Laboratory Safety-1 PDF

Chapter 2 Laboratory Safety 1 Author: Dr. Malkhaz Babuashvili Georgia, Tbilisi @2024 2-1. Facilities and Safety Overview A laboratory safety program is important in order to protect the lives of employees and patients, to protect laboratory equipment and facilities, and to protect the envir...

Chapter 2 Laboratory Safety 1 Author: Dr. Malkhaz Babuashvili Georgia, Tbilisi @2024 2-1. Facilities and Safety Overview A laboratory safety program is important in order to protect the lives of employees and patients, to protect laboratory equipment and facilities, and to protect the environment. Negligence of laboratory safety is very costly. Secondary effects of a laboratory accident are: loss of reputation loss of customers / loss of income negative effect on staff retention increased costs–litigation, insurance. Ensuring quality and safety during laboratory processes is a major concern for laboratory managers. Often, the laboratories they manage are designed by architects and/or administrators who have little knowledge of specific laboratory needs, making the job of the manager more difficult. As a Laboratory director, it is important to: actively participate in the design and planning stages of new laboratory facilities; assess all potential risks and apply basic concepts of organization in order to provide a proper and safe environment for conducting laboratory activities, including services to patients; consider the organization of the laboratory when developing new activities or new diagnostic techniques in the laboratory. 19 | P a g e As a Quality manager (or designated Safety Officer), it is necessary to: develop a complete and thorough description of basic safety rules and organization and ensure that personnel are trained in their specific duties when new activities or techniques are introduced into the laboratory; know the basics of safety and biosafety management issues when working with chemicals and pathogens of moderate or low level of risk; know how to perform an extensive risk assessment when developing new activities in the laboratory; conduct laboratory safety audits. As a Laboratorian it is important to: be aware of basic safety rules and processes; understand the basics of safety and biosafety management issues when working with toxic chemicals, biological samples, physical hazards, and when interacting with patients. Everyone in the laboratory is responsible for quality and safety. 2-2. Laboratory Design When designing a laboratory or organizing workflow, ensure that patients and patient samples do not have common pathways. Circulation paths should be designed in such a way that contact between the public and biological materials can occur only in the rooms where patient samples are collected. The reception desk where incoming patients register should be located as close as possible to the entry door. Access to rooms where manipulation or analysis of samples takes place or where hazardous chemicals or other materials are stored must be restricted to authorized persons, usually laboratory technical staff and maintenance staff. Restriction of access may be accomplished using signs on doors, locks when appropriate, and staff identification badges. To identify where improvements in laboratory design may be needed in order to prevent or reduce risks of cross-contamination, follow the path of the sample as it moves through the laboratory during the pre-examination, examination, and post-examination phases of testing. Pathways to assess include Sample collection areas—A laboratory layout with both the reception and the sample collection room located at the entrance saves time and energy. Sample processing areas—Here, samples are centrifuged, as needed, allocated for different examinations, and dispersed to the appropriate sections of the laboratory for analysis. If possible, locate the sample processing area separated from but nearby the testing areas. 20 | P a g e  Circulation pathways of biological samples between different sections of the laboratory—These pathways should be assessed for the purpose of minimizing contamination risks. If possible, circulation pathways of clean and dirty laboratory materials should never cross, and circulation pathways of contaminated waste should be isolated. Post-examination pathways—After the analysis of the samples, the results must be accurately recorded, properly filed, and delivered on time to the right person. Communication systems appropriate to the size and complexity of the laboratory including the efficient and reliable transferring of messages should be part of the laboratory design. For the most efficient design, all related services should be located in close proximity. 