4th National Symposium on Biosafety

Chemical Containment in the Animal Care Facility

William Crouse, MS, CIH, CSP and Jeffrey Everitt, DVM
Dept of Experimental Pathology and Toxicology
Chemical Industry Institute of Toxicology
P.O. Box 12137, 6 Davis Drive
Research Triangle Park, NC 27709
919-558-1267

Finally all interested groups need to work together to resolve issues and reduce risks. This includes Animal Care and Use, Safety and Industrial Hygiene, Health Services, Preventative Maintenance and Administration, those who control the dollars. Often times we feel that we are battling each other, but it is important that we understand the other groups perspective. S&IH and Health Services are responsible for the regulations and helping our staff meet requirements. Likewise, they must become familiar with the animal work environment so solutions are practical. The take home message is that we all need to work together as a team!

The use of chemicals in the Animal Care Facility (ACF) involves important safety concerns for personnel and the local environment, necessitating a carefully designed program of containment (Fig 1). Developing and implementing a chemical containment program for an ACF poses multiple administrative and engineering challenges. The ACF often conducts studies where animals are dosed with relatively high concentrations of potentially toxic test agents. Although animal care technicians do not normally constitute the principal investigative staff in animal studies utilizing toxic chemicals, they often form the primary user group exposed to hazardous materials. The exposure of this group to toxic hazards is particularly troublesome because these individuals often have the lowest level of formal educational training in research facilities. Consequently, they may not have sufficient training or background to understand that trivial exposures to the test agent may result in either acute or chronic injury. In addition to safety concerns for investigative and ACF staff, there are experimental and animal welfare concerns associated with test systems and containment device utilization that must be addressed during the design of chemical containment programs. Engineering control methodologies such as chemical fume hoods, although important, may not be sufficient or effective for adequately containing and removing potentially toxic materials from the work area. One should be cautious upon relying solely on blackbox engineering solutions for solving chemical containment challenges.

Containment is a relative term with different meanings according to the perspective of each respective group of professionals (Fig. 2). For the Occupational Health and Safety (OH&S) professional, containment implies protection of personnel, facility, and environment. For the principal investigator and ACF staff member, containment is sometimes thought to refer to protection of the animal and the experiment. Obviously both definitions are mutually correct. Ideally, chemical containment should be maintained during all phases of the study (Fig. 3). By properly containing hazardous agents, employee health and safety,experimental design and integrity are significantly improved.

This article addresses the development of a chemical containment program for an animal care facility through combined administrative and engineering strategies. A successful chemical containment program starts before the experiment begins and is comprised of multiple phases (Fig. 4). The experimental design and protocol development process provides opportunities for the study director to identify personnel who will be handling potentially toxic agents and, in addition, to identify work areas and equipment associated with the use of these hazardous materials. Consultation with OH&S assists the study director in the selection of administrative and engineering controls to protect workers handling the test agent. For a chemical containment program to succeed and continue to improve, a framework for interdisciplinary teamwork must be established among animal care, toxicology, health and safety, engineering/facilities and waste management personnel.

Before using large quantities of potentially toxic materials in dangerous animal procedures such as dosed feed or inhalation toxicology studies, equipment and procedures should be tested. This testing can be performed by planning and conducting small scale trial runs using nontoxic marker compounds under identical handling as would be performed during actual experiments with hazardous materials. Utilization of these marker compounds, such as flourescein mixed in animal feed, allows rapid visualization of potential contamination pathways within the work area and evaluates the ability of personal protective equipment and engineering controls to protect the ACF worker. These approaches, combined with focused employee training and education, have been demonstrated to provide worker protection within environments where toxic materials are routinely used.

Administrative Chemical Containment Strategy

Historically, animal care professionals have applied the so-called keep in-keep out (KIKO) strategy for maintaining microbial protection of animals. These same principles can be used in strategies for the containment of chemicals. One must always remember that keeping toxic materials within spaces using containment aids is not simply a matter of reversing airflows on devices designed to keep materials out of environments. Effective chemical containment and subsequent removal of toxics from the work environment, relies heavily upon a balanced combination and execution of administrative strategies. OH&S professionals believe that there can be no substitute for adequate engineering controls for controlling human exposure to toxic agents in the work environment. Despite this realization, engineering strategies in the absence of an effective administrative program may provide a false sense of security and employee protection.

The primary elements that comprise an administrative chemical containment strategy are: (1 ) development of standard operating procedures; and (2) proactive employee OH&S training program. The ability to identify the need for and establish containment strategies begins with the development and implementation of a clearly written program for handling and using hazardous materials and for hazardous waste disposal. The program may be developed as a dynamic and cohesive series of clearly written standard operating procedures prepared by OH&S professionals. The administrative program created from these standard operating procedures (SOP) should accomplish the paradigm of hazard recognition, evaluation, and control.

Procedures are then reviewed and revised on a continuing basis to reflect current toxicology knowledge and exposure conditions associated with the specific hazardous material under investigation. All elements of the administrative program for chemical containment must clearly exceeds compliance with applicable Occupational Safety and Health Administration (OSHA) 29 CFR 1910 regulations related to substance- specific and general occupational health and safety standards as well as United States Environmental Protection Agency (EPA) regulations affecting waste generation, storage and handling practices.

