A History of the American Biological Safety Association
Part II: Safety Conferences 1966-1977
Richard H. Kruse and Manuel S. Barbeito
MEDI, Inc., Lexington, Kentucky
USDA (Retired), Frederick, Maryland
The first decade of biological safety conferences (Barbeito, 1997) were, to say the least, informal, congenial and informative, and started a precedent by which mutual safety problems were discussed and disseminated at one meeting.
From the beginning in 1955, with personnel from only three U.S. Army Chemical Corps installations in attendance, the conference had grown, by 1966, beyond all expectations and included universities, private laboratories, hospitals, industrial complexes and 17 government installations. The conferences now had presentations no longer bound by security. Attendees spanned the country from Maine to California. The past is not prologue; it is the foundation upon which great scientific disciplines are built. Many times data published in scientific journals were first presented at a safety conference. We listened, we learned, we taught, and we discussed mutual problems with old and newfound friends.
We could not summarize every presentation at each biological safety conference, but selected presentations we believed would interest the reader, or that described new equipment, a challenging hypothesis or new procedures: i.e., paraformaidehyde, new models and specifications for Class II biosafety cabinets, various methods of disinfection, design criteria and air sampling.
11th Biological Safety Conference
The 11th Biological Safety Conference was held on August 16-18, 1966 at Fort Detrick. It was apropos that the proposed universal biohazard warning symbol was displayed at Fort Detrick for the first time. Previously, a 6 in. round brown circle with infected agents printed around the circumference had been used at the three U.S. Army Chemical Corps installations. Charles Baldwin, Dow Chemical, described the inception of the biohazard symbol as follows: An international search for copyrighted, licensed, or registered symbols that were the same or similar was made. From various proposed symbols, a professional opinion group selected the symbol they deemed unique and with easily recognized distinctive colors.
J. Knowles, Pine Bluff Arsenal (PBA), discussed problems with liquid waste containing large quantities of quaternary ammonium compounds (QAC). When filtered through a membrane filter, microbial growth was inhibited, but adding 1% Darvan or Tamol N to the liquid waste prevented the inhibitory effect of QAC.
Dr. Charles Beard, USDA Southeast Poultry Research Laboratory, compared ocular, nasal, aerosol, and intramuscular (im) inoculations of GB strain of Newcastle Disease virus (NDV) in chickens and found hemaglutination inhibition titer highest via aerosol route and lowest via im route. Joseph Songer, National Animal Disease Laboratory, encountered cross-contamination with hog cholera virus even in adjacent and distant animal rooms due to lack of directional airflow. Cross-contamination was higher when relative humidity was elevated.
Several papers were presented by Fort Detrick personnel. J. Bruce Harstad evaluated HEPA filters with submicron T-1 bacteriophage and found penetration averaged 3 x 10-3. Charles Glick showed that various materials, from cotton to vermiculite, did not absorb the fluid when a bottle broke and the outer container leaked. Triple packaging with new methods and materials evolved that withstood drop tests from the seventh floor of the Pilot Plant onto a concrete pad. Theron Green infected Macaca mulatta parenterally with Venezuelan equine encephalitis (VEE), Rift Valley fever virus (RVF) and Rickettsia rickettsii (RMSF). The animals were restrained in primate chairs and continuous 24 hour specimens of urine and feces were collected and assayed for virus and rickettsia in mice and guinea pigs. VEE was excreted in the feces but not the urine; RVF was excreted in urine and feces; but RMSF was not excreted in either urine or feces.
Robert Hoffman evaluated decontamination with betapropiolactone (BPL) and recommended increasing space decontaminated per gal BPL from 16,000 to 25,000 ft3. Gardner Gremillion described the new laboratory research facility of the U.S. Army Medical Unit. Kenneth Hindman presented data on the explosive characteristics of dried microorganisms.
Everett Hanel described and reviewed two volumes of “Design Criteria for Microbiological Facilities at Fort Detrick.” These criteria, developed from a list for standardization of laboratory equipment and furniture, were revised and now encompass biological safety for the architect, engineer, manager, and scientist planning an infectious disease laboratory.
Dr. Wedum discussed the revised edition of “Assessment of Risk of Human Infection in the Microbiological Laboratory” in which he provided four “indicators of risk” to serve as guidelines for the safe handling of microorganisms. The first indicator was “number of laboratory infections.” The second indicator was “infectious human dose.” A working assumption was that the minimal human and animal infective doses were approximately the same. The third indicator was “infection of uninoculated control animals caged with or near inoculated cagemates.” The fourth indicator was “presence of microorganisms in urine and/or feces of inoculated animal.” In the published edition (Wedum, 1969), tabular summaries list 530 references and assumptions pertinent for 130 organisms or diseases.
A film “Laboratory Design for Microbiology,” funded by NCI and produced by CDC, was shown for the first time. The script written by Dr. G. Briggs Phillips and Derwood Thayer, CDC Audiovisual Facility, with the technical assistance of Mark Chatigny, was based on the assumption that biological safety designs and containment principles in virus research were synonymous to infectious disease laboratories. The film should interest scientists, engineers, and managers concerned with the design of biological laboratories or remodeling old facilities.
One of us (M.S.B.) described how three colleagues and he grew beards to challenge the hypothesis that bearded men pose more problems than clean-shaven men in microbiological laboratories. The beards were contaminated by aerosolization of non-infectious microorganisms. After exposure, the number of organisms retained in the beards was quantified. Data from unwashed, washed and sheared beards, and clean-shaven individuals showed recovery of microorganisms was significantly higher on bearded men than clean-shaven men. An additional experiment, performed in the modular Class III biosafety cabinet, used a mannequin’s head fitted with a beard of human hair. After exposure to an aerosol of GB strain of NDV, six-week old chicks were briefly nestled against the exposed beard and placed, in animal cages to assess the probability of cross contamination. Hemagglutination inhibition titers demonstrated that cross contamination did occur even when the contact exposure time was brief.
Dr. William Miller conducted a tour of Building 376. The building originally was constructed for aerobiological research with modified Reynier’s Chambers. In 1963, the building was “gutted” and safety cabinets were replaced with Class III biosafety cabinets, many in a modular system. Several toroidal rotating drums were installed with a pneumatic tube system to transport exposed animals to the animal rooms. Unique systems were installed to study the effects of natural and artificial sunlight on microbial aerosols. A large-volume air incinerator sterilized the air before discharge to the environment.
