Gloves

Selection of glove type and material is based on the type of exposure and nature of the hazard. Some chemicals can easily penetrate gloves that work very well for other chemicals. The following should be considered when choosing gloves necessary for work in the animal facility:

• Chemical type
• Temperature extremes and cryogenic properties
• Physical hazards (sharps and piercing objects)
• pH
• Toxicity
• Infectious potential
• The procedure to be conducted

Additionally, one should consider whether the gloves are for incidental or extended contact with a hazardous agent. Incidental contact may involve little or no direct exposure to the hazardous material, and uses may include activities such as accidental spills or splashes, overspray from a dispensing device, handling of infectious agents that require barrier protection, and preventing contamination of materials (product protection), or during sterile or aseptic procedures. Disposable, surgical-type gloves are appropriate for incidental contact, as are nitrile gloves. Often, nitrile gloves are preferable to latex gloves because of better chemical resistance and the tendency to visibly tear when punctured, and in situations where the worker has a latex allergy or to protect against development of a latex allergy. When the choice is made to use disposable gloves, check for tears or punctures before use, remove and replace gloves immediately if overtly contaminated, and avoid touching common objects (door knobs, keyboards, etc.) while wearing gloves. Never wash or reuse disposable gloves.

Extended glove contact to hazardous materials may include situations such as handling highly contaminated materials, submerging hands in or prolonged contact with a chemical or other hazardous substance, and the need for physical protection from temperature extremes or sharp objects. More substantial gloves are generally required for extended use, and many of these gloves are reusable. Reusable gloves must be inspected for tears or punctures before and after each use and for evidence of prior contamination and/or degradation. Extended-use, reusable gloves should be washed and air-dried after removal. Table 14.1 will aid the reader in proper glove selection.

Table 14.1

Proper Glove Selection in the Animal Facility.

Mucous Membrane Protection

Mucous membrane protection refers to protection of the eyes, nose, and mouth from splash and splatter of potentially contaminated materials. This nomenclature originally referred to protective devices used to prevent occupational transmission of human immunodeficiency virus (HIV) in the health care workplace via mucous membrane exposure of the workers. The use of the term has evolved and is now more broadly applicable. This type of personal protection includes goggles, face masks, and face shields, and specific devices should be chosen after careful risk assessment of the task at hand. Ideally, appropriate mucus membrane protection should be selected with the guidance of a trained occupation safety specialist. Figure 14.4 provides additional guidance on the selection of face masks.

Figure 14.4

(See color insert.) Guidelines for the selection and use of face masks. (From CROSSTEX, Hauppauge, NY, http://www.crosstex.com/home.asp.)

Respiratory Protection

Respirators are devices fitted to the individual that can protect workers against insufficient oxygen environments, harmful dusts and other particulates, fogs, smokes, mists, gases, vapors, and sprays (http://www.cdc.gov/niosh/docs/2005-100/pdfs/2005-100.pdf). Respirators protect the user in two basic ways. The first is by the removal of contaminants from the air. Respirators of this type include particulate respirators, which filter out airborne particles, and powered air-purifying respirators (PAPRs) with cartridges or canisters that filter out chemicals and gases. Other respirators protect by supplying clean breathable air from another source. Respirators that fall into this category use compressed breathing air from a remote source (such as those used in maximum containment facilities”“ABSL-4) and self-contained breathing apparatus (SCBA), which is a dedicated air supply (tank air). Workers should use respirators for protection from contaminants in the air only if other hazard control methods are not practical or possible under the circumstances. Respirators should not be the first choice for respiratory protection in workplaces. They should only be used

• When following the “hierarchy of controls” is not possible (elimination, substitution, engineering, or administrative controls)
• While engineering controls are being installed or repaired
• When emergencies or other temporary situations arise (e.g., maintenance operations)

Workers wearing respirators to accomplish work tasks must be enrolled in an appropriately constituted respiratory protection program as defined by national or regional authorities, consult an industrial hygienist or other safety and health professional in selection and fit testing of the appropriate respiratory protective device, and be medically cleared to use a respirator.

Hearing Protection

Animal facilities have high-noise areas, such as mechanical spaces, cage wash areas, and housing areas where animals may loudly vocalize. Exposure to high levels of noise can cause permanent hearing loss (https://www.osha.gov/SLTC/noisehearingconservation/). Neither a hearing aid nor surgery can correct this type of hearing loss. Short-term exposure to loud noise can also cause a temporary change in hearing (ears may feel “stuffed up” or clogged) or a ringing may be present (tinnitus). These short-term problems may go away within a few minutes or hours after leaving the noisy area. However, repeated exposures to loud noise can lead to permanent tinnitus and/or hearing loss.

Loud noise can also create physical and psychological stress, reduce productivity, interfere with communication and concentration, and contribute to workplace accidents and injuries by making it difficult to hear warning signals or instructions. Animal facilities with noisy areas should establish a hearing conservation program (HCP) to identify and monitor areas where high noise levels exist and to subsequently identify employees whose job duties may expose them to noise levels exceeding the 8-hour time-weighted average. The U.S. OSHA (29 CFR 1910.95) sets the 8-hour time-weighted average action limit (or threshold limit value [TLV]) at or above 90 dBA (decibels measured on the A scale, slow response). Other authorities, such as the American Conference of Governmental Industrial Hygienists (ACGIH) and the EU Directive 2003/10/EC on workplace noise, set more conservative 8-hour exposure limits at 85 and 80 dB(A), respectively.

An HCP should address (1) high-noise-area identification and monitoring, (2) employee monitoring (personal noise dosimetry), (3) audiometric monitoring, (4) noise control (engineering and administrative controls), (5) hearing protection devices (HPDs), (6) training, (7) medical monitoring, and (8) record-keeping requirements. Personnel working in high-noise areas of the animal facility should have appropriate hearing protective devices available to them. An HPD is a personal safety product that is worn to reduce the harmful auditory and/or annoying effects of noise. HPDs should be viewed as a last resort, when other means, such as engineering and administrative controls, are not practical or economical. All HPDs have an associated noise reduction rating (NRR). Aural inserts (earplugs) fit directly into the ear canal. Earplugs in both formable and premolded versions are available in various sizes. Circumaural protectors (ear muffs), which are plastic domes that cover the ears and are connected with a spring band that fits on top of the head or is attached to a hard hat, are also an option. The HPD chosen must have an NRR that reduces the worker’s noise exposure to the established level.