2-3. Geographic or Spatial Organization Spatial provision for equipment When organizing laboratory work space, divide the laboratory into areas with different access control in order to separate patients from biological samples. Where samples are actually processed, plan for spatial organization that ensures the best service. For optimal organization of the laboratory, consider: Delineation of laboratory activities—Care should be taken to either group related activities in a single room, or to clearly delineate bench space for specific activities. Measures must be taken to prevent cross-contamination of samples. Location of service rooms—Service rooms to accommodate autoclaves, sinks for cleaning glassware, preparation and sterilization of culture media, and others, should be located in a central area to minimize distances and facilitate circulation paths of materials, samples, and goods. A responsible staff member should be designated to oversee cleaning and maintenance of the service rooms. Location of activities with specific requirements, such as: 1. molecular biology—needs to be located in a separate space, with at least two rooms, so that preparation of DNA extracts is not performed in the same room as where the subsequent steps (preparation of reagent mixes and DNA amplification) are performed; 2. fluorescence microscopy—requires a dark room with proper ventilation; it must not be used for storage of stock materials and other chemicals; 3. UV illumination systems for DNA gel photography—requires a dark room and appropriate eye protection equipment. The Laboratory director and Safety Officer must consider special needs for equipment when designing laboratory space. Some things to consider are: 21 | P a g e  access to equipment for entry and maintenance—Make sure that there are no physical restrictions for access such as door and elevator size that could pose a problem for the delivery and maintenance of new machines and equipment. power supply—Consider the need for a stable power supply for sensitive equipment, and a back-up power supply or emergency generator for times when the laboratory’s primary power source is down. managing disposal of liquids from equipment—Disposal of liquid reagents, by products, and wastes from laboratory equipment and procedures is a major concern for laboratories. When placing equipment in the laboratory, be sure to consider how liquid wastes will be handled. It is important to be aware of, and comply with, local and national requirements for liquid waste disposal, in order to prevent contamination of community sewage systems with pathogens or toxic chemicals. 2-4. Physical Aspects of Premises and Rooms Facilities The laboratory must be designed to ensure proper ventilation throughout, with an active ventilation system, and adequate space for circulation of persons and laboratory carts and trolleys. Rooms should have a high ceiling to ensure proper ventilation, and walls and ceilings should be painted with washable, glossy paint or coated with a material suitable for cleaning and disinfection. The floor must also be easy to clean and disinfect, and have no edges between the walls and floor. Laboratory work benches should be constructed of materials that are durable and easy to disinfect. If the laboratory’s budget allows, ceramic tiles are good materials to use for benchtops, as they are easy to clean and are resistant to deterioration from harsh disinfectants and aggressive cleaning products. However, be aware that the grout between them can sometimes harbor contaminating microorganisms, so must be disinfected regularly. Wood should not be used, as it is not easy to clean or to disinfect, and will deteriorate over time when repeatedly exposed to disinfectants and detergents. Wood also harbors growth of contaminants when wet or damaged. The disadvantage of using steel for benchtops is that steel will rust when washed with chlorine. It is advisable to organize work benches according to the type of analysis that is performed, with adequate space for benchtops equipment and enough space to place SOP while in use and display job aids. In areas where microbiology procedures are performed, work benches should be separated by the different types of samples or pathogens that are analyzed in order to minimize risks of cross- contamination. It is very important that all areas of the laboratory be cleaned and maintained on a regular basis. Examples of areas that need daily attention are: 22 | P a g e  benchtops—Clean and disinfect benchtops after completing examinations, and after any spills of samples or reagents. This responsibility is generally assigned to the technical staff performing the tests. floors—These are usually cleaned by cleaning staff, unless restricted access allows only technical staff to disinfect the floors at the end of the day. Other areas of the laboratory should be scheduled for cleaning on a weekly or monthly basis, depending on laboratory conditions. For example, ceilings and walls may require cleaning weekly, whereas items such as refrigerators and storage areas might be scheduled for a monthly cleaning. Cleaning and disinfection of laboratory areas should be recorded, including the date and name of the person performing the maintenance. 2-5. Safety Management Program Often, the responsibility for developing a safety program and organizing appropriate safety measures for the laboratory is assigned to a laboratory safety officer. In smaller laboratories, the responsibility for laboratory safety may fall to the laboratory manager or even to the quality officer. The steps for designing a safety management program include. Developing a manual to provide written procedures for safety and biosafety in the laboratory. Organizing safety / biosafety training and exercises that teach staff to be aware of potential hazards and how to apply safety practices and techniques. Training should include information about universal precautions, infection control, chemical and radiation safety, how to use personal protective equipment (PPE), how to dispose of hazardous waste, and what to do in case of emergencies. Setting up a process to conduct risk assessments. This process should include initial risk assessments, as well as on-going laboratory safety audits to look for potential safety problems that can be corrected. The Safety Officer should be assigned responsibility for ensuring that there is an adequate supply of appropriate equipment for safety and biosafety, such as: personal protective equipment (PPE) fire extinguishers and fire blankets appropriate storage and cabinets for flammable and toxic chemicals eye washers and emergency shower waste disposal supplies/equipment first aid equipment. Policies should be put in place that outline the safety practices to be followed in the laboratory. Standard laboratory safety practices include the following: Limiting or restricting access to the laboratory. 