12th Biological Safety Conference
The 12th Biological Safety Conference was held on April 16-18, 1968 at the USPHS National Center for Urban and Industrial Health (NCUIH), Cincinnati, Ohio. Dr. Jerome Svore, Director of NCUIH, described the work and organization of the five branches of NCUIH: solid waste disposal, occupational health, injury control, and sea resources. Research also was conducted on noise levels, air pollution, seat belts, and flammable fabrics. Frederick Winkler discussed Executive Order 11282 that over a five-year period could cost 100+ million dollars to control air pollution from federal facilities. David Armstrong described qualitative and quantitative studies on microbial flora of the dust inside four municipal refuse incinerators. Areas sampled were the dumping area, charging floor, and residue area. The highest concentration of microorganisms recovered by an Andersen Sampler was from the dumping area and charging floor. Many fungi were recovered, as were pathogens of respiratory and intestinal tract origin.
A. Sarshad, Naval Biological Laboratories, described the old and new systems for thermal decontamination of air contaminated with Franciscella tularensis, Yersina pestis, Coccidioides immitis, and arboviruses. The old system, with a Nash Hytor vacuum pump and gas burner, had been used 10 years, and was replaced with an incinerator operated under 10 in. mercury vacuum. The incinerator could process 1,000 cfm of contaminated air retained at least 2 sec. at 600°F. For increased efficiency, the unit was fitted with internal deflectors.
One of us (M.S.B.) described tests on two semi-portable, large-volume incinerators, each with a capacity of 1,000 to 2,200 cfm air, used to sterilize pathogenic aerosols from a microbiological laboratory. Aerosols of liquid and dry suspensions of Bacillus subtilis subsp. niger (BG) spores and Serratia marcescens (SM) disseminated into the two incinerators showed SM required 525°F and BG spores 525-725°F at 1 sec. retention time for sterilization.
Robert Runkle, Becton, Dickinson and Company (B-D), described a portable HEPA-filtered, airflow animal cage rack that eliminated cage filter caps. Adjustable shelving was attached to an air distribution plenum that provided filtered laminar airflow across and around the animal cages.
Charles Baldwin described a mobile laboratory constructed on a semi-trailer truck chassis to: (1) meet mobility roadability requirements; (2) be self-sufficient for operation at site; (3) use conventional laboratory and animal facilities; and (4) provide containment of microbial organisms. The unit was sent to CDC and used for isolation of an etiologic agent.
From Fort Detrick, Ellen Kukla presented the history of biosafety cabinets from Class I to Class III. A prototype downward laminar flow biosafety cabinet, fabricated by the Baker Company, was sent to Safety Division for evaluation. Extensive modifications were required before the cabinet could pass stringent microbiological tests. The downward airflow offered product protection which was not possible in the Class I biosafety cabinet. Eventually this prototype biosafety cabinet was designated Class II. Charles Glick presented a history of ventilated suits. In 1944, ventilated suits were first used at Camp Detrick, but the suits were sent to the Manhattan Project. Later a plastic termed “cocoon” was sprayed on clothing to make it impervious with little success. A one-piece suit fabricated of laminated plastic with two zippers was obtained. Many improvements were made that culminated in a one-piece, one-zippered suit with increased air capacity, telecommunications, and a dehumidification system.
Larry Taylor reported on the use of depolymerized paraformaldehyde for space sterilization. Tests on ventilated biosafety cabinets, fiber glass filters, laboratories, and other area contaminated with SM or BG demonstrated the efficacy with ideal conditions of 3 mg paraformaldehyde per ft3 at 74°F, 68% relative humidity, and 1-hour contact time.
One of us (R.H.K.) in an earlier study (Kruse et al., 1967) differentiated between cross-infection and cross-contamination. To reiterate, cross-infection occurs when a cagemate becomes ill from microorganisms in urine, feces, saliva, or droplets from a diseased animal; and cross-contamination, when cagemates are infected by organisms released from the fur or skin before the exposed animal becomes ill. A series of experiments with GB strain of NDV demonstrated cross-infection spread, not only to controls in the same cage, but to controls in adjacent cages and to controls in cages located across the room. The methods of preventing cross-infection with NDV, by the use of ultraviolet irradiation and filter tops on cages, and application of these methods to mice and guinea pigs were described.
Dr. Wedum presented the history of shipping etiologic agents. USPHS 43 CFR 72.25, governing shipment of etiologic agents, was revised for containers of more than 500 ml (previously 1 gal.). Triple packaging was required to prevent leakage outside the outermost shipping container following impact of the container onto a 30 in. concrete slab. Drop tests from a helicopter at 1,000 ft at Edgewood Arsenal, Maryland, and the airplane crash tests in Arizona were discussed.
One of us (M.S.B.) described containment of microbial aerosols in a Class I biosafety cabinet. Data showed escape of organisms from the biosafety cabinet was dependent upon: (1) the number of organisms aerosolized in the cabinet; (2) activity in the room, namely movement of individuals; (3) opening and closing doors; and (4) decreased inflow air velocity. It was ascertained that a minimum of 75 fpm inflow velocity was necessary to entrap organisms aerosolized in the cabinet.
W. Emmett Barkley discussed the role of NCI’s Biohazard Control and Containment Committee. An information center was set up to compile and disseminate data on control and containment with areas of interest in laboratory infections, cross infections, containment, laboratory design, microbiological barriers (cabinets, etc.), and space decontamination.
13th Biological Safety Conference
The 13th Biological Safety Conference was held on October 14-16, 1969 at the U.S. School of Aerospace Medicine, Brooks Air Force Base, Texas.
A very interesting tour of the School of Aerospace Medicine conducted by Dr. Jerome Schmidt showed activities of the school. The human centrifuge fascinated most individuals. The participation with the space program was a learning experience, especially the cooperation that existed in America with other space agencies.
Formaldehyde was a main topic. Walter Ellis, Brown and Root-Northrop, Houston, described tests performed on equipment in Class III biosafety cabinetry. Parameters were manipulated to determine contact times and conditions. All equipment, filters, spaces, and surfaces in the Lunar Receiving Laboratory could be sterilized. Donald Braymen, NADL, described a simple titration method for assaying formaldehyde in air, and discussed factors such as relative humidity that affected sterilization efficacy.
Dr. Charles Beard described how filtered air in animal holding areas prevented cross infection with NDV. He emphasized that positive pressure was instrumental in producing poultry flocks free of disease. Donald Braymen described the aerosols created when soiled surfaces are cleaned with a high pressure spray. He further determined the size and number of airborne particles. Joseph Songer reviewed decontamination mats and their effectiveness in preventing the spread of infectious agents by footwear.
Ronald Akers, Dow Chemical, evaluated a laminar airflow biological safety cabinet, and found the laminar flow cabinet to be superior to the Class I biosafety cabinet. Several undesirable characteristics were modified and new configurations improved agent containment and product protection.
One of us (R.H.K.) described liquid and gaseous disinfectants for laboratory surfaces contaminated with RVF: asphalt tile, glass, rubber, painted and unpainted wood, paper, and plastic, contaminated with RVF. Concentration of the disinfectant, contact time, and the nature of the test material determined the effectiveness of the disinfectant. Thermal disinfection was evaluated by mixing the virus with animal bedding or excreta, and determining exposure time and temperature required for sterilization.