Surface Hazards

The need for moisture-impermeable, highly sanitizable surfaces in the animal facility, especially for flooring, often creates slick and slippery working conditions. These situations can at times be reduced or eliminated by selecting textured materials, for example, the addition of sand or other textured additives to epoxy flooring. In addition, careful attention to moisture on the floor, the selection of facility shoes with slip-resistant soles, and/or the use of slip-resistant shoe covers helps reduce the problem.

Ergonomic Hazards

Attention to good ergonomic design can reduce or eliminate the occurrence of musculoskeletal disorders and repetitive motion injuries while improving health, safety, and productivity. It takes forethought to design and arrange a work environment that is user-friendly, efficient, and safe. Consideration must be given to the mental, physical, and organizational aspects of the work, as well as the setting in which the work is conducted. The goal is to reduce, minimize, or eliminate factors that can result in injury, pain, or discomfort.

Although potential ergonomic hazards can be identified in many of the jobs related to animal care and use, these injuries are most common in production areas where the tasks require repetitive movements or the movement of heavy objects. The purposeful placement of handholds in natural positions, coupled with attention to body position and back support, can help to eliminate many hand, wrist, shoulder, and back injuries. One example is the use of back supports coupled with the use of heavy-duty, removable quick-release suction cup handles (e.g., Harbor Freight Tools). Their use has significantly reduced ergonomic injuries related to the movement of large, heavy primate cage racks (NIH Program Data). Care must be used when recommending the use of back supports, as they may provide a false sense of security to the user. It is for this reason that some programs have stopped recommending their use. When used with appropriate training, back supports serve as a reminder to use good body posture, mechanics, and lifting procedures.

When space permits, powered equipment, such as “tugs” and forklifts, has been used to move heavy and bulky caging. The selection of smaller, lighter animal racks can also reduce ergonomic issues, but this is not always possible when trying to maximize housing densities and reduce housing costs. Another area where we have been able to improve ergonomics is the selection of uniquely designed biosafety cabinets and change hoods. Many vendors now manufacture adjustable-height cabinets and hoods that allow the employee to adjust the height of the unit to meet his or her specific requirements. Other examples of ergonomic improvements that have benefitted our employees are (1) the use of antifatigue mats and runners in areas where personnel are required to stand for prolonged periods of time; (2) the procurement of smaller, lighter bags of food and bedding; (3) the use of self-opening doors; (4) the use of lighter fiberglass cage pans versus heavier metal units; and (5) the use of ramps or other floor-leveling strategies to smooth the transition from one work area to another.

Machinery and Equipment Hazards

Any piece of machinery or equipment that has moving parts can pose a significant hazard to the operator. It is critical that the equipment is well designed and in good working order, and that precautions are taken to protect the operator from potential pinch, crush, and entrapment areas (e.g., rack washers and bulk autoclaves). Engineering controls such as strategic placement of finger guards or other barriers to minimize accidental exposure of fingers and hands are often beneficial in preventing these types of injuries. For example, retrofitting a metal guard plate at the interface of the tunnel washer conveyor belt and the cage loading area has provided additional protection for the equipment operators.

When purchasing any piece of machinery or equipment, the product should be evaluated not only for functionality, but also for safety and ergonomic design. Care should be taken to evaluate the safety of the equipment not only during routine operation, but also during equipment cleaning and maintenance. Consideration should be given to the presence and location of emergency shutoffs, signage related to potential dangers, and safety features.

It is important to evaluate not only the machinery or equipment for safety, but also the required standard operating procedures and training practices for the safe operation of the equipment. Engineering safety controls or procedural safety measures are preferred; however, they are not always possible. Therefore, well-thought-out standard operating procedures, coupled with a well-designed and -documented training program, are often required.

Heat, Steam, Cryogens, and Pressure Hazards

Heat, steam, and pressure hazards are of primary concern in the facility cage wash area, as well as other areas using heat or steam to sanitize and sterilize equipment and instruments. The use of cryogens (e.g., liquid nitrogen and dry ice) are also common in the modern laboratory animal facility. Cryogen boil-off can lead to asphyxiation of both personnel and animals. Rooms housing magnetic resonance (MR) scanners in which cryogen gases are stored must be equipped with oxygen sensors and a method for increasing room ventilation to exhaust inert gases during cryogen filling (Klaunberg and Davis 2008).

The appropriate selection and use of PPE (e.g., aprons, gloves, safety glasses, and goggles) is normally sufficient to protect personnel when they are coupled with appropriate standard operating procedures and training. It is important to ensure that gloves are both moisture and heat resistant when working in wet cage wash areas or with surfaces that may be hot, as well as moist. In addition, appropriate ventilation must be present to prevent steam and fog buildup from creating fogged glasses, goggles, and an unsafe work environment. Steam release safety interlocks must be present and in good working order in equipment where increased internal pressures are present and steam is allowed to build up (e.g., steam autoclaves). Larger pieces of walk-in equipment, for example, rack washers and autoclaves, should ideally be equipped with internal emergency shutdown or de-energizing and egress mechanisms to prevent personnel from becoming trapped inside. When working with cryogens, care must be taken to ensure that the work area is well ventilated and that the gloves selected are appropriate for the temperature ranges of the agents. When working with liquid nitrogen, eye protection should also be worn.

Lighting, Electrical, and Electromagnetic Hazards

Lighting can be a source of hazard secondary to the type of lighting fixture and amount of light provided. Fixtures that are not properly installed, in good repair, grounded, and water resistant can pose a shock hazard, especially in a wet environment. Ceiling fixtures in the animal facility are often covered and sealed with a gasket to prevent moisture penetration and bulbs from being accidently broken during room sanitation. Ideally, lighting fixtures should be easily accessible for bulb changing without having to clear the room.