23 | P a g e  Washing hands after handling infectious or hazardous materials and animals, after removing gloves, and before leaving laboratory. Prohibiting eating, drinking, smoking, handling contact lenses, and applying cosmetics in work areas. Prohibiting mouth pipetting. Using techniques that minimize aerosol or splash production when performing procedures. Biosafety cabinets should be used whenever there is a potential for Sheet aerosol/splash creation or when high concentrations/ large volumes of infectious agents are used. Preventing inhalation exposure by using chemical fume hoods or other containment devices for vapors, gases, aerosols, fumes, dusts, or powders. Properly storing chemicals according to recognized compatibilities. Chemicals posing special hazards or risks should be limited to the minimum quantities required to meet short-term needs and stored under appropriately safe conditions (i.e. flammables in flammable storage cabinets). Chemicals should not be stored on the floor or in chemical fume hoods. Securing compressed gas cylinders at all times. Decontaminating work surfaces daily. Decontaminating all cultures, stocks, and other regulated wastes before disposal via autoclave, chemical disinfection, incinerator, or other approved method. Implementing and maintaining an insect and rodent control program. Using PPE such as gloves, masks, goggles, face shields, and laboratory coats when working in the laboratory. Prohibiting sandals and open-toed shoes to be worn while working in the laboratory. Disposing of chemical, biological, and other wastes according to laboratory policies. Monthly and yearly exercises must be organized for fire drills and laboratory evacuation procedures. This is an occasion for the Safety Officer to emphasize risks to laboratory staff and to review with them the specific procedures for evacuation, handling of incidents, and basic security precautions. Laboratory waste management is a critical issue. All potentially harmful and dangerous materials (including liquids and radioactive materials) must be treated in a specific way before disposing. Separate waste containers should be used depending on the nature of the waste, and must be clearly identified by a color code. Specific attention should be given to the management of potentially harmful contaminated waste such as sharps, needles, or broken glassware. Sharps containers must be available on the work benches so they are conveniently accessible to staff. 24 | P a g e 2-6. Identification of Risks Laboratory workers encounter risks in significant numbers; the risks vary with the types of activities and analyses that are performed. Risk assessment is compulsory for the laboratory director in order to manage and reduce risks to laboratory employees. Assistance from a safety officer is needed to appreciate potential risks and incorporate appropriate preventive measures. It is important to develop safety procedures that describe what to do in case of accidents, injuries, or contamination. In addition, it is important to keep a record of staff exposures to hazards, actions taken when this occurs, and procedures put into place to prevent future occurrences. An outcome of a study of physical risks encountered by laboratory staff that was conducted by the Howard Hughes Medical Institute, Office of Laboratory Safety is shown in the chart. This study only addressed physical risks, but personnel contamination and infection have been reported in many instances, and recent reports on laboratory acquired infection by SARS show that the risks are never reduced to zero, even in high confinement facilities. Laboratory equipment is a significant source of potential injury to laboratory staff, thus making training on specific safety procedures imperative. Examples of equipment in which safety training and precautions are important include autoclaves, centrifuges, compressed gas cylinders, and fume hoods. Many laboratory instruments pose a danger of electrical shock, and some equipment can emit dangerous microwaves or radiation, if not properly used or maintained. Storage of compressed gases in the laboratory requires precautions unique to the unusual containers in which these materials are kept, and the high pressures to which they are subject. Cylinders are kept chained to the wall so that they cannot fall over. The safety caps must be secured over the valve of the cylinder whenever a gas bottle is moved or taken out of service. Needles, broken glass, and other sharps need to be handled and disposed of appropriately to prevent risks of infection to laboratory and housekeeping (custodial) staff. For proper disposal of sharps, the following instructions should be followed: Needle recapping is not advisable or necessary. If recapping is crucial, the correct procedure is for the person doing the recapping to keep one hand behind the back, and using the other hand to scoop the cover onto the needle. 