Dr. Robert McKinney, U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID), described basic approaches, production problems, and data from human trials for the development of vaccines for “at risk” laboratory personnel.
14th Biological Safety Conference
The 14th Biological Safety Conference was held on April 13-15, 1971 at the Centers for Disease Control, Atlanta. Several papers were presented by CDC personnel. Dr. George Mallison discussed the airborne spread of infection in hospitals where 4.7% to 15.5% of all patients were infected. The highest incidence of infection was from Escherichia coli, 26%; Proteus, 13%; Staphylococcus, 12%; Enterobacteria, 10%; and Pseudomonas, 9%. Sixteen percent of infections were respiratory. Dr. Kenneth Quist discussed problems handling monkeys. Tuberculin skin tests demonstrated a high incidence of tuberculosis. Ten percent of the imported monkeys were infected with Herpesvirus simiae (Monkey B). Other viral diseases were prevalent in monkey colonies. To protect personnel, the monkeys usually were quarantined for three months before distribution to various laboratories. Dr. John Richardson described the cooperation between USPHS and USDA to modify import permits. Dr. Bruce Dull recommended immunizations on a basis of risk as there were 25 vaccines available for laboratory personnel. It was noted how close the medical program duplicated Fort Detrick’s.
Dr. Wedum presented a brief history of etiologic agent packaging and current requirements for shipment of etiologic agents under development by the U.S. Department of Transportation. Dr. John Jeffries described Department of Agriculture’s regulations and policies governing importation and interstate movement of microbial agents and vectors. A vector was classified as any animal treated, inoculated, infected, or exposed to disease.
Fred Sabel, Dow Chemical, monitored barrier systems at NCI. In Building 41, the autoclaves were equipped with a pulse system that injected and evacuated steam three times. The filter was blown out because condensed water clogged the filter. He evaluated 47 biosafety cabinets from seven manufacturers and found 26 leaks around the filter frame and 13 through the filter. Joseph Songer described methodology used at NADL to sterilize rooms. Paraformaldehyde flakes (3 mg/L of space) were placed in a deep-fat fryer containing silicone fluid (SE-96, G.E. Company). Four to six hours were required to sterilize a room.
Dr. John Irwin described cabinets used at NIH. Horizontal airflow cabinets, known as clean work stations, were prohibited for use with viable microorganisms. Transfer by needle and syringe of potentially infectious fluids was forbidden. A downflow biological safety cabinet was used to work with infectious microorganisms. Norman Petersen, CDC-Phoenix, modified a Bioquest biological safety cabinet as a series of experiments showed a double-front window was required for containment of microbials. Albert Gates, NIH, illustrated with slides, difficulties sealing leaks in room penetrations of pipes, drains, electrical cables, etc. Concrete block walls painted with only one coat of epoxy had numerous leaks.
Everett Hanel discussed “Safety and Environmental Evaluation Program of NCI Contractor Laboratories.” The Office of Biohazards and Environmental Control, directed by Dr. Alfred Hellman, had two sections. Biohazards Research and Environmental Control headed by Emmett Barkley. This group refined and developed new environmental control equipment, devices, techniques, and assisted contractors on designs for building or remodeling, and selection of containment equipment. They made on-site visits to study and evaluate NCI contractor laboratories. Most workers in the viral oncology field believe they should not be exposed to viruses that can induce cancer in animals. Many employees believe the Class II biohazard cabinet to be too restrictive.
Back then, a big surprise…
The highlight of the conference was a plaque that read, “Presented to Dr. Arnold G. Wedum for Outstanding Contributions to Biological Safety By the 14th Biological Safety Conference, 1971.” Dr. Wedum treasured this plaque as it was given by his peers. Upon his return to Fort Detrick, the plaque was hung in a prominent place in his office.
15th Biological Safety Conference
The 15th Biological Safety Conference, sponsored by Environmental Services Branch, National Institutes of Health, and National Cancer Institute, was held on October 10-12, 1972 in Bethesda, Maryland. Dr. Alfred Hellman discussed recent developments in oncogenic research, and stated that work should be performed in a Class II biosafety cabinet for protection from potential biological hazards. Dr. Wedum described risk assessment parameters. Personnel should be aware that risks associated with microorganisms also could occur with carcinogens. A panel discussion featuring Drs. Lawrence Frenkel, NIH, Alfred Hellman, John Irwin, and Arnold Wedum followed. Each stated risk assessment was, and should be, a part of every scientific endeavor.
Donald Braymen used coliphage S-13 to assay virus liberated from an ultracentrifuge. Recovery of the virus on a slit sampler demonstrated the ability of the virus to withstand concentration and purification processes of the ultracentrifuge.Charles Baldwin discussed containment requirements for large-volume, zonal centrifuges.
In a session on biological safety training, Dr. Jean Martin, University of Washington, presented, “Psychology of Good Laboratory Practice,” Dr. Donald Vesley, University of Minnesota, described a course on “Principles of Biohazard and Injury Control for Biomedical Laboratories.” Charles Baldwin discussed a course on “Laminar Flow Biological Safety Cabinet Training.” Laboratory personnel should endeavor to eliminate behavioral and personal factors that may result in an accident. Bad relations between a supervisor and employee can create situations that may result in an accident. Each lesson learned may be instrumental in preventing an infection.
Stephen Pijar, USPHS, explained the importance of certifying biological safety equipment. Hazards such as pinhole leaks in HEPA filters may be missed because of faulty instrumentation. Leaks, in turn, could contaminate an experiment or cause an infection. Emmett Barkley described deficiencies and limitations of laminar flow biological safety equipment. Dr. Irwin reviewed biological hazards at NIH. Class I biosafety cabinets were being replaced with Class II biosafety cabinets that would be certified annually.
Safety in biomedical research was discussed by the following: (1) Dr. Garrett Keefer, NCI, “Implementation and Impact of Biological Safety and Environmental Control Standards in Virus Cancer Research”; (2) John Leach, NIH, “Potential Impact of OSHA on Biomedical Research Institutions”; and (3) Dr. Robert Huffaker, CDC, “Safety Standards for Employees in the Biologics Industry.” Personnel cognizant of the requirements for maintaining cultures know if the Class II biohazard cabinet is not used correctly, contamination of cells by bacteria, fungi, or PPLO can occur. This demonstrated that education, training, and use of approved techniques are essential for a successful safety program. A panel discussion on “Application of Safety Standards” ensued with Drs. Leon Jacobs, NIH, John Hyde, USDA, and Robert Kissling, CDC. Each indicated increased safety awareness by personnel is a must, and safety rules should be enforced.
