Laboratory environments are uniquely dynamic workplaces, and with that comes an ever-present responsibility to manage risk. Whether researchers are working with infectious agents, volatile solvents, or regulated chemical substances, the potential for exposure is real, and the consequences of inadequate safeguards can be severe. Biological hazards such as exposure to blood, body fluids, and other potentially infectious materials represent a significant concern for laboratory workers, while chemical hazards carry the risk of acute and chronic disease, risks that may be compounded in laboratory personnel with preexisting medical conditions.i
Controlling these risks requires more than a well-stocked first aid kit or a posted safety sign. It demands a systematic, layered approach built on established regulatory frameworks, engineering excellence, and a deeply ingrained culture of safety. The following best practices provide a comprehensive foundation for laboratories committed to protecting their personnel, their environments, and the integrity of their work.
Understanding the Two Primary Risk Categories
Effective laboratory safety begins with a clear understanding of the hazards present in any given workspace. The two most consequential risk categories in most laboratory settings are biological hazards and chemical hazards, each requiring distinct controls, protocols, and equipment.
Biological hazards encompass exposure to live microorganisms, infectious agents, blood-borne pathogens, and other potentially infectious materials. Laboratories conducting research with these agents must follow strict containment protocols to prevent accidental exposure.ii The Centers for Disease Control and Prevention (CDC) and the National Institutes of Health (NIH) have established four biosafety levels (BSLs) that define appropriate containment practices for agents known to cause laboratory-acquired infections.iii BSL-1 applies to agents posing minimal risk to healthy adults, while BSL-4 is reserved for dangerous agents that pose a high risk of life-threatening disease transmitted by aerosol, for which no vaccine or therapy exists.
Chemical hazards present a parallel set of concerns, spanning flammable solvents, corrosive acids, toxic gases, carcinogens, and reproductive hazards. OSHA’s permissible exposure limits (PELs) represent the maximum concentration of a chemical to which an employee may be exposed over an 8-hour workday or 40-hour workweek; these limits may also carry short-term exposure ceilings not to be exceeded at any point.iv Understanding the specific hazards present in a laboratory, along with the regulatory thresholds that govern them, is the essential first step in building a meaningful safety program.
The Hierarchy of Controls: A Priority Framework
One of the most important principles in laboratory safety is prioritization. Not all controls are created equal, and the most effective programs are built around the Hierarchy of Controls, a framework that ranks protective measures from most to least effective.v The hierarchy moves from elimination and substitution at the top, through engineering controls and administrative controls, down to personal protective equipment at the base.vi
Engineering controls occupy a privileged position within this hierarchy for good reason. These controls involve making changes to the work environment or equipment itself to reduce hazard exposure at the source.vii Because they do not rely on worker behavior for their effectiveness, engineering controls are the most reliable long-term solution available to laboratory managers. Administrative controls and PPE, by contrast, depend heavily on consistent human compliance, a variable that no safety program should take for granted.
The practical implication is straightforward: laboratories should invest first in engineering solutions, use administrative controls to reinforce safe behaviors and procedures, and reserve PPE as a final complementary layer rather than a primary defense.
Engineering Controls: Fume Hoods and Biological Safety Cabinets
Among engineering controls, two devices stand out as cornerstones of laboratory containment: chemical fume hoods and biological safety cabinets (BSCs). Both represent purpose-built solutions to their respective risk categories, and both require proper selection, installation, maintenance, and use to deliver the protection they are designed to provide.
Chemical fume hoods are often the primary control device for protecting laboratory workers when handling flammable and harmful or potentially harmful chemicals.viii By drawing air away from the worker and toward the exhaust, fume hoods capture and contain chemical vapors before they can disperse into the laboratory atmosphere. OSHA’s Occupational Exposure to Hazardous Chemicals in Laboratories standard (29 CFR 1910.1450) requires that fume hoods be maintained and functioning properly whenever they are used. Periodic performance verification, including face velocity testing, is not optional; it is a regulatory and safety imperative.
Ductless fume hoods represent a particularly versatile solution, utilizing activated carbon filtration to adsorb chemical vapors at the point of generation without the need for external ductwork. For these systems, filter integrity is paramount. To maximize lab safety, activated carbon filters should be replaced approximately every 12 months, while HEPA filters typically carry a service life of one to two years, though actual replacement intervals will vary based on laboratory environment, chemical loading, and usage patterns. Even when a ductless hood is used infrequently, filters should be replaced at their maximum recommended service life to ensure continued protection.