25 | P a g e  Put sharps in a puncture-resistant, leak-proof, sharps container. Label the container with the word, "SHARPS”. If the sharps are not biohazardous, deface any BIOHAZARD markings or symbols, and then seal the container tightly. Laboratory glass and plastic ware are not considered to be sharps for disposal purposes. Laboratory glass (including plastic ware) is any item that could puncture regular waste bags and therefore endanger waste handlers. Laboratory glass must be placed in sturdy cardboard boxes for safety during transport through the building. Any cardboard box may be used, provided it is sturdy and of a size that will not weigh more than 40 pounds when full. Contaminated laboratory glass must be appropriately decontaminated prior to disposal. Never use boxes for the disposal of: sharps; biohazardous materials that have not been autoclaved; liquid wastes; chemically contaminated laboratory glassware / plastic ware; chemical containers that cannot be disposed of as regular solid waste. Exposure to toxic chemicals poses a real threat to the health and safety of laboratory staff. There are three main routes in which chemicals enter the body. Inhalation—This is the major route of entry when working with solvents; there is great rapidity of absorption when fumes are inhaled. Absorption through skin—This may produce systemic poisoning; the condition of the skin determines the rate of absorption. Examples of chemicals with these risks are organic lead, solvents such as xylene and methylene chloride, organophosphate, pesticides, and cyanides. Ingestion—Accidental ingestion is generally due to poor hygiene practices, such as eating or smoking in the laboratory. To prevent or reduce incidents caused by exposure to toxic chemicals, all chemicals, including solutions and chemicals transferred from their original containers, should be labeled with their common names, concentrations, and hazards. Additional information such as the date received, date opened, and date of expiration should also be recorded. It is crucial that chemicals be stored properly. Store corrosive, toxic, and highly reactive chemicals in a well- ventilated area, and store chemicals that can ignite at room temperature in a flammables cabinet. Radiochemicals require special precautions, and need dedicated benches with specific bench covers for manipulation of radiolabelled elements. Specific storage areas for radioactive materials are needed. These must provide appropriate protection (plexiglass, lead) and specific waste containers, depending on the chemical nature of waste and radio elements. 26 | P a g e  The Material Safety Data Sheet (MSDS) is a technical bulletin providing detailed hazard and precautionary information. 1 Businesses are required to provide to their customers the MSDS for all chemicals they manufacture or distribute. Laboratories need to heed precautions listed in the MSDS in order to ensure the chemicals they use are handled and stored safely. The MSDS provides the following information: product information fire and explosion precautions toxicology health effects personal protective equipment (PPE) that is recommended storage recommendations leaks and spills—recommended actions waste disposal recommendations first aid. Material Safety Data Sheets should be: available to all employees prior to use of hazardous materials; kept close to where the hazardous material is used and located. Laboratory-acquired infections are not infrequent in medical laboratories. Aerosols are the main sources of contamination within diagnostic laboratories; contamination can occur over very long distances. This is why the major target of containment systems is the blockage of aerosol diffusion in and outside the laboratory. Diagnostic laboratories of containment level 2, where activities concern only pathogens of moderate risks, must have appropriate ventilation. Higher containment level laboratories or working cabinets must ensure a continuous inward air flow as well as an absolute filtration of exhausted air, to avoid aerosol dissemination outside the working area and/or the whole laboratory. 2-7. Personal Protective Equipment (PPE) The major routes in which laboratory staff acquire work-related infections are: inhalation of aerosols generated by accident or by work practices; percutaneous inoculation; contact between mucous membranes and contaminated material; accidental ingestion. To reduce the risk of these occurrences, it is imperative that staff have access to personal protective equipment (PPE), be trained in how to properly use it, and habitually use the PPE while working in the 27 | P a g e laboratory. Approved goggles, face shields, splatter guards, masks, or other eye and face protection should be worn when handling infectious or other hazardous materials outside the biosafety cabinet. Gloves should be worn in all instances, and be available to laboratory staff on a routine basis. Effective use of gloves, however, relies on two simple practices. 