Participating in a session on “Theory, Selection, and Application of Chemical Disinfectants” were Dr. V. W. Greene, University of Minnesota, “Disinfection and Sterilization Principles”; Dr. M.S. Korczynski, B-D, “Theory, Selection, and Application of Disinfectants in the Liquid and Aerosol Form”; Dr. Robert Huffaker, CDC, “Prototype Chemical Digester for Pathological Wastes”; Thomas Wilkinson, NIH, “Industrial Hygiene Aspects in Selection and Use of Chemical Disinfectants”; Dr. Edward Lazear, PBA, “Safe Destruction of Toxic Materials”; and A. Barton, Plum Island Animal Disease Laboratory (PIADL), “Sterilization of Sewage by Batch Cooking.” Presenters described methods for decontaminating microbial agents by various chemical disinfectants and processes. Several old processes have been modified to conform to new techniques and standards.
The concluding session was devoted to waste disposal with presentations by Vinson Oviatt, NIH, “Responsibility to the Community”; Joseph Corliss, FECA, “Regulations and Elements to Consider in the Preparation of an Impact Statement”; Dr. Edward Lazear, “Testing Facilities and Equipment for Destruction of Toxic Materials” and Robert Runkle, “Solid Waste Management of Disposable Medical Products.” The message from the participants was waste management still is a subject that must be clarified and solved. EPA and NIOSH have set guidelines. The regulations must be met so an impact statement can be prepared and instituted.
16th Biological Safety Conference
The 16th Biological Safety Conference was held on October 16-18, 1973 at the National Animal Disease Laboratory, Ames, Iowa. James Johnson, U.S. Department of Health, Education, and Welfare, discussed the impact OSHA has had on areas of employment. Of seven categories in the standard, six may apply to the laboratory. Vernon Rose described two viewpoints of OSHA. Some view it as the most important social legislation since social security, or Our Savior Has Arrived; whereas others term it the most unconstitutional freedom-interfering repressive legislation since prohibition. During the past two years OSHA conducted 67,000 inspections. The entire program was reevaluated to establish priorities and center on more comprehensive occupational health standards. Thomas Wilkinson discussed regulations and laws implemented on exposure and discharge limits of chemical and physical agents in biomedical facilities. Dr. John Richardson described USPHS’s revised requirements for interstate shipment of etiologic agents based on the “degree of hazard.”
On of us (M.S.B.) with NDV evaluated an air-filtered, portable, modular animal containment cubicle system for individual caging of animals that eliminates filtering the incoming and exhaust air and ultraviolet lights. Dr. Gerald McGarrity, Institute for Medical Research, demonstrated there was no airborne infection by Reo-3 virus in mice housed four weeks in the “cubicle system,” whereas 42% of mice housed in the same laboratory developed hemagglutination inhibition antibodies to the virus. The “cubicle system” significantly reduced airborne transmission of polyoma infection in mice.
Stephen Pijar reported difficulties encountered by NIH when purchasing laminar airflow biosafety cabinets. This provided an impetus for the development in May 1973 of Specification NIH-03-112 that became the official Specification for NIH’s laminar airflow biological safety cabinets in August 1973. Dr. Emmett Barkley described a newly designed Class II biosafety cabinet based on three parameters: downflow velocity, inflow velocity, and height of the work access opening that could be regulated by a sliding sash. Inflow of 100 fpm and downflow of 50 fpm provided excellent biological containment. This research was very significant. It was conducted in partial fulfillment of the requirements for Emmett’s PhD The microbiological tests were changed to add a metal cylinder simulating a worker’s arm on the work surface. The nomenclature for the cabinet became “Class II, Type B biohazard safety cabinet.”
Pamela Errico, Dow Chemical, described two slide-cassette training packages: “Effective Use of the Laminar Flow Biological Safety Cabinet,” and “Formaldehyde Decontamination of Laminar Flow Biological Safety Cabinets.” Dr. Lillian Schwenk, Iowa State University, stated increased technological complexity, with stringent safety requirements, have created additional problems for supervisors and employees. Traditional approaches have not been effective. Ideal solutions were thought to be self-enforcement, helping individuals to know themselves, and teaching them to assess the hazards. Dr. John Richardson reported a retrospective study showed over 100 laboratory-acquired infections have occurred from 1947-1973 at CDC.
Donald Braymen evaluated the effectiveness of footbaths in hospitals and laboratories. Under in-use conditions, even systems meticulously maintained, may spread microorganisms throughout the area. He concluded most footbaths were not effective.
John Blackwell, PIADL, evaluated disinfectants of alkali, organic acid, halogenated, QAC, and phenolic ring-containing structure for virucidal effect against exotic NDV. He concluded that all disinfectants, except QAC, inactivated virus to a level of at least 10-7 in 30 min. at 25-28°C.
Dr. James Sullivan chaired a session entitled, “To Organize or Not to Organize
17th Biological Safety Conference
The 17th Biological Safety Conference, sponsored by Becton, Dickinson and Company Research Center, was held on October 15-17, 1974 at the Velvet Cloak Inn, Raleigh, North Carolina. This was the first conference not at a government installation, and the first to be sponsored by industry. Opening night at poolside, there was an informal social hour with liquid refreshments and hors d’oeuvres, compliments of B-D.
Presentations ranged from asepsis in dentistry, by Dr. James Crawford, University of North Carolina (UNC), to experiments with exotic animal viruses, by John Blackwell. Dr. Wedum presented 13 bases for assessment of risk in viral oncology. Most notable were: (1) a positive serological change indicating there should be a revision of laboratory procedures; (2) immunosuppression absence in low-risk viruses; (3) cancer-inducing doses of laboratory material; (4) equipment and procedural hazards, i.e., the hypodermic syringe and needle are the most dangerous; (5) excretion in urine, feces, and sputum; (6) cross infection of caged animals; (7) induction of cancer in subhuman primates but not in rodents; and (8) viral-induced permanent transformation of human cells in vitro. He concluded that experimental procedures present more risk to the experiment than to the health of the experimenter.
Charles Glick described packaging prescribed by USPHS and Department of Transportation for shipment of etiologic agents. The differences between packages containing 50 ml and those with less were described, with numerous precautions noted. A primary container with surrounding absorbent material was placed in a second durable, watertight container surrounded by more shock-absorbent materials, and then enclosed within a shipping container of corrugate fiberboard, cardboard, wood, or another material of equivalent strength.
Safety programs and training were discussed and evaluated. In “Safety Management in the Public Health Laboratory,” Dr. John Forney, CDC, discussed glaring examples of unsafe practices such as 5 gal. containers of acetone and other volatile chemicals, amounts far in excess of working requirements. He observed improper handling of contaminated materials, inadequate sterilization, insufficient ventilation, and eating and drinking in the laboratory. He recommended that one person should be responsible for the entire safety program. Dr. Emmett Barkley presented a cancer research policy. Dr. Donald Vesley stated a follow-up evaluation should be an intrinsic part of any program. Pamela Errico discussed NCI’s research training program which began in 1972 at the University of Minnesota with a course on injury control and the principles of biological safety. Audiovisual training material was developed with slides and an explanatory recitation cassette.
