Chapter 14: Safe Handling of Laboratory Animals
This chapter covers the hazards associated with laboratory animal handling, mandatory and recommended control practices, the institutional structures that UNC-Chapel Hill has in place to assure animal welfare, and requirements for using hazardous agents in laboratory animals.
- the equipment, materials and practices used in routine animal husbandry
- animal contact, directly or indirectly
- the techniques or materials (e.g., biohazardous substances) used during the course of animal experimentation
Regardless of the source of a hazard, you must take several basic measures to reduce the risk of personal exposure. These include understanding the hazards you are likely to encounter during animal care and use, using properly designed and maintained facilities and equipment to minimize exposures, wearing appropriate personal protective equipment (PPE), and demonstrating the technical proficiency necessary to accomplish experimental manipulations or animal care procedures in a safe and humane fashion.
If you plan to use vertebrate animals in your work, IACUC requires successful completion of the online IACUC Orientation course, as well as additional courses for specific techniques or species. Refer to the IACUC Training and Compliance website for more information. OACU, IACUC and the Division of Laboratory Animal Medicine (DLAM) work in collaboration with EHS and the University Employees Occupational Health Clinic (UEOHC) to ensure that appropriate expertise is involved in program guidance and the timely exploration and resolution of new problems.
As part of your mandatory orientation course, you are required to submit the Research Animal Handler Questionnaire. The UEOHC reviews this form and performs a risk assessment based upon relevant individual health history or concerns, the species of animals you use, the extent of animal contact, and the experimental agents or procedures used in the animal studies. UEOHC also requires that you submit a completed Worker Registration Form to EHS.
Based upon this assessment, the UEOHC might recommend additional vaccinations, modifications in the use of PPE, or possibly even work re-assignment to other types of duties. In addition, the UEOHC serves as a primary care provider for workplace injuries and accidents involving laboratory animals or laboratory animal facilities. Contact the UEOHC promptly at 919-966-9119 if you have health-related concerns due to working with laboratory animals.
- Burn injuries due to working around cage washers, autoclaves, or other sources of hot water or live steam
- Crush injuries or lacerations from moving caging equipment, operating sanitation equipment, or working with intractable large animals
- Musculoskeletal injuries (strains, sprains or fractures) due to the use of improper technique in lifting or moving heavy equipment, or improper restraint and handling of large animals
- Slip and fall injuries from walking on wet flooring
- Hearing impairment resulting from work around loud machinery or animals
- Visual impairment from direct trauma (equipment), splash exposure (detergents, disinfectants, or particulate matter) or exposure to ultraviolet light resulting in corneal damage
- Skin irritation or contact dermatitis from exposure to chemicals used in cleaning, latex or talc allergy, or in experimental procedures in the animal facility
- Respiratory exposure to irritating vapors, aerosols or particulates from working with disinfectants and bedding materials
- Needlestick exposures from attempts to recap hypodermic needles, improper injection technique, or delay or improper disposal of used needles
Personal awareness of hazardous conditions or factors in the environment is critical to avoiding these types of injuries. You should develop the habit of assessing the environments in which you work. Consult with EHS, DLAM, or OACU personnel about the identified hazards in particular work areas, and effective work practices proven to prevent incidents.
All DLAM facilities provide mandatory outerwear, which you must put on before entering animal housing areas or procedure rooms. Mandatory items include gloves, facemask, shoe coverings, and disposable lab coats (Figure 14.1). Most facilities also require a hair covering, and some require (and provide) disposable coveralls in place of the lab coats. This outerwear is primarily for the protection of the housed animals, but it also provides barrier protection to the wearer by preventing deposition of animal allergens onto the wearer’s clothes or hair.
Additional equipment is necessary when personnel could be exposed to zoonotic pathogens or aggressive animal behavior (Section V). Sturdy, closed-toe shoes are strongly encouraged in DLAM facilities, and are required in laboratory environments. Based on the types of research, animals, or exposure potentials, other animal housing areas might require face shields, splash goggles, respirators, fully encapsulating suits, hearing protection or other equipment. Obey all PPE postings in DLAM and satellite animal facilities. Consult with DLAM facility supervisors to determine if there are entry restrictions to particular rooms due to animal infections such as pinworms. Obey all room order postings, which help prevent personnel who have been in “dirty” areas of the facility from entering “clean” animal rooms.
Special attention and training is necessary if you are involved in the handling and restraint of large animals, especially non-human primates. In addition to posing a bite and scratch hazard, non-human primates can be challenging and difficult to handle safely because of their remarkable strength, dexterity, intelligence, and tenacity. Non-human primates have caused injuries when they have grabbed and pulled neckties, loose-fitting lab coats, or long hair of unsuspecting personnel. When compatible with the experimental conditions of animal use and/or the clinical condition of the animal, consider chemical immobilization of many non-human primate species to enable safe animal handling and to reduce the risk of injury.
DLAM posts specific PPE requirements in the housing areas for working with macaque monkeys. These requirements include the DLAM outerwear mentioned earlier, plus safety (splash) goggles; a face shield is also required for close contact with conscious animals. During the quarantine period, before the monkeys are known to be free from tuberculosis, you must use a NIOSH certified, fitted N95 respirator at a minimum. Refer to Chapter 5 for more details about respiratory protection.