Some animals are purposefully reared in dark, low-light-intensity conditions, or under red lighting. These lighting conditions can present potential safety hazards for individuals working and navigating in the area. Standard operating procedures for individuals working in low-light areas often require an acclimation period to prevent personnel injury or task performance errors. Rearing animals in the dark also requires the use of night vision goggles, which must be of sufficient quality and fit to allow routine tasks to be conducted adequately, including animal health checks. It is also important to remember that more than one pair of goggles will be required to ensure continuity of care in case one pair becomes damaged.

Electrical outlets and switches throughout high-water-use areas, such as cage washing areas and high moisture holding rooms (e.g., aquatics, flushed runs, and rooms that are hosed down), should be ground fault interrupted (GFI) and have moisture-resistant covers. In addition, grounded (three-prong) plugs should be standard for all equipment throughout the program.

The use of lasers and ultraviolet (UV) light is becoming more common in the laboratory and animal facility. Both areas require controlled access to the area when the laser or UV light is in use, and appropriate signage to warn personnel entering of the potential danger. Depending on the power and nature of the laser or intensity and wavelength of the UV light, appropriate eye and skin protection is required.

With the development of magnetic resonance imaging (MRI), electromagnetic hazards have become prevalent in animal care and use programs. It must be understood that the MRI magnet is always on. Because of the strong magnetic field created by the equipment, any ferromagnetic object brought into the scanner room or critical zone of the equipment will become magnetized and can become a dangerous projectile that could injure personnel and damage equipment. These high magnetic fields can also cause a life-threatening situation in individuals with implanted pacemakers, stents, and aneurysm clip implants. Body piercing jewelry can move when brought within the magnetic field and, in some cases, generate heat and cause burns. This is also true for some transdermal patches, tattoos, and foreign bodies, which may contain metallic components. Individuals who may be pregnant should consult with their health physicist or safety officer before working in close proximity to potential magnetic field hazards. Here again, appropriate signage and training is critical to the management of these electromagnetic hazards.

Chemical Hazards

Potential chemical hazards are numerous, but manageable, in the modern research laboratory and animal facility. It is important to always check with your safety specialist on the appropriate use and storage of potentially hazardous chemicals. Depending on the chemical hazard, chemical showers and/or eye wash stations may be required in the area. In addition to the product labeling, the material safety data sheets (MSDSs), or what are now commonly called safety data sheets (SDSs), are a good source of information and should be readily accessible to staff within the area using the material.

Acids, bases, and caustic and corrosive chemicals should be stored on shelving or in cabinets that are low to the floor. Ideally, these items should also be placed in a secondary container, such as a spill tray. The secondary containment should be big enough to contain the spill of the largest container being stored. Ideally, acids and bases should be stored away from each other, in separate secondary containment areas. Since vapors may escape a container, the cabinet or area where chemicals are stored should be ventilated or located near a ventilation system, such as a fume hood. Never store corrosive chemicals under a sink where the vapors may cause corrosion of plumbing fixtures. Ideally, shelves used to store any chemical should be designed with “endcaps” to prevent containers from accidently being pushed off the end.

In all cases, appropriate signage should be present where chemical hazards are present. Care should be taken to ensure that standard operating procedures outline the appropriate use and storage of the chemicals, required PPE, and disposal requirements.

Fire Hazards

Many types of fire hazards and flammable materials are present in the animal laboratory and facility. The National Fire Protection Association (NFPA) categorizes potential fire hazards by class, where each class indicates the nature of the flammable or combustible material. Class A hazards are ordinary combustibles, Class B flammable liquids, and so forth. Most combustibles within an animal facility fall into Classes A and B. The NFPA further classifies the area in which fire hazards are stored into three classifications: light (low) hazard, ordinary (moderate) hazard, or extra (high) hazard. Light (low) hazard areas include offices, classrooms, and meeting areas. Ordinary (moderate) hazard areas are areas where the quantity and combustibility of material is moderate, such as light manufacturing areas, research operations, parking garages, workshops, or maintenance and service areas. Extra (high) hazard areas are areas that store or use high volumes of flammable material.

The proper storage of Class B liquids is determined by the material’s flash point, the lowest temperature required for the liquid to produce a vapor that can propagate a flame. Programs must evaluate the MSDSs or SDSs of each substance to ensure that their handling and storage are in compliance with all OSHA laws and regulations. Flammable liquids are common in necropsy, surgery, and diagnostic areas of an animal facility. Smaller quantities of Class B liquids can be stored openly in the laboratory or facility; however, larger quantities will require storage in explosion-proof cabinets or refrigerators.

Noise Hazards

As stated above under the “Hearing Protection” section, animals and the equipment used for their care may produce sufficient noise to be considered a hearing hazard. Small rodent species rarely pose a noise hazard, larger species (e.g., dogs, pigs, and nonhuman primates) can create enough noise during routine husbandry to pose a serious threat. This is also true for many areas of an animal facility housing noise-generating equipment (e.g., cage washers, pressure washers, and vacuums). The magnitude of the problem is equated with the number of animals present, the acoustics of the room they are housed in, and the required personnel exposure time.

Depending on the acoustics of the room and the nature of the sound generated by the animals or equipment, engineering controls should be considered prior to requiring hearing protections in the area. The magnitude of sound generated can often be dampened by modifying the room acoustics by varying the room surfaces or other structural relationships. Unfortunately, many common sound-dampening surfaces are unable to be sanitized and are permeable to moisture and dirt. The net result is that they are unusable in the animal facility. That being said, removable and sanitizable acoustic panels (e.g., Soundbreak™) have been used successfully in animal facilities to decrease noise levels by up to 10 dB.