In biosafety applications, biological safety cabinets serve as the primary engineering control. Properly maintained BSCs, used in conjunction with sound microbiological technique, provide an effective containment system for the safe manipulation of moderate- and high-risk infectious agents at BSL-2 and BSL-3.ix BSCs protect laboratory personnel and the immediate environment from infectious aerosols generated within the cabinet, a hazard that is invisible to the naked eye and particularly difficult to control through behavioral measures alone. Cabinets should be certified at installation and at regular intervals thereafter.
While both ductless or ducted fume hoods and biological safety cabinets are critical engineering controls for mitigating laboratory risks, they are not interchangeable. Biological safety cabinets do not protect against chemical vapors, and standard chemical fume hoods do not provide the HEPA-filtered recirculation needed for BSL-1, 2, 3 containment. Selecting the correct containment device for the hazard at hand is a foundational safety decision.
The Chemical Hygiene Plan: A Mandatory Framework
For laboratories working with hazardous chemicals, the Chemical Hygiene Plan (CHP) is not a best practice; it is a legal requirement. A comprehensive CHP details the specific safety measures required for each class of chemicals used in the laboratory, encompassing engineering and work practice controls, PPE requirements, and waste management procedures.x
Critically, OSHA requires that a risk assessment be conducted for each task performed in the laboratory, an assessment that drives the selection of appropriate controls and ensures that protection is matched to the actual hazard presented by each procedure.xi
It is within this framework that engineering controls earn their most important role: a well-maintained fume hood or biological safety cabinet is often the primary control a CHP identifies for reducing employee exposure at the source, making equipment selection, performance verification, and filter maintenance not merely operational concerns, but compliance imperatives.
Personal Protective Equipment: The Final Layer of Defense
Personal protective equipment is applied when engineering and administrative controls are insufficient on their own to reduce exposure to acceptable levels.xiii PPE encompasses a range of safety accessories, including safety goggles, laboratory coats, gloves, respirators, and specialized footwear, designed to protect individuals from specific chemical, biological, and physical hazards.xiii
It is essential, however, that PPE not be treated as a substitute for stronger upstream controls. Laboratory personnel should use PPE in conjunction with engineering and administrative controls to minimize risks effectively.xiv PPE selection must be matched to the hazard: chemical-resistant gloves and a face shield are appropriate for handling corrosive acids; puncture-resistant utility gloves, water-impermeable shoe coverings, and a full-face respirator or HEPA-filtered mask are required for work with BSL-3 agents.xv
Common PPE compliance failures observed in laboratory environments include staff working at benches without gloves, handling contaminated objects while gloved (such as telephones or door handles), and wearing laboratory coats outside designated work areas.xvi Reinforcing correct behavior requires not only training at onboarding, but ongoing, visible commitment from laboratory management and regular observation of day-to-day work practices.
The Safety Program as an Organizational Commitment
Ultimately, the most effective laboratory safety programs are neither document-based nor equipment-based; they are culture-based. A well-written safety manual that defines the program, identifies responsible individuals, and communicates expectations to all employees is the essential foundation.xvii But documentation alone does not create a safe laboratory. Management must commit to the program, provide the necessary resources, assign clear oversight and accountability, and model the behaviors the program requires.
Regular safety audits, with documented corrective actions for identified violations, ensure that the program remains current, that equipment is functioning, and that personnel continue to apply safe work practices.xviii Standard operating procedures should be reviewed and updated as laboratory procedures evolve, chemical inventories change, or new hazards are introduced. Safety is not a static achievement; it is an ongoing organizational practice.
Protecting Your Laboratory with Air Science
Air Science has long supported laboratories in their commitment to safety through a comprehensive range of containment and filtration solutions. From ductless fume hoods engineered for chemical vapor control, to biological safety cabinets designed for BSL-2 and BSL-3 containment, to high-performance HEPA and ULPA replacement filter cartridges, Air Science provides the tools laboratories need to implement engineering controls that work.
Selecting the right containment equipment, maintaining filters on a disciplined schedule, and aligning every product choice with the specific hazards of the laboratory environment are the decisions that translate safety policy into safety performance. Air Science’s team is equipped to help laboratories navigate those decisions.
Explore Air Science’s range of fume hoods and biological safety cabinets or learn more about laboratory safety best practices in our “Fume Hood 101” guide.