The next step is to develop an employee hazard communication and hazard identification training program that enables OH&S to communicate important hazard and protection information to employees before the study begins. Hazard identification and communication include understanding the nature of the hazard, relevant methods for detecting its presence and the specific work situations where it can be safely handled. Also, an apriori cradle-tograve study of the test agent should be performed that allows one to track the path of the hazardous material from entry into the work area until it or its metabolites are placed into the waste stream. Effective employee training and OH&S oversight play extremely important roles in minimizing the potential for employee exposure. Workers learn techniques for recognizing, evaluating, and controlling personal exposures to potentially toxic agents. With administrative procedures in place, personal protective equipment and containment devices can be selected based upon the potential hazard of the test agent. PPE, an extremely important administrative control modality, may be defined as those articles of clothing, respiratory and skin protection that when used properly, protect the employee and minimize exposure to potentially hazardous test agents. PPE may be as simplistic as a laboratory coat, chemically resistant gloves and safety glasses or may be a fully encapsulated chemically resistant pressure suit attached to an external supply of purified breathing air. For PPE to perform its function properly, it must be comfortable for the worker to wear over extended periods of time. Otherwise e worker may remove it or not wear it correctly during a critical operation where the exposure potential is high. This is particularly relevant in the ACF, where technical staff may be exposed to hazardous materials while working in hot environments such as the cage wash area. With the development of new and lightweight chemically resistant polymers and fabrics, PPE may be extremely light weight, comfortable and functional One must again realize that PPEis not meant to substitute for proper engineering controls but is to be utilized as a adjunct tool for increasing the degree of employee protection.

Engineering Chemical Containment Control Strategy

The implementation of engineering strategies that eliminate or minimizes employee exposure is a key ingredient in the ACF chemical containment program. As previously mentioned, adequate engineering strategies may be severely constrained by the absence of sound administrative programs. Once in place, developing and implementing good engineering practices become the final tool for optimizing employee and environmental worker protection. Ideally, ACFs are designed and built with the intent of providing maximum contaminant containment and employee protection. Key elements contributing to the safe and efficient operation of an ACF include facility design, mechanical systems, HVAC operation, environmental monitoring systems, and waste handling facilities. Designing safety into the blueprint drawing rather than retrofitting later on is always easier. In many cases, ACFs must either retrofit or upgrade existing engineering controls during studies with highly toxic agents to maximize chemical containment. Before a research study with a potentially toxic agent begins, ACF work areas where the material will be used should be clearly marked on a facility blueprint. Care should be taken to segregate these work areas, thereby minimizing unnecessary movement of toxic materials and/or metabolites through the ACF. OH&S and facility personnel are key to the development of engineering controls .

If an operation has the capacity to generate contamination, local ventilation devices such as charcoal and HEPA-filtered glove boxes and chemical fume hoods are quite effective in containing and removing airborne contaminants. General ventilation techniques focus upon employee comfort parameters such as control of temperature and relative humidity. In no circumstances should general ventilation systems ever be employed as a control strategy for either capturing or diluting airborne concentrations of toxic agents. In all instances, ACF managerial personnel should be familiar with the operation and specifications of their HVAC system, the design of air handling equipment, and maintenance requirements of these systems.

In dosed feed studies, the atmospheric pressure of the work room should be carefully controlled and monitored so it will remain negative relative to the outside corridor. Any leakage of air or contaminant will always flow from the corridor into the room. Such an airflow configuration provents the migration of toxic materials outside the work area. ACF personnel should understand how the placement of animals, cages, racks, and containment equipment in the animal room can affect airflow. Additional engineering controls and features which should be incorporated into an engineering control strategy program include the following:

When operating within the specifications intended for their operation, engineering control systems provide excellent employee and environmental protection from chemical agents. Engineering control systems must be subjected to routine maintenance and monitoring and should always be backed up with built-in redundancy. Whenever possible, multiple levels of containment should be utilized. The form of this multiple containment strategy will be dictated by the type and nature of the experiment and the equipment and facilities available. Combined with a chemical containment administrative program, chemical containment engineering processes will perform optimally providing the maximum degree of containment.

Biological and Animal Welfare Concerns

There are many types of containment devices: individually ventilated racks, specifically designed animal rooms, hoods and safety cabinets, and waste management units. Although these various containment aids provide protection to the employee and the surrounding work area, containment equipment and processes are often not animal-friendly. During the Institutional Animal Care and Use Committee (IACUC) review process, thought should be given to developing flexible, animal-friendly containment strategies. The goal should be to utilize containment equipment that is relatively comfortable for the animal. In many cases, ACF workers will require access to the animal during the chemical exposure so one must consider employing double and triple containment strategies to provide protection from the chemical agent without compromising the assessibility, comfort, and well-being of the animal. Preplanning containment strategies during preparation of the IACUC statement allows OH&S and ACF personnel to devise animal friendly containment strategies that will not compromise worker safety.

Summary

For a chemical containment program to succeed, an interdisciplinary, team-based approach relying upon technical expertise from different groups within the facility must be employed. Worker, work area, and environmental protection are achieved in animal care facilities where potentially toxic chemicals are used by carefully developing and implementing a proactive administrative and engineering chemical containment program. The heart of the administrative program includes continuing employee training and education programs and clearly written procedures that exceed OSHA and EPA compliance expectations. Engineering-based containment strategies are then designed, developed, implemented, and assessed throughout the life of the study to provide maximum protection to te worker and work area without compromising either the wellbeing of the animal or the integrity of the experiment.

Figures

Why the Concern about Chemicals
in the Animal Care Facility?

Quantity of Materials Used
Animal Care Technicians are Primary “Users”
Educational Level and Training of Personnel
Biological Concerns of Animals

Chemical Containment in the
Animal Care Facility Requires
Careful Teamwork

Animal Care Unit Staff
Toxicology Group
Health and Safety Personnel
Engineering and Facility Staff
Waste Management Personnel

Chemical Containment Must Be
Maintained During All Phases
of the Experiment

Acclimation
Dosed Feed Preparation
Necropsy
Waste Operations

Containing Chemicals in the Animal Care
Facility Has Multiple Phases

Experimental Design and Protocol Development
Consultation with Health and Safety Personnel
Trial Procedures
Actual Experiment
Cleanup and Waste Removal