Sharps Hazards

Sharps hazards can be found throughout the animal laboratory and facility environment. Inappropriately handled needles, syringes, pipettes, scalpels, broken glass, and other sharp equipment (e.g., damaged caging) can result in traumatic tissue injuries. In addition to the tissue trauma, these injuries can also carry a risk of contamination from pathogenic, zoonotic, and chemical agents. Although minimizing the use of sharps is the idea method for reducing this hazard, it is critical that personnel be trained on how to safely handle and dispose of sharps. The disposal of sharps must be in compliance with all local regulations and policies. The use of appropriately labeled puncture-resistant, leak-proof containers for the disposal of sharps is imperative. It is recommended that needles not be recapped, bent, cut, or removed from syringes, and one should never attempt to compact the contents of the container. Many products are marketed today to aid in the prevention of needle sticks and sharp hazards. For example, needle and scalpel shields, which are integral to the needle or scalpel itself, can shield the point or edge to protect personnel once the procedure has been completed. If recapping a needle or removal of the scalpel blade from the scalpel handle is necessary, personnel should be trained on the appropriate method to be used, for example, using a one-handed technique to hold the syringe with attached needle while picking up the needle cap from a flat counter surface. Scalpel blades should never be removed from the handle by hand. The use of a long needle holder or hemostat to grasp and remove the blade is a safer alternative.

Bites, Scratches, and Other Animal-Related Physical Injuries

Although mostly preventable, potential hazards related to animal bites, scratches, kicks, and crushing injuries are ever present in the laboratory animal environment. Animal-related hazards fall into two broad categories, physical and biological. Physical injuries are the result of the mechanical damage to tissue caused by an animal’s bite, scratch, or direct trauma. Biological injuries are secondary to the inoculation of the wound site with microbial pathogens or zoonotic agents present in or on the animal’s mouth, skin, or nails (e.g., B-virus, rabies virus, and methicillin-resistant Staphylococcus aureus). Most animal-related injuries are the result of direct human animal contact during periods of animal transfer, restraint, or other procedure.

The proper handling and restraint of an animal is the most effective way to protect both the personnel and animals. Chemical restraint is often used to provide a safe working environment for both personnel and animals. When chemical restraint is not possible or practical, consideration should be given to acclimatizing the animal prior to the procedure using positive reinforcement training and desensitization techniques. Personnel working with awake animals must be trained in the normal behavior of the species, as well as their behavior under distressful situations. Training on the appropriate restraint techniques for the species, coupled with appropriate PPE, will help prevent physical injury. When working with animals, it is important to control as many of the environmental variables as possible, while insuring the humane handling of the animal. Ideally, the environment should be quiet and free from distractions. All required restraint equipment should be in good working order and readily accessible prior to working with the animal. Animals not previously acclimated to being restrained often become defensive and aggressive. Personnel should remain calm and move smoothly with confidence and purpose, while trying to anticipate the animal’s reaction and movements.

Various bite-resistant gloves manufactured out of Kevlar^® and/or stainless steel mesh are on the market today. Many of the gloves can be worn over moisture-impermeable gloves or under other protective gloves to reduce punctures secondary to animal bites. When working with some species (e.g., nonhuman primates), arm-length, bite-resistant gloves, usually manufactured of leather or a similar material, should be used to protect both the hand and forearms. It should be noted that protective gloves may not prevent the animal from biting or causing injury, but they are effective in preventing the bite from breaking the skin. The main disadvantage of most gloves is that they greatly reduce the tactile ability and mobility of the user.

All animal bites, scratches, and other related injuries should be taken seriously, and a determination should be made by trained occupational medical personnel whether subsequent treatment of the injury is required. Animal-related injuries should be logged, tracked, and periodically reviewed by program management and safety personnel. This review should identify predisposing factors and possible training gaps and then stimulate program modification to improve injury awareness and prevention efforts. Retraining of current personnel may also be required to prevent reoccurrences.

Allergens

Workers may develop allergic reactions to an animal protein, also referred to as an allergen. These allergens are found in dander, hair, urine, and saliva. Some personnel working with animals become sensitized over time, whereas many never become sensitized. Those who develop allergic reactions often do so within the first 12 months of contact with an animal at home or in the workplace. In rare situations, individuals may not display signs of developing an allergy for several years. The earliest symptoms typically consist of upper airway and skin complaints, such as nasal congestion or stuffiness, a “runny” nose with nasal drainage, sneezing, red and irritated eyes, skin itching, and hives. More advanced cases display lower airway findings, such as coughing, wheezing, shortness of breath, asthma, and in rare circumstances, life-threatening anaphylaxis. The proposed mechanism for these reactions is an immunological and physiological sensitization to specific animal proteins (allergens). Animal allergens can be carried through the air and potentially contaminate all surfaces within an animal facility or animal laboratory. Allergens tend to stick to fur, dander, bedding, and dust. Individuals working directly with animals or in an area contaminated by animal allergens can carry the allergens out of the area on their hair and clothing. Exposure to antigens can be through inhalation of airborne particles, ingestion, or direct contact with the skin or eyes.

Although all animal proteins can be allergenic, some species may pose more of a problem than others. Rabbit and cat allergies are common, whereas allergic reactions to nonhuman primates and aquatic species are less common (NRC 1997). Several factors are associated with an individual’s risk of developing an allergic reaction: the individual’s immune system, and the intensity, frequency, and route of exposure to the animal allergens. Some activities have a higher RoE than others, for example, cage changing. The worker at greatest risk for developing an allergic reaction to laboratory animal proteins is the worker who has a history of allergic reactions to household pets. Individuals with a personal history for asthma, seasonal sinus problems, eczema, and other allergies are also at increased risk for developing an allergic reaction to laboratory animal proteins.

Individuals entering a laboratory animal program should be evaluated for existing animal-related allergies and educated on protective measures. The goal in the workplace is to minimize the chances that workers will inhale or have skin contact with animal-related allergens. Allergen risks can be minimized or eliminated by the use of appropriate engineering controls, such as air containment devices (e.g., biological safety cabinets and chemical fume hoods) and waste handling equipment (e.g., HEPA-filtered bedding dump stations). Respiratory exposures can also be further controlled by housing animals in filter-topped cages and working in a well-ventilated area, such as a room with nonrecirculating room air or near a fume hood. The Guide states that PPE should be used to supplement but not to replace engineering and process controls.

