Laboratory and Healthcare Issues - Ventilation, Drug Exposures, Dust Control, Microbial Contamination, and Radiation


​Monday, May 23, 2016, 10:30 AM - 12:50 PM


Vortex Ventilation in the Laboratory Environment

L. Meisenzahl, Vortex Hoods, LLC, New Castle, USA Minor Outlying Islands

Objective: The objective is to improve safety by reducing exposure to contaminants by the users of ventilated enclosures including laboratory fume hoods. It is proposed that containment is enhanced in a hood that has a particular interior shape that causes a natural vortex to occur. The sustained vortex improves the efficiency of hood contaminant at low air flow.

Methods: The method used to test this hypothesis was the ASHRAE 110 tracer gas test. A known volume of tracer gas was emitted in the hood. A MIRAN SapphIRe infrared spectrometer was used to measure the concentration of tracer gas that escapes the enclosure. The design of the experiment included a written operating procedure, data collection plan and statistical analysis of the data. A chemical fume hood of traditional design was tested. The hood interior was then reconstructed to enhance the development of a vortex inside the enclosure. T​​​he hood was retested using the same method to compare the performance of the traditional interior shape with the enhanced vortex shape.

Results: The results are that in every aspect, the vortex hood showed significant improvement over the traditional hood design. Use of the Hood Index characterizing the dilution of gas in an air stream, as a logarithmic function, indicates a causal relationship between containment and volumetric air flow through an enclosure.

Conclusions: In conclusion the use of the vortex effect provides better protection for researchers using laboratory fume hoods. The use of air changes per minute, rather than face velocity, improves hood efficiency and reduces owner operating cost.



Hazardous Drug Handling and Contamination in Research Labs

T. Barton, St. Jude Children's Research Hospital, Memphis, TN

Situation/Problem: The same hazardous drugs that are the focus of safe handling guidelines in clinical care settings are also handled in research labs. Awareness about the safe handling guidelines in research labs is not comparable to what has become common in clinical care areas. The disparity in awareness and safe handling practices may result in potential exposure risk to lab researchers.

Resolution: Wipe samples were collected on various surfaces in several research labs where hazardous drugs are handled. A survey was administered to lab staff to assess how frequently they handle hazardous drugs, their handling practices, and use of PPE. Observations were made in laboratories to further evaluate common practices and compliance with PPE requirements.

Results: Hazardous drug contamination was found to be present on benchtops, lock boxes, and other surfaces in concentrations similar to what has been observed and published in several journal articles and NIOSH Hazard Alerts. The frequency with which researchers in these labs self-reported handling hazardous drugs was as high as or higher than the frequency reported of hazardous drug handling in clinical care areas. The use of engineering controls and PPE was not consistent with either institutional guidelines or safe handling guidelines.

Lessons learned: Although the NIOSH Alert promoting the Safe Handling of Hazardous Drugs in Health Care Settings was intended to be applied in research laboratories, researchers are often unaware of the term "hazardous drugs" or with applicable elements of safe handling guidelines. What is conventionally thought of as good chemical hygiene practices may not be sufficient when handling hazardous drugs whose health effects may include acute toxicity, carcinogenicity, and reproductive health effects. Efforts must be made to promote the overlooked elements of these safe handling guidelines and raise awareness of precautions that include the handling of closed chemical containers, the proper use of PPE, the use of engineering controls, and chemical decontamination of surfaces with a suitable agent (often bleach). Lab researchers must be aware of the potential for surface contamination with hazardous drugs and may need to rethink their application of regulatory requirements such as Designated Areas.



Hazardous Drug Exposure: Assessment and Hazard Communication

P. Lilley and J. Mancini, Army Public Health Center (Provisional), Aberdeen Proving Ground, MD

Situation/Problem: Anecdotal evidence suggested that pharmacies compounding and dispensing Hazardous Drugs (HD) may have a problem with lingering surface contamination by these same HD. An assessment was initiated to understand the extent of exposures in various sized pharmacies. Six common potential exposure contaminants were selected from the NIOSH list of HD.