1. Remove gloves when leaving the working area to prevent contamination of other areas such as the telephone, door handles, and pens. 2. Never re-use gloves. Do not attempt to wash or decontaminate gloves — they will develop micro cracks, become more porous, and lose their protective properties. After use, gloves must be disposed of in the contaminated waste. Goggles—The projection of droplets is a frequent occurrence when opening patient sample containers. Protection of eyes and other mucous membranes is strongly recommended to prevent contact with these droplets; the use of goggles will protect eyes and should be systematic for this step. Another way to protect eyes and other mucous membranes from projection is to manipulate the specimen tubes behind a screen, glass or plexiglass, or face shield. This equipment should be compulsory as well, when manipulating dangerous liquids, such as liquid nitrogen or some solvents. Contact lenses do not offer protection from splashes. Additional eye protection must be worn with contact lenses. Masks—Masks serve as a barrier when splashes or sprays occur. Laboratory coats are compulsory in all instances in the regular level 2 laboratory. Be aware of the composition of fabrics, as some might be highly flammable. A disposable laboratory coat is compulsory in level 3 laboratories or in specific instances such as sample collection when highly dangerous pathogens can be involved, such as suspected cases of H5N1 avian influenza or severe acute respiratory syndrome (SARS). 2-8. Describe how different types of PPE can provide protection. PPE, or personal protective equipment, refers to equipment or safety clothing designed to protect the wearer/user from injury or infection and will be worn to minimize exposure to various occupational hazards and risks. Injuries and illnesses may result from contact with chemical, radiological, physical, electrical, mechanical, or other workplace hazards, such as potentially infectious (biohazardous) material. The need for PPE will be dependent upon:  The hazard(s) and risk(s) that may be present  The type of work operations  The nature and quantity of the hazardous materials in use PPE selection and use must be assessed based on the hazards and risks that may be present. Those who rely on PPE must understand its proper use, functioning, and limitations of the PPE being used. 28 | P a g e The Centers for Disease Control and Prevention (CDC) and the National Institute for Occupational Safety and Health (NIOSH) recommend a hierarchy of safety controls: The CDCs Hierarchy of Control These recommendations guide the primary safety methods for protecting employees in a laboratory against chemical, biological, radiological, physical, and mechanical hazards. The primary method described in the NIOSH Safety Hierarchy to provide a safe work environment is to eliminate the hazard(s) and risk(s) as best possible, followed by a substitution method to reduce the hazard(s) or risk(s). After elimination and substitution method considerations, engineering and administrative controls should be utilized to further reduce hazards and risks. When these control methods are not appropriate or sufficient to control the hazard(s), PPE will typically be required as mitigation and may be used in combination with the other methods. There is a large variety of PPE used in occupational settings to mitigate the various hazards and risks. PPE in many industries may include items such as gloves, safety glasses, shoes, earplugs or muffs, hard hats, respirators, coveralls, vests, full body suits, etc. This training will focus on PPE commonly used in clinical lab settings and will be outlined as:  Body protection o Lab coats, gowns, and aprons  Eye and face protection o Safety glasses, goggles, face shields  Hand protection o Latex, nitrile, insulated, and chemically resistant gloves  Respiratory protection o Face masks and respirators  Other considerations o Foot protection o Sleeve guards o Personnel clothing and dress codes Laboratory coats provide a layer of protection for skin and personal clothing from incidental contact and minor splashes and are often used in combination with other appropriate PPE and engineering controls. Laboratory coats also: 29 | P a g e   Act as a removable barrier in the event of an incident involving a spill or splash of hazardous substances.  Prevent the spread of contamination outside the lab (provided they are not worn outside the lab).  Typically, will be ‘button up’ or ‘snap up' the front.  Can be disposed of after use if made of disposable material or should be washed/laundered by an approved method or vendor on a regular basis (NOT at home) and according to lab policy. Lab coats should:  Cover the entire upper body  Extend to the knees  Fit comfortably without hanging too loosely from the arms  Have a fitted wristband/cuff to reduce the potential for splashes up the arm  Be made fire-retardant material when flames or other fire hazards are present o 35% polyester and 65% cotton blends are commonly used o Cotton also has semi-fire-retardant properties, whereas polyester possesses additional resistance to chemicals Gowns will typically be a ‘solid impermeable front’ with a tie/string closure around the back and/or neck, or on the side/front, and have elasticized cuffs. Gowns also:  Offer a broad barrier and increased protection from splashes and are commonly used in higher-risk work settings (e.g., when there is a higher risk of splashes).  Can be worn on top of clothing or on top of a lab coat.  