Warren Powell, NIH, described the results of testing and servicing approximately 150 Class II laminar flow biosafety cabinets. Thomas Wilkinson described OSHA’s carcinogenic studies in research facilities, and how OSHA’s requirements create problems and challenges to personnel. Fred Sabel evaluated the potential hazards from a cell-washing centrifuge with T-3 coliphage and BG. The major hazard was direct contact by the operator during removal of centrifuge tubes. He was unable to completely decontaminate the centrifuge. John Blackwell showed that foot and mouth disease virus survived pasteurization at 72°C for 15 sec. Dr. John Irwin, by a series of tests, showed that acetone as a viricide was unnecessary. He further explained that 60% ethanol with 0,01 N HCI inactivated Staphylococcus aureus and E. coli, but BG spores were resistant. Dr. Gerard Spahn, FCRC, analyzed various commercial disinfectants and found ethanol and an iodine solution inactivated Rauscher Leukemia virus (RLV) within 10 sec.
Another first for B-D. The proceedings of the conference were compiled, printed, and presented to each attendee.
18th Biological Safety Conference
Another milestone in the history of the biological safety conference; for the first time a state was involved. The Department of Human Resources, Commonwealth of Kentucky, sponsored the 18th Biological Safety Conference held on October 15-17, 1975 at the Campbell House Inn, Lexington.
Originally, a Vice President of the University of Kentucky was involved, but he left because of the untimely death of his wife. Dr. H. “Mac” Vandiviere, Director, Remedial Services, came to the rescue, and with the assistance of many friends, the plans for the conference went forward. Following B-D, what could be done to have a conference that would be as informative and enjoyable? Would that have had noted presenters and excellent presentations and have copied a few of B-D’s gratuities? Sunday night, at poolside, liquid refreshments and hors d’oeuvres were served, compliments of Germfree Laboratories. Luncheons were made possible through donations from pharmaceutical industries. One further note, Captain Boris Osheroff, USPHS, had invited several students enrolled in the Environmental Health Program at Indiana State to the conference. Pharmaceutical industries paid for all their meals including the banquet.
Dr. Ernest Chick, Respiratory Disease Hospital, discussed the mycology program in Kentucky, from isolation of the causative fungus from an individual, to confinement in the hospital for 16 weeks treatment with amphotericin B, plus weekly immunological profiles with follow-up cultures and immunology after discharge. The patient recovery rate was excellent, with only one reoccurrence.
The next two speakers would make any safety conference informative and successful. Dr. Arnold Wedum presented the “History of Microbiological SafetyM. tuberculosis. From the slides that were shown, one could vividly see how cabinets and other developments in safety evolved from the “dark ages” to the present (Table 1).
Dr. Robert Pike, University of Texas Southwestern Medical School, related how Dr. S. E. Sulkin and he started recording data of laboratory-associated infections they obtained from questionnaires and personal communications. In “Summary and Analysis of 3,921 Laboratory-Associated Infections,” only 64% of the cases occurred in the United States and 164 were fatal. Only 18% of the infections were due to known accidents, 42% were caused by bacteria, and 27% by viruses. Research activity accounted for 59%. Table 2 illustrates the number of infections in 10-year increments.
Back then, another surprise…
Dr. Michael Furcolow surprised Dr. Wedum by inducting his old friend into the Order of Honorary Kentucky Colonels. Dr. Wedum was proud of this because of his affiliation with “military brass” throughout his career, and mentioned his induction in his Christmas letter.
Before lunch Dr. Wedum asked how we were able to get Dr. Pike? I, (R.H.K.), replied, “One telephone call and the fact that you two are synonymous with safety.” After lunch, featuring a Kentucky “hot brown,” Dr. William Worthington, a veterinarian from Lexington, described the thoroughbred industry with slides showing conception, palpation of the mare, birth of the foal, and training the horse. He closed his presentation with, “As the stallion said to the mare, it’s been a business doing pleasure with you.”
Dr. Sol Miller, Abbott Laboratories, described diagnostic procedures based on radio-immuno essay that combined sensitivity of radiochemistry with specificity of immunology. Joseph Songer discussed FAMULUS, a computer-based system for collecting and retrieving information on biohazards and related subjects. He accumulated over 3,500 reprints and references for the system. Dr. Gerard Spahn exposed RLV to ultraviolet irradiation and demonstrated that irradiation destroyed biological activity (infectivity) without affecting either functional or total protein assays.
Boris Osheroff chaired a panel discussing the National Environmental Policy Act (NEPA). From the panel: (1) Charles Custard, HEW, explained that laboratory accidents limited to personnel and animals were not affected by NEPA for they do not affect the environment; (2) Dr. Rudolf Wanner, NIH, described the utilization and expertise necessary for surveillance under a centralized environmental health and safety program; and (3) Dr. Johannes Stuart, CDC, described an accident on a commercial airplane involving a large spill of polio virus. Federal and private agencies have created confusion by independently developing requirements for transporting etiologic agents.
One of us (M.S.B.) chaired a panel discussion of laminar flow Class II biosafety cabinetry. From the panel: (1) Gary Sherlaw, National Sanitation Foundation (NSF), described methods used to formulate a standard, and discussed progress made on the standard for Class II biosafety cabinets; (2) Stephen Pijar explained certification methods; (3) Fred Sabel described tests that must be performed for a biosafety cabinet to meet NSF Standard Number 49; and (4) Warren Powell discussed problems at NIH that occurred when over 150 Class II biosafety cabinets were tested.
William Shirey, FCRC, described a method to recover energy from air exhausted from buildings requiring 100% fresh air. An energy recovery wheel involving an exchange of heat from the exhaust to the intake was installed in two buildings. There, the system was evaluated with an aerosol of T1 coliphage. The energy wheel recovered 70 to 90% of the energy, and had a release of organisms to the supply side of less than 0.1% determined by the biological tests.
19th Biological Safety Conference
The 19th Biological Safety Conference was held on October 18-20, 1976 at the Frederick Cancer Research Center. The conference was somewhat subdued because our mentor and friend Dr. Wedum, who died of cardiac failure on June 22, 1976, would no longer be at safety conferences. Through the years, all learned from Dr. Wedum, whether in answer to a question, conclusions after a presentation, or during conversations at coffee breaks and meals.
