Protecting our Greatest Asset in the Lab – The Student
By: Michele Pollio, senior lab planner at SmithGroup
Whether for teaching, research, or processing, laboratories can be the most dangerous environment in any facility. This is true for labs utilized by sophisticated users, but even more so for labs dedicated to novice users– students. As we design labs, we consider many exciting aspects of the labs to shape a positive student experience - from accommodating pedagogy to designing attractive spaces, developing identity, and fostering a sense of community. The creation of safe spaces for learning is one of the most important considerations in lab design and one that students may never notice. Students are a vulnerable population who don’t have the benefit of a lifetime of learning good lab practices. Our first duty to them is to provide the safest space possible that will protect them – often without their knowledge or active participation in their safety. Our second job is to provide spaces that indoctrinate them into safe habits, potentially in preparation for a career in science.
There are many ways that the design of labs contributes to safety including the design and layout of the lab, the location and installation of equipment and furnishings in the lab, and the layout of the facility.
Spacing Between Benches. Locate back-to-back benches at least five feet apart to prevent students from bumping into each other as they walk by. For locations in front of fume hoods, the measurement should be taken from the face of the fume hood, not from the adjacent bench, as most fume hoods are deeper than benches. This is the place to add extra space since it is one of the most dangerous places in a lab.
Storage of Personal Items. Provide places for students to put their bookbags and coats. These items should not be located at their seats or on the floor, where they can be trip hazards. Food and drinks should never enter labs to avoid ingestion and to avoid the possibility of non-compliance with regulatory requirements. They can be excluded by providing places outside of the labs for students to put them. In addition to providing a place for the ubiquitous coffee cups, this serves as a sign that teaches students that food does not belong in a lab.
Egress. Provide two exits from labs, even when not required by code. If the configuration doesn’t allow an exit to the corridor, egress can pass through another lab or room of equal or lesser hazard. Never make emergency egress pass through a “danger zone,” such as in front of a fume hood or places where students are handling sharp instruments.
Fume Hood Location. Walking by fume hoods creates air movement that can disturb containment, so provide fume hoods in areas with limited traffic, such as the edges of rooms, in alcoves, or at the back of the lab, so that students don’t walk by them to get to their stations. Fume hoods should not be located near doors, across an aisle from other fume hoods, or near diffusers. Anything that can disrupt airflow near a fume hood should be considered. The same general rules apply to biosafety cabinets about avoiding locations that create air currents. NIH has a publication that gives specific guidance. (orf.od.nih.gov/TechnicalResources/Bioenvironmental/Documents/BiosafetyCabinetBSCPlacementRequirements_508.pdf)
Air Movement. The need for energy conservation drives labs to have lower air exchange rates, but reduced air change rates should be applied judiciously. Set-backs can be used when students are not in labs. Lower air change rates can be utilized when labs are in use if they are monitored by air-sensing devices. Devices that can react quickly to spills or accidents by increasing air change rates and purging noxious odors can provide a safe lab while also reducing energy use.
Teaching labs should be negatively relatively pressurized to keep odors out of corridors.
Safety Equipment. Teaching labs are likely the first labs in which students are exposed to chemicals and other dangerous materials. Students learn what safety equipment in a lab is required and may be used, including emergency showers, eye/face wash, spill kit, and fire blankets; and what everyday practices, such as wearing lab coats and hand-washing, are integral to safety. The location where these items are placed is both a teaching opportunity and a safety consideration. They should be located in a highly visible area that the students see every day and one that is the same in every lab. In an emergency, students should not have to stop and think about the location of safety equipment; it should come automatically. A location near the entrance provides such a place. In addition, the location of a sink at the lab’s exit models standard sink locations in most labs. Refer to ANSI Z358.1 to confirm guidance for the design and installation of emergency showers and eyewashes.
Natural Gas. Consider excluding natural gas from labs. Instructors may be accustomed to having gas in teaching labs to fuel Bunsen burners; however, safer alternatives can be used. Tools and slides can be sterilized in an autoclave or purchased pre-sterilized. Hot plates and heating mantles can be used for heating samples and are more controllable than open flames. When flames are required for certain tests, units with self-contained fuel sources can be used. If natural gas is required, a master cut-off at the teaching station should always be included.
Consider Airflow for Dissection. Biology and anatomy labs often require the dissection of preserved specimens. While the chemicals used to preserve specimens are becoming less dangerous, consideration of how to reduce exposure to fumes should always be considered.
Dissection Stations: Students should be protected from breathing in odors from preservatives. This can be accomplished through snorkels or down-draft stations. Snorkels can be ceiling-mounted, so they don’t necessitate the use of fixed student benches that constrain teaching methodologies; however, they must be positioned correctly to avoid pulling odors past students’ breathing zones. The configuration of a down-draft dissection station puts the specimen between the student and the exhaust, pulling all odors away from the student without special knowledge or set-up. Down-draft stations require fixed benches, so they reduce flexibility within a lab. Depending on pedagogy, back-draft stations can be on student benches, or they can be located at the perimeter of the lab, leaving the option of having reconfigurable student benches elsewhere in the lab.
Storage of Samples: For specimens that are utilized over multiple days, specimen storage will be required. Exhausted cabinets provide a way to keep odors out of the labs and prevent them from building up within a storage cabinet.
Visibility Into Labs and Within Labs. Views into labs encourage student interest in science, but being able to see into the lab is also important for lab safety. Windows into labs allows those in adjacent corridors to see if anything goes wrong in the lab. Knowing that there are sightlines into the labs from public spaces also discourages crimes within the lab. Having good visibility to all parts of the lab allows faculty and students who are in the lab to observe and react to unsafe lab practices or accidents that might occur within the lab.
The perimeter of the room is the best location for fume hoods for creating optimal sightlines within labs; however, if fume hoods need to be located in the middle of the room, glass-sided fume hoods help maintain visibility across the room.
Material Movement through the Building. Locate prep labs to minimize the intersection of student traffic and chemicals/class materials. Consider the movement of course materials from prep labs to class labs. Class materials may need to be moved into labs multiple times a day for different classes and sections, so prep labs with immediate access to teaching labs allow those setting up the labs to avoid moving chemicals through corridors. Pass-thru fume hoods are ideal for moving chemicals into the labs and serving as points for distribution and/or waste removal, confining chemicals to lab environments.
The number, configuration, and distribution of prep labs within a building can contribute to safety. Ideally, chemicals can be moved through the building from loading docks, to prep labs, and into labs without traveling through corridors with student access.
Multiple small prep labs can be distributed around the building and located between labs with immediate access to labs.
A single long prep lab that is located behind all class labs also yields immediate access to labs.
A single centralized prep lab that does not open onto all labs that it serves necessitates thought about how to move materials through corridors, especially when students are present. If this approach is utilized, institutions should develop standard procedures to move materials to labs during off hours or establish separate student-centric areas and staff areas.
Credit: SmithGroup
There are many factors that contribute to the design of safe teaching labs. The first step is to be mindful of lab safety and make it a priority during the planning process.