Can be made of disposable or reusable material and sometimes called ‘isolation gowns’. When choosing a gown, look for product labeling that describes intended use with the desired level of protection based on the determined risk levels. Chemical-resistant aprons may be needed based on the identified hazard(s) and potential risk(s) from an assessment. They are commonly used as protection when there may be an additional splash hazard or with procedures such as:  Removing liquid nitrogen  Handling or pouring large volumes of liquid samples or corrosive chemicals  Performing autopsies or necropsies  Manipulating chemicals in a manner that increases the likelihood of splashes or spills Aprons are commonly made of plastic, vinyl, PVC, or neoprene, and rubber aprons are typically best for protection against corrosive or irritating liquids. They are designed to be worn on their own or with a lab coat to provide extra protection. Aprons should fit comfortably and extend from just below the neck to just above the tops of the feet. Safety glasses will typically be required PPE whenever working with hazardous material, especially when there may be a potential splash hazard. 30 | P a g e Safety glasses provide eye protection against minor spills and splashes, as well as some flying objects. They typically do not provide adequate protection from significant chemical splashes since they do not seal to the face, resulting in gaps at the top, bottom, and sides, where chemicals may seep through. Additional information about safety glasses includes:  Regular (prescription) glasses are not safety glasses.  Safety glasses will be worn over prescription glasses.  Prescription safety glasses may be acceptable if they have side shields for splash protection.  Safety glasses should meet the American National Standards Institute (ANSI) Z87.1 - 2010 standard for impact and shatter resistance and have side shields for splash protection.  Typically, the frame or lenses will be marked with “Z87”.  Safety glasses should be regularly cleaned with an appropriate cleaner and/or disinfectant and should be replaced when they become too scratched, marked, or damaged to use safely. Safety goggles should form a protective seal around the eyes and prevent objects or liquids from entering under or around the goggles. They offer side and forward-facing protection and come in various styles for maximum user comfort and splash protection. Some types may be worn over prescription glasses. Goggles may be required for specific processes where safety glasses are deemed inadequate and when work may involve hazardous liquids that may splash, spray, or mist. ace shields should be worn in addition to safety glasses or goggles whenever a splash hazard is present when working with large volumes of hazardous materials. They are often used in combination with other PPE, such as a mask or respirator. Face shields provide eye and face protection (mucus membrane) and are secondary protectors intended to protect the entire face against exposure to splashes. Hand protection should be worn when there are potential hazards for skin absorption of harmful substances, chemical or thermal burns, electrical dangers, punctures/lacerations, or to reduce exposure to contamination from handling potentially infectious substances. While wearing gloves, be careful to only touch materials associated with the task at hand and take caution not to contaminate yourself or your surroundings. Touching objects such as lab equipment, phones, waste containers, or other surfaces may result in contamination. Be mindful not to touch your face, hair, clothing, etc. Gloves should not be worn outside of the laboratory. Disposable gloves should not be reused or disinfected before disposal due to potential exposure in the disinfection process. Disinfectants may also degrade the glove material integrity. Disposable gloves should be changed when there is any sign of contamination. Reusable gloves should be washed routinely and air-dried before reusing them. 31 | P a g e No single glove material provides complete protection against all chemicals and other hazards. Gloves will need to be resistant to the chemicals and other potential hazards being used and handled while not putting the wearer at risk due to loss of dexterity if they are too thick or not the appropriate size. Some Safety Data Sheets (SDSs) provide glove selection information in the ‘Handling Section’ for some hazardous materials. Glove manufacturers will also provide intended use information that labs should consult before selecting gloves to use as PPE. There are various types of gloves used in the lab to provide protection against several types of hazards. The selection of gloves will depend upon the purpose and nature of the work and hazards that may be present. This training will only focus on the following types of gloves:  Latex  Nitrile  Insulated  Chemical resistant Typically, gloves will not be sterile unless specifically identified by the manufacturer. Latex gloves provide hand protection from the risk of exposure to biological hazards and potentially infectious material. They do not provide adequate protection against many chemical hazards. Since latex can cause allergic reactions and sensitivities in some individuals, many institutions have completely substituted latex gloves with nitrile. Latex gloves should not be reused. Nitrile gloves are very commonly used in clinical lab settings due to the range of hand protection and all-purpose use they provide. They offer protection against infectious material and many routine hazardous chemicals found in the lab, such as solvents, oils, petroleum products, and some corrosives. Nitrile gloves are typically more puncture resistant than rubber gloves. They should not be reused. Insulated gloves can provide protection against excessive heat or cold. Heat-resistant gloves will typically be used for unloading an autoclave or other heat or steam cleaning machines, as well as handling samples or other material that may be of a higher temperature (e.g., specimens on a heat block or in a water bath). Cryogenic gloves will typically be used when handling liquid nitrogen, dry ice, or specimens frozen at ultra-low temperatures (e.g., -70°C). They may be water-resistant or waterproof, however, no cryo- protective glove is intended to provide protection against direct immersion in cryogenic liquids. Certain chemicals pose a skin absorption risk and will require additional attention for glove selection based on a laboratory risk assessment. Gloves will have protection limitations based on exposure time and chemical concentration. 