William Shirey described a containment laboratory designed for large-scale production of oncogenic viruses at the Frederick Cancer Research Center. David Weathers described CDC’s new containment laboratory for Class IV viruses. Although the facility was under construction, planned operating procedures were described with safety a major issue. Dr. Robert Huffaker took the attendees on a slide tour of New York State Health Laboratories emphasizing design, safety aspects, equipment, and support services. Norman Petersen described the facilities at CDC-Phoenix and the continuing hepatitis research with chimpanzees and marmosets. Leon ldoine, FCRC, described methods to develop slide-tape shows. John Blackwell assured everyone it was safe to remove film from hazardous areas in his presentation on the decontamination of 35 mm and movie film.
Monday night, at the dinner meeting at Cozy Restaurant, Thurmont, Maryland, Dr. Karl Johnson, CDC, described the scientific reality of hazardous pathogens. Truly amazing were public perceptions and anxieties of people when they learned research with infectious microbials was being conducted in their area.
Dr. Jerry Walker explained safety procedures and equipment such as air-tight animal rooms; air-sealed gasketed doors; and automatic washdown airlocks that have been used over 20 years at PIADC. Plum Island, and the USDA facility at Ames, Iowa, had been designated as Centers in 1975. Maxine Singer, NIH, discussed the widespread scientific and public concerns over safety of new agents derived from joining DNA fragments. Dr. Emmett Barkley described the “NIH Guidelines for Recombinant DNA Molecules,” and defined the four levels of physical containment contained therein. Joseph Songer upgraded the FAMULUS archive to over 4,000 reprints and 8,000 references.
Tuesday night, a social was held at the Red Horse Steak House at which time the mayor of Frederick, Ronald N. Young, described the criteria Frederick met to be selected as an all-American City. He extolled the conversion of the downtown area that now resembles the city as It was during the Civil War period. This has been described and published in leading magazines. A good time was had by all from company presidents, scientific personnel, and Mrs. Wedum.
Kenneth Schatzle explained the purpose of NSF and its participation in formulating a standard for laminar flow biosafety cabinets. The first standards preparation committee convened on January 23, 1973 in Ann Arbor, Michigan, with nine biosafety cabinet manufacturers participating. Three working task groups were formed, each charged with a particular phase of the standard. After numerous meetings where discussions were, to say the least, invigorating, a final draft of NSF Standard Number 49 was completed and adopted on June 11, 1976. Implementation and biosafety certification testing started November 1976.
The last session was an eulogy to Dr. Wedum with Mrs. Wedum in attendance. Drs. Robert Stevenson and William Payne described numerous awards Dr. Wedum received: in 1959, the Army Exceptional Civilian Service Decoration from the Secretary of the Army at a Pentagon ceremony; in 1961, the Department of the Army Certificate of Achievement; and in 1972 the Department of the Army Decoration for Meritorious Civilian Service. From his peers, Dr. Wedum received many accolades for his vast experience and knowledge of safety. Extremely brilliant and wise, an outstanding teacher whose contributions, fundamental principles, practices, and dedication to safety were far-reaching and always will be followed throughout the world. “Assessment of Risk of Human Infection in the Microbiological Laboratory” will never be forgotten. It was decided to have a lasting memorial to Dr. Wedum in the form of an annual memorial lecture at future biological safety conferences.
20th Biological Safety Conference
The 20th Biological Safety Conference, sponsored by Brooks Air Force Base, Texas, convened on October 12-14, 1977 at the Broadway Plaza Motor Hotel, San Antonio.
The advent of surgical procedures to replace human heart valves with swine aortic prostheses has increased, and led to the importation of swine hearts from foreign sources where exotic animal diseases are endemic. H. R. Cunliffe, PIADC, described procedures used to prepare glutaraldehyde-fixed swine hearts. Various combinations of concentrations and exposure times were evaluated for the inactivation of viruses of African swine fever, hog cholera, foot and mouth disease, and swine vesicular disease in heart valve tissue of experimentally infected swine. Swine heart valves fixed with glutaraldehyde may be used as xenographs in the human heart.
James Grantham, Certek, Inc., furnished additional data on an automatic formaldehyde generator he briefly described at the nineteenth biological safety conference. No longer were frying pans necessary, the Certek generator depolymerizes the paraformaldehyde. After a selected contact time, the formaldehyde gas is neutralized by ammonium carbonate, and filter changing or repair is now possible.
The safety conference became international with the attendance of Dr. Alfred Wallbank, University of Manitoba Medical College, and Dr. P. H. Trexler, Royal Veterinary College, London. Dr. Wallbank showed that Wescodyne was ineffective as a germicide when used for 80 min. against polio virus, thereby contradicting “Guidelines for Research Involving Recombinant DNA Molecules” that recommends 2% and 5% aqueous solutions for decontamination and spills. Dr. Trexler discussed flexible film isolators and their use to protect personnel and the environment from dangerous microorganisms.
Dr. Daniel Liberman, MIT, described environmental and personal monitoring of microorganisms that may be released from containment. There were three phases: environmental sampling, diagnostic microbiology, and molecular biology.
From FCRC, Orley Bourland discussed events leading up to the decision that the United States needed a P4 facility to continue research on high-risk microorganisms, and to provide a facility that would be available for outside investigators. Everett Hanel provided a history of the Class III modular biosafety cabinet that was designed by Fort Detrick’s Engineering Division and Safety Division, and fabricated and installed by the Blickman Company in 1954 in Building 550, Fort Detrick. From 1954 to 1971, many studies were performed with highly infectious microorganisms including H. simiae, C. immitis, M. tuberculosis, Coxiella burnetii, Y. pestis, B. anthracis, F. tularensis, RMSF, RVF, VEE, and botulinum toxin. Extensive modifications of the facility began in January 1977 to prepare it for recombinant DNA at the P4 level. Stephen Pijar discussed the tests performed on the P4 facility and described the problems encountered.
Dr. Robert Hackney, UNC, surveyed the Class II biosafety cabinets located on campus. Of 28 cabinets, only three had been tested and certified since initial installation five years previously. Sixty-four percent had leaks in downflow filters and 25% had leaking exhaust filters. Dr. Byron Tepper, The Johns Hopkins Medical Institutions, described various warning signs required at the institutions. The degree of hazard is placed on the warning placard and up to three levels of risk can be identified.
Barbara Rake, The Baker Company, evaluated the effect of cross-drafts on the containment of a biosafety cabinet meeting NIH specifications. Personnel and product microbiological tests showed that cross-drafts must be eliminated to circumvent microbial contamination exiting the biosafety cabinet.
After cocktails and dinner, Dr. Karl M. Johnson presented the 1st Arnold G. Wedum Memorial Lecture, “Andromeda’s Kitten: Class IV Viruses in the Modem World.” During dinner, one of us (R.H.K.) sat at the head table and observed Karl as he scribbled notes on a matchbook. From this paucity of notes, what a speech he delivered for it enthralled everyone. His description of episodes in the tropical savannah with poor living conditions, lack of safe drinking water, unsanitary conditions, and coping with the superstitious beliefs of the natives as he searched for the causative agent of Machupo and how it spread, illustrates what a dedicated individual will do in the interest of science.