Resolution: A two phase study was conducted, assessing the extent of HD surface contamination and evaluating a sampling model developed by the Army Public Health Center (Provisional) (APHC (Prov.)) During the first phase of the study, five representative Military Treatment Facility (MTF) Pharmacies were assessed to determine the scope of contamination across the Army. The pharmacies ranged in size from prescribing all of the target drugs multiple times daily, to prescribing only one of the target drugs annually. Each pharmacy was supplied with a commercial sampling kit, to take two samples. Simultaneously, with the first phase of the study, the APHC (Prov.) laboratory developed and validated an in-house analytical method to analyze 100 square centimeter wipe samples for the six HDs of interest. The second phase of the study commenced with extensive sampling at eleven Army MTFs pharmacies, including two pharmacies that participated in the first phase.

Results: Assessment of the sample results indicated an extensive surface contamination problem. Results showed that fourteen of the fifteen MTFs sampled had HD contamination in at least one sampling location at least ten times the limit of quantitation of the laboratory analytical method. One of the sites that participated in both phases enacted a major upgrade to their cleaning procedures between phases, resulting in a dramatic reduction in contamination from the initial assessment.

Lessons learned: Hazardous drug contamination occurred in nearly every pharmacy in the study. A lack of understanding about both the HD contamination and the potential exposure risk combined for an air of complacency among the workers handling and compounding HD. The presence of a HD specific cleaning protocol in a pharmacy does not guarantee that it is followed or effective. Improved hazard communication and training on cleaning procedures are necessary to implement and effective program that will reduce residual HD contamination.



Protecting Nurses from Antineoplastic Drug Exposures

T. Smith, Indiana University School of Public Health - Bloomington, Bloomington, IN; H. Woldu and D. DeJoy, University of Georgia, Athens, GA; A. Dyal, Kennesaw State University, Marrietta, GA

Objective: The objective of this study was to assess the impact of work and organizational factors, including safety climate, on the use of safe work practices to reduce nurses' exposures to antineoplastic drugs.

Methods: Data, to include only nurses from various work settings (n=1915), from the web-based NIOSH Health and Safety Practices Survey of Healthcare Workers were analyzed. Following preliminary analyses, two multiple linear regression analyses were completed to examine safe work practice outcomes including the use of engineering controls and personal protective equipment (PPE).

Results: For the first model, where PPE usage was the dependent variable, safety climate and familiarity with guidelines were the strongest positive predictors of use (p <0.0001). Nonprofit status, hospital setting, and having more employees were also relatively strong predictors of improved compliance (p=.002 to .006). Having additional precautionary measures (i.e. spill kits) was also related to improved compliance (p=.03). Number of treatments administered (p=0.00) and not being trained in the past 12 months (p=.008) were negative predictors of PPE utilization. In our second model, relevant policies/procedures, safety climate, and familiarity with guidelines were the strongest positive predictors for engineering control utilization (p <0.0001). Engineering control usage was also better for those who work for non-profit (p=.001) and government organizations (p=.007). Working in a hospital (p=.01) and the availability of precautionary measures (p=.05) also had a positive impact on engineering control practices, while usage was less for those who never received training (p=.002).

Conclusions: The findings of this study illustrate how organizational factors and safety management practices enhance safe work practices that will protect nurses from antineoplastic exposures. Familiarity with guidelines and a positive safety climate predicted both PPE use and engineering control use. Conversely, training deficiencies diminished the effective use of safe work practices. Interestingly, nurses working in nonprofit organizations exhibited the greatest safe work practices. Ultimately, the integration of a formal safety management system (such as AIHA/ANSI Z10) may prove beneficial in enhancing safety climate and improving nurses’ safe work practices.



Compliance with ICRA Dust Control in a Hospital

R. Beall, Entek Consulting Group, Inc., Rocklin, CA

Situation/Problem: This presentation will address practical application for compliance with the Infection Control Risk Assessment (ICRA) permit process to address the situation/problem of dust control on construction projects inside hospitals.

Resolution: Resolution to these challenges will include four examples of compliance for dust control that include: use of a mini-enclosure, two examples of larger containments, and one containment of dry-out of a wet ceiling in an operating room using the dehumidification machine to create the negative pressure. One of the larger containments will demonstrate a nontraditional approach to create the required negative pressure work containment by thinking outside the box. Finally, a discussion on the use of particle testing inside of the containment compared to outside of the containment. We will demonstrate how measurement of particles of different sizes can provide a valuable metric to the completion of the construction work before allowing the contractor to remove the containment barriers.