32 | P a g e Chemical-resistant gloves should be selected based on the specific chemical(s) to be used and the manufacturer’s glove permeation and compatibility charts. The chemical SDS should also be consulted to verify chemical compatibility with the gloves being used. Neoprene gloves are made from synthetic rubber and are typically very liquid-proof and chemical- resistant, although not always very flexible.  Used for specialized chemical applications involving acids, caustics, oils, alcohols, and solvents.  Provides moderate abrasion resistance but good tensile strength and heat resistance. Butyl gloves are made from rubber and are usually very flexible. They are to be used for handling some types of strong corrosives, acids, or solvents. Butyl gloves offer strong resistance to permeation by most gases and water vapor. Respiratory PPE should be considered when respiratory hazards may exist (e.g., infectious aerosols or droplets) and there are limited or no containment options or other engineering controls, such as the availability and use of a biological safety cabinet (BSC). A respirator is a protective device designed to protect the wearer from exposure to hazardous atmospheres, including airborne particles such as dust, bacteria, virus, etc. It will fit tightly to the face. There are several types, models, and manufacturers of tight-fitting respirators. In a clinical lab setting, the typical types of respirators used are N95, KN95, P100, or PAPRs (powered air purifying respirators), with N95s being the most commonly used type. The decision on whether to use a disposable face mask or a respirator (e.g., N95) will depend on the laboratory site-specific and activity-specific risk assessment and the hazards that may be present. If your lab requires a respirator (e.g., N95) to be used for work, you will need to pass a medical evaluation first according to OSHA (the Occupational Safety and Health Administration), and the user must be fit- tested on an annual basis with the type of respirator that will be worn. A required respiratory protection program will include: 1. Respiratory hazard evaluation 2. Medical evaluation and clearance 3. Fit testing 4. Respiratory protection plan and policies 5. Training Respirators are characterized based on the different levels of resistance to oily aerosols and filter efficiency. Below are the various respirator classes:  N = not resistant to oil  R = resistant (somewhat) to oil  P = oil proof (strongly resistant to oil) 33 | P a g e Efficiency ratings are based on the number of particles that can be stopped by using the respirator. Below are the various efficiency ratings:  95% efficient at stopping particles 0.3 μm (microns) in diameter  97% efficient at stopping particles 0.3 μm  99.97% efficient (referred to as 100%) at stopping particles 0.3 μm in diameter N95 and P100 respirators should meet NIOSH certification standards, whereas KN95s are respirators manufactured and approved in China according to their standards. CDC, NIOSH and the FDA (Food and Drug Administration) provide websites with information about approved masks and respirator devices according to the product manufacturer Facemasks are loose-fitting, disposable masks that cover the nose and mouth, such as surgical and dust masks. They are typically resistant to fluids and can protect from large droplets, splashes, or sprays of body fluids. NIOSH does not approve facemasks for protection against any regulated hazardous material. Therefore, they are not considered respiratory protection because gases, vapors, and tiny particles (e.g., bacteria and viruses) can pass through them. Some surgical grade masks are cleared for use as medical devices by the FDA and are designed to be worn by healthcare professionals and provide a level of fluid resistance. Facemasks are commonly used to help stop potentially infectious droplets and other respiratory emissions from being spread by the person wearing them. Powered Air Purifying Respirators (PAPR) PAPRs, or powered air purifying respirators, are ‘positive pressure’ respirators that supply purified air to the headpiece and push HEPA (high-efficiency particulate absorbing) filtered air away from the face because they do not have a tight seal to the face. A medical evaluation is not required prior to use since it is not a tight-fitting respirator. There are several models, types, and manufacturers available, but almost all will have a removable hood/headpiece (with or without a shroud that can cover the neck area), a connector hose, battery pack, and HEPA filter that usually straps around the waist. PAPRs are reusable and should routinely be cleaned and disinfected between uses and users. Laboratory footwear should be closed-toed and fully cover the feet to protect against chemical spills and other contamination hazards. Avoid shoes like sandals, flip flops, canvas or other permeable material or fabric tops. Dedicated footwear for lab work may be recommended depending on risk assessment. Disposable shoe covers may be used to provide added protection at times such as in high containment laboratory spaces [e.g., Biosafety Level 3 (BSL-3) work], patient isolation rooms, or other areas to help prevent the removal of any contamination from out of the higher risk setting. Disposable sleeve guards can provide additional protection to the wrist and arm areas. 