Animal bites continue to be a common occurrence among research personnel, and you should take them seriously even when there is little tissue damage. If a laboratory animal bites you, seek prompt medical review of the wound and tetanus immunization status by UEOHC. Complete the employee accident form, Form 19, and supervisor form. If warranted, the animal will receive a veterinary evaluation.
Animal bites also prompt a veterinary review of the animal handling circumstances to ensure that you used proper animal handling techniques. A specific, detailed protocol is in effect for bites, scratches, or mucous membrane exposures involving some monkey species due to the Herpes B virus, an agent that can cause fatal infection. Other specific viral agents that can be involved as wound contaminants include rabies virus (all mammals), Hantavirus (rodents), lymphocytic choriomeningitis virus (rodents) and orf virus (sheep and goats). Numerous bacterial agents and at least one fungal agent have also been recorded as wound contaminants resulting in serious localized or systemic infections.
Although rodents, rabbits, and cats are most often incriminated in cases of laboratory animal-associated allergy, other mammals and birds also can be involved. Work practices that minimize contact with animal proteins reduce risk for development of allergy. For example, various levels of PPE are available for personnel working with laboratory animals to reduce exposure to allergen. You should wear long sleeve outer garments (e.g., lab coat or disposable coverall) to reduce the exposure of skin to urine, dander, and other allergens. Filtering facepiece respirators may help reduce the exposure of the respiratory tract to allergen; however, personnel with known inhalant allergy should consider the use of a full-face respirator or a powered-air purifying respirator (PAPR), both of which provide ocular as well as respiratory protection.
Allergy history is an important element of the health review conducted by UEOHC for personnel involved with laboratory animal care and use. If you have or suspect that you are developing an animal-associated allergy, consult with the UEOHC to determine the optimal allergy management strategy. Training is available on the EHS website that outlines Lab Animal Allergies.
1. Rodents and Rabbits
The modern conditions of production and care for most laboratory rodents and rabbits have led to the eradication of zoonoses in most of these species. Although contamination of these animals through environmental sources, contact with wild rodents or other infected animals, or through tumors, cell lines, or other biologics used experimentally happens, it is rare. In most circumstances, only wild-caught, laboratory maintained rodents are a high risk for the transmission of zoonotic diseases. Be familiar with several zoonoses associated with rodents and rabbits.
Two serious systemic viral zoonoses have been associated with the use of laboratory rodents. Lymphocytic choriomeningitis virus causes a flu-like disease with neurological complications, and Hantavirus infection produces a disease marked by renal failure and respiratory complications. Other than the bite-associated bacterial infections from rodents (e.g., rat-bite fever) there are few bacterial zoonoses in these species. The rabbit is a potential source for human bacterial pathogens, especially those that cause human diarrheal disease such as salmonellosis.
Rodents and rabbits are also a source for human ringworm infection, usually recognized as a reddened, annular lesion of the skin of the affected individual. A similar focal dermatitis results from infestation with rabbit fur mite and, rarely, other mite species of rodents. The dwarf tapeworm infestation of rodents also is capable of infecting man. The complete absence or extremely low incidence of these agents in laboratory animal populations has obviated our need to adopt intensive health surveillance measures for individuals who work with these species. However, all personnel should use appropriate PPE when working with these species and report unusual illnesses or conditions possibly related to animal contact. The minimal personnel protective equipment recommended for working with small rodents includes particle facemask, latex (or nitrile or other) disposable gloves, safety glasses and a clean lab coat.
2. Dogs and Cats
Source control and sound programs of veterinary care at the vendors’ facilities and at UNC-CH ensure the eradication of most zoonotic infections in these animal species prior to their experimental utilization. Due to financial limitations, it is not practical to rule out all potential zoonoses. In some cases, subclinical infections may go undetected and untreated, posing a risk for the personnel who work with these animals. These can include intestinal bacterial infections (salmonellosis, yersiniosis, and campylobacterosis), systemic bacterial infections (brucellosis, cat-scratch fever, leptospirosis and Q-fever) and intestinal parasitic infections (giardiasis and toxoplasmosis). The dog and cat can also harbor dermatophytes that cause human ringworm and other external parasites capable of infesting humans.
Proper use of PPE can minimize exposure to these zoonotic hazards, and should include long pants (or similar leg protection), lab coat or coverall, facemask, safety glasses and disposable gloves. If you work with laboratory cats not specifically bred for research purposes, consider participation in the rabies vaccination program available through UEOHC.
3. Non-human Primates
The list of zoonotic diseases in non-human primates is long and includes numerous viral (e.g., Herpes B virus, hepatitis A and B, measles and SIV), bacterial (e.g., tuberculosis, salmonellosis, and shigellosis) and protozoal (e.g., giardiasis and amebiasis) diseases, and there are many documented cases of zoonotic transmission. Consequently, non-human primates must undergo an extensive quarantine period to preclude the presence of many of these zoonoses before experimental work with these animals can proceed. Even after release from quarantine, rigorous disease surveillance continues for some agents such as tuberculosis. Personnel must participate in periodic tuberculin testing through UEOHC if they have any non-human primate contact. Personnel who work with macaques must undergo special training concerning the prevention and management of potential exposure to B virus, an agent that has caused many fatalities among laboratory personnel.