In animal facilities and laboratories using animals, signage that identifies hazards should be clearly posted (Figure 14.5). Policies and procedures should be developed to minimize the environmental burden of the allergens through the decontamination of work areas and, where possible, working with animals in a biological safety cabinet or fume hood. The use of containment caging systems such as microisolator caging has also helped to reduce the environmental burden of allergens. To prevent allergens from leaving the facility or animal laboratory, consideration should be given to working in a negative-air-pressure room and ensuring that PPE (e.g., lab coats) are not worn outside of the area. Ideally, lab coats should be disposable. If nondisposable coats are worn, they should be commercially laundered on a frequent basis.

Figure 14.5

Example of animal hazard signage.

Standard operating procedures should promote the frequent washing of hands and forearms with soap and water while working and prior to leaving the area. Although alcohol-based hand rubs can be used to reduce skin pathogens, they are not effective for allergens and are not a substitution for hand washing with soap and copious rinsing with free-flowing water.

Most individuals do not require respiratory protection when working with or around animals, although a dust or mist face mask may be helpful to reduce exposure to antigens and larger particles, such as hair and dust. In situations where respiratory protection from particulates is required, the use of a disposable filtering face respirator, such as an N-95, or other negative-pressure respirator, such as a PAPR, can provide the needed protection. Individuals using an N-95 respirator or other respirator should be enrolled in the institutional respiratory protection program. Contact allergies can be prevented by protecting eyes and exposed skin with appropriate PPE (e.g., goggles, long sleeves, and gloves).

Zoonotic Diseases

Many of the animals used in the laboratory can harbor potentially zoonotic infections. The likelihood of an animal possessing a zoonotic disease is greatest in wild-caught or random-source animals, where historical information and health data are minimal or lacking. Today, many animals can be procured from captive breeding colonies with a long history of effective programs of disease detection, diagnosis, treatment, and prevention. Using animals from colonies with a known history and disease status, coupled with the development of appropriate standard operating procedures for PPE and animal handling, has helped to make the transmission of zoonotic diseases in the modern laboratory animal facility a rare occurrence.

Although the transmission of zoonotic diseases is rare, some animals must be obtained from the wild or from random sources, and some zoonotic diseases are hard to detect or eliminate from captive-bred animals. A few notable examples are B-virus in Old World macaques, Q fever and contagious ecthyma in small ruminants, cat scratch fever in felines, and mycobacteriosis in fish and frogs. In addition, when working with animals believed to be free of zoonotic diseases, care must be taken not to introduce potential zoonotic agents through the use of contaminated tumors, cell lines, biological agents, or other products. Disease-free colonies have also been contaminated by the inadvertent introduction of feral animals or food or bedding that has been contaminated prior to use.

To prevent the transfer of zoonotic agents, wound care of animal injuries is of critical importance. Depending on the agent in question, programs should develop standard operating procedures for the first aid of wounds and in some cases mucous membrane contaminations. These procedures should be developed in consultation with both medical and safety specialists who are knowledgeable of the potential zoonotic risks associated with each species used within the program. The procedures should address both the immediate care to be provided at the time of the injury and any required follow-up care.

Detailed information on potential zoonotic agents associated with laboratory animals can be found in many publications and reports (NRC 1997; Fox et al. 2015). The following provides a brief overview of the most important zoonotic pathogens associated with common laboratory animals. In addition, Table 14.5 to Table 14.15 provide suggested guidelines for procedures and PPE used within the program at the NIH in Bethesda, Maryland. It must be noted that the suggested PPE outlined in the next sections represents only the guidance provided as a framework for the establishment of best practices. The guidelines were compiled by a team consisting of laboratory animal veterinarians, facility managers, and safety and occupational medical specialists. The guidelines were subsequently adopted by the NIH Animal Research Advisory Committee.

Nonhuman Primates

Although humans and nonhuman primates share many of the same diseases (Table 14.5), the pathogenesis of an organism can vary widely between humans and other primates. An organism can be relatively asymptomatic in one species, while having devastating consequences in another. For example, B-virus can produce a life-threatening disease in humans, while in Old World macaques it produces a mild clinical disease similar to human cold sores secondary to human simplex virus. While most nonhuman primates are extensively tested in quarantine or originate from captive-bred colonies, these animals can still harbor zoonotic diseases. In addition, the nonfixed tissues from nonhuman primates can carry potential pathogens and require special handling. Therefore, it is critical for a program to develop a dynamic training program to educate personnel on the potential hazards and steps required to protect their safety and health.

TB can be a devastating disease in both humans and nonhuman primates. Ideally, a program should be implemented for the routine testing of both the individuals working with nonhuman primates and the nonhuman primates used within the program. The prevalence of TB in both humans and animals is high in many parts of the world. Recently, the United States has experienced the smallest decline in more than a decade in the number of TB cases, as well as an increase in the number of multiple-drug-resistant TB strains (http://www.cdc.gov/tb/publications/factsheets/statistics/TBTrends.htm). Although vaccination is used in some parts of the world in both animals and humans, it does not prevent infection, but only the growth of the organism and development of clinical disease. Therefore, vaccination is not recommended or used as a method of control in the United States. The foundation of most TB control programs is the testing of both humans and animals using a tuberculin sensitivity skin test. Programs should develop standard operating procedures for the testing of staff and animals, to include the methodology, test frequency, test interpretation, and handling of positive animals. Because false-positive skin tests are possible, consideration should be given to retesting using the same or a different site and/or methodology.

Measles (rubeola) is a highly communicable disease in humans, New World, and Old World nonhuman primates (Fox et al. 2015). Outbreaks arise in nonhuman primates from contact with humans infected with the virus or humans who have carried the virus from home on their body or clothing. It has been reported that the measles virus can survive in the external environment for approximately 4 days (Walther and Ewald 2004). Therefore, prevention programs should stress the importance of vaccinating the workforce and educating individuals of the risk they pose to nonhuman primates if they have come in contact with an individual who has measles. Depending on the availability of a vaccine, programs should also consider the vaccination of nonhuman primates. Whether vaccinating humans or animals, it is important to determine if a protective titer had been reached through subsequent serology testing.