Results: Dust control in a sensitive work environment such as a hospital can be achieved by different approaches to obtain negative pressure. Negative pressure can be created within mini enclosures, larger containments using the traditional negative air units and within a small enclosure using a dehumidifier.

Lessons learned: Lessons learned from this presentation will be to realize there are different approaches to meet the intent of the ICRA requirements with the knowledge and experience of industrial hygienists to assist in presenting options. In addition, particle testing can be a valuable tool to assist Infection Control and the construction team and hospital staff to assure control of the construction area.



Evaluation of Microbial Surface and Air Contamination Using Active UV-C Technology in a Healthcare Setting

L. Lee, American Green Technology, South Bend, IN

Situation/Problem: UV-C technology has been used as a disinfection method for decades in the healthcare industry. The UV-C wavelength of 253.7 nanometers has been proven to be effective at eliminating or neutralizing dangerous pathogens like C. difficile, Methicillin resistant Staphylococcus aureus and more. The challenge with UV-C technology has always been the method of delivery. It can’t be used in an occupied spaces and is only effective on areas that are in its direct line of sight. The current technologies focus on cleaning surfaces to reduce healthcare associated infections. This study was designed to look at the relationship of surface and air contamination compared to the control and challenge areas for total bacteria counts in colony forming units.

Resolution: A study was conducted at an acute care hospital to evaluate the levels of both air and surface contamination using an active UV-C system, which utilizes a set of fans to draw air into the ceiling grid where a completely shielded UV-C chamber is hidden from view, operating 24/7. Air is pushed through the chamber, pathogens are neutralized and then disinfected air is pushed back out into the room. This system can operate in an occupied space.

Results: Before and after air and surface samples from the study showed that installation of the active UV-C systems reduced total bacteria count. The study reported the results of total bacteria per cubic meter of air in terms of raw cfu data and correction hole factor. The surface data was reported as raw cfu counts per 25 cm2. Cleaning and disinfecting the air had a dramatic effect on the bacteria levels of the air and surface contamination.

Lessons learned: This study was critical to understanding the causal relationship between air and surface contamination. Reducing the bio load of pathogens in the air appears to have a direct effect on the amount of pathogens that collect on surfaces. Continued research is needed to develop the relationship between reduction of biological loading and its association with healthcare associated infections. Understanding this relationship can help engineer controls to improve the risk of healthcare associated infections by reducing exposures to patients, staff and visitors to dangerous pathogens.



Serious Questions About Radiation Measurements

R. Johnson, Radiation Safety Counseling Institute, Rockville, MD

Situation/Problem: How often do we find ourselves interpreting data based on someone else’s radiation measurements without really knowing if the data are valid? Defensible decisions for radiation safety should begin with good radiation measurements. Unfortunately, many safety decisions are based on measurements with uncertainties, which are either unknown or neglected. Once a measurement is written down, it seems to take on a life of its own and all uncertainties are lost. We may not ask questions to verify the data, especially if the number is above an action level. However, before measurements are interpreted, they are just numbers. Once interpreted the numbers mean whatever people believe, often related to their fears of radiation. There are numerous errors which can result in measurements that do not represent the real world.

Resolution: Before making expensive decisions for radiation safety people need to understand that radiation is a random phenomenon. Even with great care, radiation measurements are only best estimates from a random distribution. When uncertainties are reported for measurements, in most cases they only account for the randomness of radiation. Ideally, they would include uncertainties due to calibration, energy response, and numerous operator judgment factors (geometry, location of measurement, speed of probe movement, etc.). Measurements should not be made in contact with a source without taking into account the location of potentially exposed people and occupancy time. Measurements made for gamma ray exposure should, also, consider a possible beta component. Also, care needs to be taken when reading the scale multiplier.

Results: Many expensive decisions for radiation safety may be avoided by careful evaluation of the quality of radiation measurements. However, because of fears of consequences, people may want to quickly implement radiation safety decisions without confirming the initial measurements. We will review several case studies where protective actions were implemented based on erroneous measurements that would not justify the safety decisions.

Lessons learned: The golden rule for measurements should be to repeat the sample and measurement for confirmation, ideally with different people and instruments, before making an expensive decision. By asking serious questions about radiation measurements, IHs may avoid making expensive decisions that are not warranted by poor quality radiation measurements.​