Class III biosafety cabinets would be of little value in the tropical savannah. At a meeting, Dr. Wedum asked Robert Boyer of Safety Division to design and fabricate a plastic cabinet that Karl could use in South America that would provide some protection when negative pressure was provided by a gas-driven generator.
Then Karl described the case of an animal caretaker who died from Machupo; the progression of the disease and the regression of the patient were vividly explained. During the question and answer period, Karl discovered that the person sitting next to him (Chris Kruse) was one of the two nurses who attended the patient on Ward 200, a branch of Walter Reed Army Hospital, at Fort Detrick. Long and detailed conversations ensued between Chris and Karl.
It is impossible to tabulate the first year that participating organizations were represented at safety conferences because of increased attendance and paucity of data. More government agencies, colleges, universities, laboratories, and industries were involved. Table 3 was most difficult to prepare as many presentations at safety conferences were published without our knowledge and safety listings by our Canadian friends had not been inaugurated. We have attempted in Table 4 to list ABSA leaders who attended biological safety conferences during this decade of meetings.
This completes a brief history of the first 20 biological safety conferences. We hope the account has given at least a flavor of the wisdom, technical knowledge, and deep concern for others that characterized the remarkable career of Dr. Wedum. The American Biological Safety Association is a living, growing monument to his sagacity and vision. We can think of no other appropriate model for current and future members of this Association to look to for inspiration in the conduct of their profession.
Barbeito, M. S., & R. H. Kruse. 1997. A History of the American Biological Safety Association Part 1: The first 10 biological safety conferences 1955-1965. J. Am. Biol. Safety Assoc. 2:7-19.
Federal Register. 1976. Recombinant DNA research guidelines. Fed. Regist. 41:27902-27943.
Kruse, R. H., T. D. Green, & W. D. Leeder. 1967. Infection of control monkeys with Coccidioides immitis by caging with inoculated monkeys, p. 387-395. In L. Ajello, (Ed.). Coccidioidomycosis. University of Arizona Press, Tucson.
Meyer, K. F., & B. Eddie. 1941. Laboratory infections due to Brucella. J. Infect. Dis. 68:24-32.
National Sanitation Foundation. 1976. Class II (laminar flow) biohazard cabinetry. National Sanitation Foundation standard no. 49, National Sanitation Foundation, Ann Arbor, MI.
Phillips, G. B. 1961. Microbiological safety in U.S. and foreign laboratories. Fort Detrick, Frederick, MD. Technical study 35. AD 268-635. (National Technical Information Service, 5285 Port Royal Road, Springfield, VA 22151).
Phillips, G. B. 1965. Casual factors in microbiological laboratory accidents and infections. Fort Detrick, Frederick, MD. Misc. publ. 2. AD 615-012N. (National Technical Information Service, 5285 Port Royal Road, Springfield, VA 22151).
Pike, R. M. 1976. Laboratory-associated infections. Summary and analysis of 3,921 cases. Health Lab. Sci. 13:105-114.
Proceedings of the Conference on Airborne Infection 1961. Bacteriol. Rev. 25:173-382.
Stein, L., R. E. Anderson, & N. H. Gross. 1949. Potential infectious hazards of common bacteriological techniques. Bactedol. Proc., p. 10-11.
Sulkin, S. E., & R. M. Pike. 1951. Survey of laboratory-acquired infections. Am. J. Public Health 41:769-781.
U.S. Public Health Service. 1947. A laboratory building for study of highly infectious diseases. Engr. News-Record 139:460-463.
U.S. Public Health Service. 1980. Code of Federal Regulations Title 42, Part 72, Interstate shipment of etiologic agents. U.S. Government Printing Office, Washington, DC.
Wedum, A. G. 1953. Bacteriological safety. Am. J. Public Health 43:1428-1437.
Wedum, A. G., & R. H. Kruse. 1969. Assessment of risk of human infection in the microbiological laboratory, 2nd ed. Misc. publ. 2. Department of the Army, Fort Detrick, MD. (National Technical Information Service, 5285 Port Royal Road, Springfield, VA 22151).
Whitfield, W. J. 1962. A new approach to clean room design. Sandia Corp. technical report no. SC-4673 (RR). Sandia Corp., Albuquerque, NM.
Winslow, C. 1908. A new method of enumerating bacteria in air. Science 28:28-31.
|Landmarks in Microbiological Safety|
|Year||Person or Place||Event|
|1908||Winslow*||Microbial impingement air sampler.|
|1941||Meyer & Eddie*||Survey of 73 foreign and 74 U.S. Brucelia laboratory cases.|
|1947||NIH Building 7*||First peacetime research laboratory designed for microbial safety.|
|1949||Detrick-S Div.*||Investigation began on microbiological procedures.|
|1950||Sulkin & Pike*||Presented in St. Louis their nationwide survey of laboratory infections. Data published in 1951.|
|1950||Detrick-S Div.*||Class I Biological Safety exhibited at Society of Bacteriologists. Data published in 1953.|
|1954||Detrick-S Div. Building 550.||First and only building solely for microbial safety.|
|1954-56||U.S.D.A.||Plum Island Animal Disease Laboratory established|
|1955||Detrick||First Biological Safety Conference|
|1957||U.S.P.H.S.*||Regulation, Transportation of Etiologic Agents, (42 CFR 72.25).|
|1959-60||Phillips*||Visited and surveyed 111 U.S. and foreign laboratories.|
|1960||ASM*||First “Conference on Airborne Infection,” Miami Beach, Florida. Data published in 1961.|
|1962||Whitfield*||Advanced concept of unidirectional airflow.|
|1964||NCI||$1 million of $10 million for viral cancer given to start a Biohazard Safety Program.|
|1964||Phillips*||First and only PhD thesis on microbial and I laboratory safety awarded by New York University.|
|1969||Wedum & Kruse*||“Assessment of Risk of Human Infection in the Microbiological Laboratory” published.|
|1975||U.S.P.H.S.||President Ford signed new “Regulations and Transportation of Etiologic Agents.”|
|1976||NIH*||“Federal Guidelines for Recombinant DNA Research.”|