B-virus is enzootic among monkeys of the genus Macaca and causes minimal morbidity in its natural host. In contrast, infections in humans, New World, and other Old World monkeys are often fatal and present with rapidly ascending encephalomyelitis. Although this infection remains an uncommon result of macaque-related injuries, the increase in the use of macaques for research on simian immunodeficiency virus (SIV) and other potentially stressful conditions has expanded the number of opportunities for human exposure. Like the human herpes simplex virus, B-virus can reside in the nervous system, where it becomes latent and is only shed when the animal becomes stressed or the immune system suppressed. It is also important to remember that B-virus infection can also occur subsequent to exposure to nonfixed macaque tissues and products (e.g., brain, spinal cord, nerve, and cell cultures).

B-virus can produce oral or urogenital lesions in macaques, and the virus has been found in ocular secretions and saliva. Transmission is commonly through direct bites and scratches, but airborne droplets can pose a splash hazard through the exposure of mucous membranes. It is also important to remember that injuries with inanimate objects contaminated with the virus (e.g., needles, scalpels, and cages) can also pose a hazard risk. Although serologically B-virus-negative macaques can be procured today, as many are bred in virus-negative captive breeding colonies, it is critical to remember that all macaques must be handled as though they are potentially infected because viral shedding is intermittent and viral serology may not accurately reflect the animal’s viral status, even with repeated testing.

The development of appropriate bite, scratch, and splash exposure care policies, procedures, and training on the handling of bites, scratches, and splashes of body fluids from macaque monkeys or other injuries from equipment contaminated with body fluids is critical to ensuring the health and safety of individuals working with these animals. The adequacy and timeliness of wound decontamination procedures are the most important factors determining the risk of infection after exposure to B-virus (Cohen et al. 2002). Thorough cleaning within 5 minutes of injury or exposure is the best means of preventing B-virus contamination from progressing to actual infection. Studies have demonstrated that B-virus may enter host cells within 5 minutes of exposure. Therefore, sponge scrubbing the wound with povidone-iodine or chlorhexidine surgical scrub under running water for 15 minutes is recommended. After the 15-minute scrub, the wound should be rinsed thoroughly with water. For splash exposures to the mucous membranes of the eyes, mouth, or nose, the exposure site should be flushed with water or saline for 15 minutes. Following the cleaning or flushing of the exposed area, personnel must report to a health care professional who is knowledgeable on B-virus and the associated hazards.

It is recommended that a program using Old World nonhuman primates develop a “macaque bite, scratch, and splash kit.” These kits should be located in convenient areas throughout Old World nonhuman primate work areas. The kits should be portable, self-contained units that include a list of instructions on how to use the kit, as well as the following items: (1) iodine and/or chlorhexidine surgical scrub brushes, (2) emergency room directions and instructions for emergency physicians, (3) a small quantity of oral antiviral medication to be taken as directed by a physician, and (4) viral culture swabs and media to be used by emergency personnel to test the wound. Following any human exposure, it is recommended that a complete physical be conducted on the involved animal by trained veterinary personnel, including serological testing.

Measures to prevent B-virus exposures center on the development of standard operating procedures to prevent macaque bites, scratches, and splashes through appropriate animal handling and PPE. A program should develop guidelines for ranking the potential hazard risk associated with various activities related to the husbandry and use of macaques in research (Table 14.6). Each risk level should be associated with the use of appropriate PPE for each activity. It should be noted that mucous membrane protection is defined as a device or combination of devices, which protect the mouth, nose, and eyes from splash or droplets, such as an approved full-face shield, approved safety glasses or protective glasses plus surgical face mask, approved surgical face mask and eye shield combination, form-fitting goggles plus a surgical face mask, or a PAPR. Approved full-face shields provide sufficient protection above the shield to prevent droplets from running down into the eyes and adequate side protection to prevent material from splashing into the eyes or mouth (Figure 14.6). Approved safety glasses or protective glasses must also meet the same requirement to protect the eyes from running droplets and side splashes. Because of individual variations in the shape of each person’s head and face, face shields and safety glasses may need to be evaluated and approved on an individual basis. In activities where aerosols may be formed and respiratory protection required, protection is defined as a device or combination of devices that protects the mouth, nose, eyes, upper airways, bronchi, and lungs from splashes, droplets, and aerosols. Respiratory protection includes the use of an approved full-face shield plus a surgical face mask or other approved respirator, form-fitting goggles plus a surgical face mask or other approved respirator, or a PAPR. The use of an N-95 respirator or form-fitting respiratory other than a PAPR should be approved through the program occupational medical service due to the potential risk when used by individuals with certain respiratory or cardiac conditions.

Table 14.6

Personnel Protective Equipment Guidelines for Personnel Working in Nonhuman Primate Facilities: Risk Assessment and Suggested PPE.

Figure 14.6

Example of a ratcheted full-face shield with chin guard that provides mucous membrane splash protection from all angles. (From Life Science Products, Chestertown, MD, http://lspinc.com/.)

Rodents and Rabbits

Zoonotic diseases associated with rodent and rabbit use in the modern animal research laboratory and animal holding facility (Table 14.7) are uncommon due the availability and use of commercially available specific pathogen-free animals. In addition, the development of facility programs and policies for colony health monitoring and the importation and testing of noncommercially available animals and animal products has also helped to prevent the introduction of zoonotic agents into research colonies. In many situations, the inadvertent introduction of feral animals or material contaminated by feral animals (e.g., feed and bedding) represents one of the more common routes of introduction of pathogens.

Table 14.7

Relevant Zoonotic Diseases of Rodents and Rabbits.

It should be noted that the PPE recommended for rodents and rabbits (Table 14.8) provides personnel protection not only from potential zoonotic agents, but also from potential allergens, as outlined in the “Allergens” section above. The use of hair bonnets, lab coats, and gloves may also potentially protect specific pathogen-free animals from diseases that personnel may carry on their cloths, hair, or hands from outside of the facility. That being said, it has been recently identified that the donning of shoe covers was a potential source of contamination and that wearing shoe covers did not significantly impact the health of the colony (Hickman-Davis et al. 2012). In addition, not donning hair protection was found to result in the transport of rodent allergens on the hair of personnel working with rodents (Krop et al. 2007).

