some of these incidents were severe enough to cause significant property damage or even death. Reports on several of these accidents specifically mention laboratory coats.
In the University of Hawaii case, a researcher lost an arm in an explosion that probably resulted from accidental ignition of gases that were being mixed in an ungrounded container. An investigation found that the researcher’s notes indicated that she had asked a number of safety-related questions prior to the incident, including whether she would need a flame-proof lab coat. No answer to this question was recorded in the notes. Although a laboratory coat would not have prevented this incident, a post-accident report notes the importance of flame-resistant laboratory coats when working with a highly flammable gas and that researchers can underestimate the necessity of PPE when they don’t appreciate the hazards present.
At UCLA, a researcher was severely burned, and later died, from ignition of a pyrophoric compound. The researcher wasn’t wearing a lab coat, and her synthetic sweater caught on fire and melted onto her skin. A flame-resistant laboratory coat should have prevented the ignition of the researcher’s clothing.
Not all recent laboratory accidents have been as serious as these, but they nonetheless highlight the necessity for proper laboratory coats. A graduate student at Northwestern University, for example, described an incident in which he was burned on the arm by triflic acid. He noted that if he had been wearing his laboratory coat the acid wouldn’t have contacted his skin.
Not surprisingly, these incidents aren’t restricted to colleges and universities. Several newsworthy laboratory accidents have occurred in high school chemistry classes and demonstrations over the past 10 years. Some have led to large explosions and sent numerous students to the hospital for severe burns. These incidents have drawn so much attention that the U.S. Chemical Safety Board (CSB) issued a report, “Key Lessons for Preventing Incidents from Flammable Chemicals in Educational Demonstrations,” that notes the importance of performing a hazard review, detailing safety precautions, and utilizing appropriate PPE including “lab coats or clothing made of flame-resistant material.” CSB cites an incident from 2006 in which a high school student was burned over 40 percent of her body during a chemistry demonstration. In 2013, the former student was interviewed for a video produced for CSB in which she states that she believes the accident was entirely preventable and specifies a “lack of safety gear” as a contributing factor to her injury.
RECOMMENDATIONS
A complete risk assessment should be performed prior to initiation of any laboratory research. The risk assessment should determine associated hazards and necessary mitigation strategies. Since not all hazards can be predetermined, the risk assessment should be reevaluated through the life of the research project.
Training, including on the use, limitations, and proper wear of laboratory coats, should be provided for all employees. This approach to personal protection depends on employees properly wearing and maintaining the PPE, and their willingness to don the laboratory coat when working with chemical, biological, and physical hazards. The employees’ decision to wear protective equipment is often related to their personal perception of risk. Prevention programs that focus only on the use of PPE are dependent on human behavior and should be supplemented with written PPE policies where employees gain additional knowledge about the importance of PPE and institutional PPE requirements, and become more actively involved in their own safety.
The author Stephen Covey is quoted as saying, “accountability breeds response-ability.” In the realm of personal accountability, we are all responsible for ensuring we maintain workplace safety. However, in most research settings the principal investigator is held directly accountable for personnel safety. Ultimately, the accountability should extend upward in the institution all the way to the organizational leader. In reality, a combination of individual responsibility, in addition to organizational accountability, may be the better approach to enforcing policies on worker protection than a dependence on individual human behavior alone.
Laboratory coats should be inspected for defects prior to use to ensure that there are no holes, rips, or tears that could allow hazardous substances to enter the coat and come into contact with the person wearing it. If defects are found, the laboratory coat should be disposed of appropriately in accordance with the hazards present. The material compatibility of laboratory coats should be verified prior to use by third-party analysis. Laboratory coats should never be worn in areas where food is stored or consumed. Indeed, all PPE must be removed prior to exiting the laboratory into shared common spaces to prevent contamination of clean spaces. Laboratory coats should never be taken home to launder.
POTENTIAL FOR PROTECTION
The hierarchy of controls provides guidance on injury and infection prevention by describing measures to address the potential for exposure to hazardous substances. The use of PPE is the least preferred technique, although it is warranted under certain circumstances—for example, when elimination of the hazard is not technically feasible. For PPE to be effective, it must be appropriate for the hazard at hand, fitted properly, be in good repair, and—most importantly—be worn correctly by the employee.
Specific to the use of laboratory coats, the style and composition must be considered. Laboratory coats composed of natural and synthetic materials offer varying degrees of protection to chemical and biological agents. Although not mandated by law, test methods are available to ensure the selected laboratory coat is suitable for the anticipated hazards. Not all manufacturers subject their product to integrity tests; therefore, industrial hygienists should ensure the selected laboratory coat is protective for the working environment.
CDR DEREK NEWCOMER
is a commissioned officer in the U.S. Public Health Service and is the Chief of the Technical Assistance Branch, Division of Occupational Health and Safety, National Institutes of Health.
JULIANNE L. BARON, PhD,
is the biological safety program manager in the Vanderbilt Environmental Health & Safety department serving both Vanderbilt University and Vanderbilt University Medical Center.
DAVID MARTINSON, PhD,
works as a biodefense contractor specializing in biosafety, biosecurity, and laboratory animal care and use.
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