University policies expect strict adherence in the use of PPE by all personnel with non-human primate contact. Personnel handling non-macaque monkey species must wear a lab coat (or equivalent), particle face mask, eye protection, disposable gloves and shoe covers when entering housing areas. The more stringent PPE requirements for personnel using macaque monkeys are in the section on Bites and Scratches.
4. Birds and Livestock
Q fever has proven to be an important zoonosis associated with livestock in laboratory animal facilities. Although all ruminants and many other animals are potential carriers, infection of laboratory personnel has most often been associated with pregnant sheep that copiously shed the organisms. The disease causes a flu-like illness, which can progress to a serious systemic infection with heart involvement. Orf, a pox viral disease of sheep and goats, can also infect humans through contaminated wounds producing firm, nodular lesions. Livestock and birds can harbor bacterial zoonoses causing diarrhea in humans. Birds also can shed the agent psittacosis (Chlamydia psittaci), a serious respiratory and systemic disease of humans. Proper use of PPE is essential to minimize exposure to these potential zoonotic hazards. Use respiratory protection compatible with that described for the prevention of tuberculosis when working with pregnant ruminants (Q fever) or birds harboring Chlamydia psittaci.
A more recent, emerging concern is avian influenza virus, with H5:N1 virus receiving the most attention. H5:N1 virus is an influenza A virus subtype that occurs mainly in poultry and wild birds, is highly contagious among birds, and can be deadly to them. H5:N1 does not usually infect people, but infections with these viruses have occurred in humans. Most of these cases have not resulted from person-to-person contact, but instead resulted from people having direct or close contact with H5:N1-infected poultry or H5:N1-contaminated surfaces. Therefore, proper handling, sanitation, and use of PPE can prevent transmission of virus from bird to human.
Depending on the type of hazardous agent used in animal experimentation, you might have to include the following forms in your animal use applications. These forms are integrated into the protocol through the online Application to Use Live Vertebrate Animals (ACAP) system.
In general, the following chemical substances will require the completion of the Use of Chemical Hazards in Laboratory Animals form:
- Any substance that meets the definition of a toxic substance from the OSHA Hazard Communication Standard, meaning that it possesses any of these three characteristics:
- oral LD50 <500 mg/kg in albino rats
- skin absorption LD50 <200 mg/kg in albino rabbits
- inhalation LC50 <2000 ppm or 20 mg/L in albino rats.
- All substances that are known or suspected human carcinogens. This includes formaldehyde-based fixatives used for animal tissue perfusion while the animal is still alive.
- All substances that are known or suspected reproductive hazards.
- All substances classified as cytotoxic/antineoplastic agents.
- All investigational drugs with limited safety or toxicological data.
- All nanoparticles or nanoparticle formulations with limited safety or toxicological data.
- All inhalation anesthetic agents (e.g. isoflurane, sevoflurane, methoxyflurane, halothane, nitrous oxide, ether).
These forms are not required for agents used strictly for animal analgesia, or for injectable anesthetic agents (e.g. ketamine, xylazine, tribromoethanol) used for anesthesia. However, if you use these substances as experimental test agents, rather than for analgesia/anesthesia, and they are either toxic or carcinogenic as defined above, then you must complete a form. Many analgesics and anesthetics are also controlled substances. Refer to Chapter 9: Controlled Substances for more information on the safe use of controlled substances.
- Human blood or body fluids, or other potentially infectious materials, including cell lines and neoplastic tissues.
- Microbial agents capable of causing human illness or infection, including various species of bacteria, viruses, protozoa, rickettsia, etc. Note: If you are using purified, isolated microbial components such as exotoxins or endotoxins (LPS), rather than the entire microbe, the Use of Chemical Hazards in Laboratory Animals form is more appropriate.
- Microbial vectors (such as phages, adenoviruses) used for delivery of genetic materials.
- Microbial toxins (such as cholera toxin, diphtheria toxin) which affect humans and may be shed in animal secretions.
Work with viral vectors and recombinant DNA, gene transfer experiments, and transgenic animals require the approval of the Institutional Biosafety Committee (IBC). IBC forms are integrated into the online Laboratory Safety Plan. To expedite IBC review, submit these forms for approval to EHS before the end of each month, so the IBC can review them at its meeting at the beginning of the month. Refer to Chapter 2: Laboratory Safety Plan for more information about the following forms.
- For recombinant DNA, viral vectors, gene transfer experiments, and transgenic animals created within your lab, use Schedule G: Recombinant DNA of the online Laboratory Safety Plan.
- For transgenic animals created in other labs or institutions, use Schedule H: Use of Transgenic Animals or Plants of the online Laboratory Safety Plan.
For additional requirements for using radionuclides or radiation-producing equipment, consult the EHS Radiation Safety Manual.