Table 14.8

Protective Clothing Requirements for Personnel in Rodent and Rabbit Facilities: Risk Assessment and Suggested PPE.

Carnivores

The most common carnivores used in research are dogs, cats, and ferrets. The most common zoonotic agents seen in laboratory carnivores in the United States are rabies, enteric pathogens, and parasites (Table 14.9). Many of the zoonotic diseases of carnivores can be prevented by vaccination (e.g., rabies and leptospirosis) and appropriate health management (e.g., parasite checks). Here again, the PPE (Table 14.10) serves to prevent the transmission of disease in two directions, from animals to humans and from humans to animals. It is common for personnel to keep dogs, cats, and ferrets as pets at home, and their health status may vary from that of the animals maintained at work. Therefore, program management should be aware of the pets kept at home by their staff and develop policies and procedures that protect the health and welfare of the research colony.

Table 14.9

Relevant Zoonotic Diseases of Laboratory Carnivores.

Table 14.10

Protective Clothing Requirements for Personnel in Carnivore Facilities: Risk Assessments and Suggested PPE.

Ungulates

Zoonotic disease associated with ungulates (Table 14.11) used in research is often dependent on the source of the animals and policies and procedures used to manage the research herd. Closed herds with appropriate vaccination and herd health programs may present a minimal risk, whereas herds maintained outside in unprotected open areas may present a higher risk. Q fever is prevalent in sheep throughout the United States, and sheep are the species most associated with outbreaks of the disease in laboratory animal populations. The PPE used with ungulates (Table 14.12) will vary with the risk level, husbandry style, and nature of contact.

Table 14.11

Relevant Zoonotic Diseases of Ungulates.

Table 14.12

Protective Clothing Requirements for Personnel in Ungulate Facilities: Risk Assessments and Suggested PPE.

Fish and Frogs

Zoonotic diseases associated with fish and frogs used in research are infrequent (Table 14.13), but can occur. The availability of commercially available animals of known health status has helped to decrease the zoonotic risk. Mycobacteria infections of the skin are one of the more common zoonotic diseases seen in the laboratory environment. Care should be taken to use gloves (Table 14.14), especially if there are any breaks in the skin. The thorough washing of hands and arms when leaving the aquatic holding area is recommended. Although splash hazards to the eyes and mucous membranes are not normally problematic, when occurring, the area should be thoroughly flushed with running water for 5 minutes.

Table 14.13

Relevant Zoonotic Diseases of Laboratory Fish and Frogs.

Table 14.14

Protective Clothing Requirements for Personnel in Fish and Frog Facilities.

Hazards Associated with Animal Study Protocols

All animal study protocols (ASPs) should be closely examined to identify and address potential hazards associated with the protocol. There may be multiple classes of hazards (infectious, radiologic, chemical, and physical) associated with each ASP, and they may not be fully recognized by the investigator. Each ASP should be closely reviewed by a health and safety professional prior to final Institutional Animal Care and Use Committee (IACUC) approval to ensure that appropriate interventions, mitigations, and disposal procedures are fully addressed and understood by all parties.

Biological Agents with Human Pathogen Potential

There are special considerations for working with experimentally infected animals housed in indoor research environments. Institutional management must provide facilities, equipment, staff, and established practices that reasonably ensure appropriate levels of environmental quality, safety, security, and care for the laboratory animal while protecting workers, the environment, and the public from the infectious agents themselves. The vivarium is considered a type of specialized research laboratory, and biosafety levels have been described for working in these areas with animals that have been experimentally infected. Biosafety levels are appropriate combinations of facility features, safety equipment, and operations and procedures that are used to ensure necessary containment of the infectious agent during the conduct of the research. In the animal facility, biosafety levels are referred to as ABSLs 1–4 because the specialized nature and complexities of animal research are addressed in conjunction with the need for biological containment. Biosafety levels increase based on the infectious agents in use and the risk assessment of the procedures to be performed. An overview of these requirements is presented in Table 14.16. For a full description of ABSLs, the reader should consult the current edition of Centers for Disease Control and Prevention (CDC)/NIH publication entitled Biosafety in Microbiological and Biomedical Laboratories.

Table 14.16

Summary of Recommended Animal Biosafety Levels for Activities in Which Experimentally or Naturally Infected Vertebrate Animals Are Used.

These recommendations assume that laboratory animal facilities, operational practices, and the quality of animal care meet applicable standards and regulations (e.g., the Guide [NRC 2011a] and laboratory Animal Welfare Regulations [AWAR 2013]) and that appropriate species and numbers of animals have been selected for animal experiments.

In Canada, similar containment levels (CLs) are employed but are more heavily regulated by the government. The reader is referred to Canadian Biosafety Standard (CBS), Second Edition, 2015 (http://canadianbiosafetystandards.collaboration.gc.ca/cbs-ncb/index-eng.php), which is a harmonized national standard for the handling and/or storing of human and terrestrial animal pathogens and toxins based on pathogen risk groups 1–4 (RGs 1–4) established by the World Health Organization (WHO) (Table 14.17).

Table 14.17

World Health Organization Pathogen Risk Groups.

Based on risk assessment, CLs 1–4 are assigned. Small and large animal zones may be included within laboratories meeting CLs 1–4. The reader should consult the Canadian Biosafety Handbook (CBH), Second Edition, 2015. The CBH is a companion document to the CBS and provides core information and guidance to aid in achieving the biosafety and biosecurity requirements outlined in the CBS.