34 | P a g e   Sleeve guards are typically used when:  Lab coat sleeve length not long enough, and cuffs may not overlap the gloves fully  Working in molecular testing labs to prevent lab personnel from contaminating their work with their own shedding skin. Based on a risk assessment, laboratories will have their own dress codes, policies and recommendations that will typically include items such as:  Long hair being tied back and out of the way.  Wearing long pants that cover to the ankle, and pants that are not frayed or torn.  Wearing clothing made of natural fibers since they are fire resistant.  Wearing clothing to cover skin as best possible. 2-9. Determine how to select appropriate PPE for clinical laboratory work. If PPE is to be used in the workplace, a PPE program should be implemented and include:  Identification and mitigation of the hazard(s) and risk(s) present  Selection, maintenance, and use of PPE  PPE training for employees  Monitoring of the program to ensure its ongoing effectiveness and if any PPE changes are needed  Providing PPE for free to staff Following are some major considerations when selecting the appropriate types of PPE:  Meets national and any state-specific safety requirements and recommendations.  May be used in different combinations between labs or between work.  Provide a size variety selection for staff to choose from.  Helps delay or limit the transfer of hazardous materials to personal clothes or skin.  Protects personal clothes and skin from possible contamination. 35 | P a g e   Adequately provides the user protection in the workplace from identified hazards. It should also be evaluated if the PPE will act as a primary barrier between user and hazard(s) such as infectious substances, chemicals, or other hazardous materials, or if it will be used in combination with other controls. A laboratory process/task risk assessment should be conducted to identify the potential hazards, determine associated risks, and to select the appropriate PPE for protection as a mitigation in combination with other controls. Labs should consider aspects such as the types of specimens that will be handled, the facility capabilities, the staff qualifications, as well as other safety equipment and methods that can be used, etc. The lab’s Safety Plan should be enforced and should define and document tasks and activities, associated hazards, and any PPE required for protection and mitigation. Employers are required to provide the following training to each worker required to use PPE:  When PPE is necessary  What kind of PPE will be necessary?  How to properly don (put on), adjust, wear, and doff (take off) PPE  The limitations of the PPE  Proper care, maintenance, use, and disposal of PPE Laboratory management should ensure that staff demonstrate the ability and competence to properly wear and use PPE before they can perform work using PPE. Retraining may be necessary if work conditions change or staff fails to demonstrate the proper use of the assigned PPE. Employers should conduct a hazard assessment to identify the appropriate PPE mitigations based on a laboratory risk assessment. Additionally, employers need to make PPE available to employees at no cost, train employees in the use and care of PPE, and create a PPE maintenance program (e.g., replacing worn or damaged PPE, routinely reassessing if PPE adequately matches hazards, etc.). It is each employee's responsibility to properly wear, use and dispose of PPE. Employees must also attend related and required PPE training sessions and notify the lab manager, supervisor, or safety officer of the need for new or additional PPE. Appropriate PPE will be required when there is a potential for exposure to hazardous materials such as hazardous chemicals and infectious (biohazardous) substances. Proper PPE and laboratory attire help minimize the potential for skin exposure to hazardous chemicals, biological agents, and other hazardous materials. Laboratories must develop and implement their own lab-specific PPE policies and practices to ensure a safe workplace based on lab-specific risk assessments. Most clinical laboratories operate at a biological safety level 2 (BSL-2) setting for routine clinical lab work. Following the CDC recommended standard precautions for healthcare settings/patient care and 36 | P a g e the BSL-2 laboratory safety practices described in the Biosafety in Microbiological and Biomedical Laboratories (BMBL) will be appropriate for most routine clinical lab work and associated sample handling hazards. Laboratory PPE that is typically worn in BSL-2 settings includes:  Lab coat and/or gown (at times)  Gloves (nitrile)  Safety glasses and/or face shields (at times)  Respiratory protection (at times) Based on a risk assessment, there may be times when additional PPE may be needed as an extra precaution based on the work or the setting. 37 | P a g e