|1976||NSF*||National Sanitation Foundation Standard Number 49. “Class II (Laminar Flow) Biohazard Cabinetry.”|
|1976**||Frederick, MD||Death of Dr. Arnold G. Wedum.|
|Compiled by A. G. Wedum and R. H. Kruse.|
* Found in References
** Added to Table by R. H. Kruse
|Distribution by Decade of 3,921 Cases of Laboratory-Acquired Infections|
|Bacteria||175 (168)||311 (247)||440 (243)||528 (168)||155 (92)||60 (27)|
|Viruses||5 (5)||68 (65)||113 (101)||298 (180)||296 (202)||269 (187)|
|Rickettsiae||7 (7)||26 (17)||175 (112)||289 (203)||64 (7)||12 (8)|
|Fungi 8 (8)||8 (7)||25 (13)||112 (100)||110 (100)||90 (82)|
|Chiamydiae||0 (0)||38 (29)||26 (19)||46 (18)||15 (10)||3 (0)|
|Parasites||6 (6)||8 (3)||9 (3)||45 (19)||22 (18)||25 (19)|
|Unspecified||3 (3)||5 (3)||9 (0)||17 (0)||0 (0)||0 (0)|
|Total||207 (197)||464 (371)||797 (491)||1335 (688)||662 (430)||459 (323)|
|Parentheses indicate number published. (Pike 1975)|
|Selected Publications by Participants|
at the 10 Biological Safety Conferences
|Akers, R. L., R. J. Walker, F. L. Sabel, & J. J. McDade. 1969. Development of a laminar air-flow biological cabinet. Am. Ind. Hyg. Assoc. J. 30:177-185.|
|Baldwin, C. L., & R. S. Runkle. 1967. Biohazards symbol: development of a biological hazards warning signal. Science 158:264-265.|
|Baldwin, C. L., & P. H. Errico. 1975. Biological safety cabinets for contamination. J. Chem. Educ. 52:A545-A549.|
|Barbeito, M. S., & L. A. Taylor. 1968. Containment of microbial particles in a microbiological safety cabinet. Appl. Microbiol. 16:490-495.|
|Barbeito, M. S., C. T. Mathews, & L. A. Taylor. 1967. Microbiological laboratory hazard of bearded men. Appl. Microbiol. 15:899-906.|
|Barbeito, M. S., L. A. Taylor, & R. W. Seiders. 1968. Microbiological evaluation of a large-volume air incinerator. Appl. Microbiol. 16:490-495.|
|Barkley, W. E. 1972. Evaluation and development of controlled air flow systems for environmental safety. PhD thesis. University of Minnesota, Minneapolis.|
|Barkley, W. E. 1973. Facilities and equipment available for virus containment, p. 327-341, In A. Heilman, M.N. Oxman, and R. Pollack (ed.)., Biohazards in biological research. Cold Spring Harbor Laboratory, Cold Spring Harbor, NY.|
|Barkley, W. E., & A. G. Wedum. 1977. The hazard of infectious agents in microbiological laboratories, p. 740-753. In S. S. Block, (Ed.). Disinfection, sterilization, and preservation, 2nd ed. Lea & Febiger, Philadelphia.|
|Braymen, D. T., & J. R. Songer. 1973. Aerosol emmisions from the ultracentrifuge vacuum system, p. 79-85. In L. S. ldoine, (Ed.). Centrifuge biohazards: proceedings of the cancer research symposium 1973 November 8, Frederick Cancer Research Center, Frederick, MD. Contract no. N01-CC-25423, National Cancer Institute, Bethesda, MD.|
|Braymen, D. T., J. R. Songer, & J. F. Sullivan. 1974. Effectiveness of footwear decontamination methods for preventing the spread of infectious agents. Lab. Animal Sci. 24:888-894.|
|Crawford, J. J. 1977. Sterilization, disinfection, and asepsis in dentistry, p. 685-704. In S. S. Block, (Ed.). Sterilization, disinfection, and preservation, 2nd ed. Lea & Febiger, Philadelphia.|
|Dow Chemical U.S.A. 1974. A workshop for certification of biological safety cabinets. Contract with National Cancer Institute (contract no. BH74-01-011). Dow Chemical U.S.A., Midland, MI.|
|Glick, C. A., & A. G. Wedum. 1969. Leak tests by high-velocity impact of infectious specimen containers. Public Health Rep. 83:783-786.|
|Hanel, E., Jr., & R. H. Kruse. 1967. Laboratory-acquired mycoses. Fort Detrick, Frederick, MD. Misc. publ. 28. AD 665-376. (National Technical Information Service, 5285 Port Royal Road, Springfield, VA 22151).|
|Harstad, J. B., & M. E. Filler. 1969. Evaluation of air filters with submicron viral aerosols and bacterial aerosols. Am. Ind. Hyg. Assoc. J. 30:280-290.|
|Hoffman, R. K., L. M. Buchanan, & D. R. Spinner. 1966. Betapropiolactone vapor decontamination. Appl. Microbiol. 14:989-992.|
|Johnson, K. M., S. B. Halstead, & S. N. Cohen. 1967. Hemorrhagic fevers of Southeast Asia and South America: A comparative appraisal. Prog. Med. Virol. 9:105-158.|
|Kenny, M. T., & F. L. Sabel. 1968. Particle size distribution of Serratia marrescens aerosols created during common laboratory procedures and simulated laboratory accidents. Appl. Microbiol. 16:1146-1150.|
|Kruse, R. H., & A. G. Wedum. 1970. Cross infection with eighteen pathogens among caged laboratory animals. Lab. Anim. Care 20:541-560.|
|Kukla, H. E. 1971. Evaluation of a vertical airflow microbiological cabinet. J. Am. Assoc. Contam. Control 3:5-10.|
|National Cancer Institute. 1975. Certification of Class II (laminar flow) biological safety cabinets (42 slides, 15 min. cassette tape). National Institutes of Health, Bethesda, MD.|
|National Cancer Institute. 1975. Formaldehyde decontamination of laminar flow biological safety cabinets (42 slides, 13 min. cassette tape). National Institutes of Health, Bethesda, MD.|
|National Institutes of Health. 1974. Specification. Class II, type I safety cabinet. NIH-03-112c. National Institutes of Health, Bethesda, MD.|
|Sullivan, J. F., & J. R. Songer. 1966. Role of differential air pressure zones in the control of aerosols in a large animal isolation facility. Appl. Microbiol. 14:674-678.|
|Taylor, L. A., M. S. Barbeito, & G. G. Gremillion. 1969. Paraformaldehyde for surface sterilization and detoxification. Appl. Microbiol. 17:614-618.|
|U.S. Army. 1970. Design criteria for microbiological facilities at Fort Detrick, 2nd ed., vol. I and II, Revised by M. Dick, & E. Hanel, Jr., Department of the Army, Fort Detrick, MD. (National Technical Information Service, 5285 Port Royal Road, Springfield, VA 22151).|
|Wedum, A. G. 1974. Biohazard control. In E. C. Melby, Jr., and N. H. Akman, (Ed.). Handbook of laboratory science, Vol. I. Chemical Rubber Company Press, Inc., Cleveland, OH.|
|Wedum, A. G., W. E. Barkley, & A. Hellman. 1972. Handling of infectious agents. J. Am. Vet. Med. Assoc. 161:1557-1567.|
|ABSA Presidents Who Participated|
in One or More of the 10 Biological Safety Conferences
|ABSA President||Year President||Year First|