Working with Recombinant or Synthetic Nucleic Acid Molecules

Guidance for working with recombinant or synthetic nucleic acids in animals can be found in the NIH Guidelines for Research Involving Recombinant or Synthetic Nucleic Acid Molecules (NIH Guidelines 2016) (http://osp.od.nih.gov/sites/default/files/resources/NIH_Guidelines.pdf). These guidelines must be consulted when planning work involving recombinant or synthetic acid molecules. The use of the NIH Guidelines is also risk assessment based, relying on the WHO RGs as a starting point. Using the Biosafety in Microbiological and Biomedical Laboratories and the NIH Guidelines as companion documents can be problematic because nomenclature for CLs has not been harmonized. For example, when experiments involve whole animals in which the animal’s genome has been altered or which involve viable microbes containing recombinant DNA (other than viruses that are only vertically transmitted) that are tested on whole animals, a minimum containment of BL2 or BL2-N is required. This nomenclature, in practice, equates to BSL-2 and ABSL-2. However, in cases where the introduction of recombinant DNA into animals might lead to the creation of novel mechanisms or increased transmission of a recombinant pathogen or production of undesirable traits in a host animal, higher-level containment conditions should be implemented. When experimenting with animals that contain sequences from viral vectors that do not lead to transmissible infection as a result of complementation or recombination in the host animal, BL1 or BL1-N containment may be used (BSL-1 and ABSL-1, respectively). The Institutional Biosafety Committee (IBC), in each institution, serves as the governance and review body for the oversight of recombinant work and should be consulted prior to beginning this type of work involving animals.

A number of agencies within the U.S. government oversee different aspects of work with recombinant nucleic acids and human pathogens. These include

• NIH Guidelines
• EPA Regulations
• U.S. Department of Agriculture (USDA) Animal Plant Health Inspection Service (APHIS) Regulations
• FDA Regulations
• Commerce Department Regulations
• Select Agent Rules
• HHS Synthesis Screening Guidance for Providers of Synthetic Double-Stranded DNA

The CBS refer to the NIH Guidelines for review and risk assessment assistance regarding recombinant nucleic acid work. In the EU, the following directives are salient regarding genetically modified microorganisms (GMMs) and should be consulted:

• Directive 90/219/EEC on contained use of GMMs
• Directive 2001/18/EC on deliberate release into the environment of GMMs

Use of Radionuclides in Animal Research

Typically, very small quantities of radioactive materials are used in animal research, and the risk to an employee’s health is low. This is not to say that radiation protection in these situations is inconsequential; however, it is typically a lesser concern than the other risks associated with animal research. In all cases, the animal study proposal must be reviewed by the institution’s radiation protection office or health physicist and should specifically address the radioactive conditions permitted, personal hygiene precautions to be taken by animal care personnel, and instructions for cage cleaning and the collection, labeling, and disposal of radioactive wastes.

Personal protection used with radioactive materials in animal research is usually similar to that used routinely in animal care. The use of gloves, laboratory coats, and other protective clothing minimizes the chances for the ingestion or absorption of radioactive materials when working with animals. The protocols should specify the training that must be provided to all personnel regarding the specific radiation safety requirements for the tasks to be performed. This training must be directly related to the duties of the individual, and commensurate with the risks.

Use of Hazardous Chemicals and Drugs in Animal Research

Potentially hazardous chemicals and drugs are commonly found in animal research and should be specifically addressed in animal study proposals. The ASP must identify potential hazards of the chemicals and drugs to be used, communicate information concerning the hazards to those involved in the conduct of the research, and describe the appropriate protective measures to employees. Alternatively, standard operating procedures can also be used to communicate the required information. Chemical safety in research involving animals is governed by numerous local, state, and federal regulations, as well as numerous “standards of practice.” Standards of practice are guidelines used to determine what should or should not be done in a given situation. In the case of safety and health practice, this guidance may be issued by other than regulatory agencies, such as the National Institute for Safety and Health (NIOSH), CDC, and the National Research Council. These guidelines may also be published and widely distributed in authoritative texts such as Prudent Practices in the Laboratory: Handling and Management of Chemical Hazards (NRC 2011b). These accepted standards of practice may be considered regulatory under OSHA’s “General Duty” clause that requires a workplace free of recognized hazards (Thomann 2003). Some chemicals may be explicitly regulated by OSHA in a specific health standard, such as formaldehyde or ethylene oxide. Most chemicals in laboratories and animal facilities are regulated more generally through 29 CFR 1910.1450”“Occupational Exposure to Hazardous Chemicals in Laboratories. This regulation specifically addresses the unique and variable aspects of the laboratory environment, including the animal facility. In any case, it is the employer’s responsibility to minimize exposures to hazardous chemicals in the workplace.

In preparing an ASP, pertinent chemical safety information may be found on MSDSs or SDSs, pharmaceutical inserts or information, the Registry of Toxic Effects of Chemical Substances (RTECS), or similar services.

Certain common and ubiquitous chemical agents may be overlooked when considering usage in an animal facility and may not be addressed directly in an ASP. Consider the use of disinfectants and sterilants. By definition, these compounds are “poisons” and must be handled responsibly. They are used to destroy or irreversibly inactivate pathogenic microorganisms on inanimate surfaces (Van Swearingen and Shoaf 2001). Many different classes of disinfectants and sterilants are found and used in animal care facilities, and each has associated potential health effects, standards and recommendations for safe use, and methods for exposure control. Care should be taken during use of these compounds.

Anesthetic gases are another potential chemical hazard often present in animal facilities and during veterinary procedures. The anesthetic gases and vapors that leak into the surrounding room during medical procedures are considered waste anesthetic gases. Some potential effects of exposure to waste anesthetic gases are nausea, dizziness, headaches, fatigue, and irritability, as well as sterility, miscarriages, birth defects, cancer, and liver and kidney disease, among operating room staff or their spouses (in the case of miscarriages and birth defects). Employers and employees should be aware of the potential effects and be advised to take appropriate precautions. Scavenging devices should be used to capture waste gases, limiting occupational exposure. Routine surveys or leak tests of each anesthetic breathing circuit (machine, scavenging device, tubing, etc.) or location should be performed and documentation retained for presentation to AAALAC International site visitors, safety specialists, and so forth, as necessary. Records of certification for other safety equipment, including fume hoods, biosafety cabinets, downdraft tables, and necropsy tables, should also be kept available for inspection.