Fume Hood Safety Series: What Causes Fume Hood Fires—and How to Prevent Them

Chip Albright, founder and president of Fume Hood Certified; 2025 Lab Design Conference workshop leader; Fume Hood Risk Mitigation Digital Conference speaker

Chip Albright, founder and president of Fume Hood Certified, is a globally recognized authority in laboratory safety and equipment, specializing in fume hood performance. With more than 40 years of industry experience, he offers extensive knowledge of safety standards, regulations, and cutting-edge technological advancements. In this final installment of Chip’s Fume Hood Safety Series, he shares valuable insights and cautions for professionals involved in laboratory design, construction, and renovation.

Chip will be leading a workshop on “Validating Fume Hood Safety and Mitigating Risk” at the 2025 Lab Design Conference in Denver on May 11. Register now to secure your spot in this workshop, as space is limited! (Please note: This workshop is a separate add-on to your Lab Design Conference ticket.)

Additionally, you can watch Chip’s free on-demand webinar, “Your Chemical Fume Hood Is On Fire: What Do You Do?” from the Fume Hood Risk Mitigation Digital Conference. Register now to access the free webinar, and contact us at aia@labdesignconference.com to earn AIA LU/HSW credit for completing the video.

---

Fume hood fires are not only dangerous, but they are also costly and disruptive, leading to injury, equipment damage, and the potential loss of valuable research. Despite the critical role fume hoods play in lab safety, they remain among the most misunderstood and misused safety devices in laboratories. Understanding what causes fume hood fires and how to prevent them is essential to protecting both people and property.

Common causes of fume hood fires

1. Incompatible chemicals and reactions: Fires often begin when incompatible chemicals are mixed or improperly stored inside the hood. Flammable solvents, oxidizers, and reactive metals can combust under the right conditions, particularly if safety protocols aren’t followed.

2. Overcrowded or cluttered workspaces: When a fume hood is cluttered with equipment, containers, or unnecessary items, airflow can be disrupted. This increases the risk of vapors escaping into the room or accumulating inside the hood, creating a flammable environment.

3. Poor containment and turbulence: A fume hood’s safety depends on its ability to capture, contain, dilute, and exhaust hazardous substances. Turbulence—caused by room air instability, open doors, or improper user technique—can lead to a loss of containment, allowing flammable vapors to leak and ignite.

4. Electrical malfunctions or heat sources: Using non-explosion-proof electrical equipment inside a fume hood can easily ignite flammable vapors. Additionally, heating elements or open flames used too close to volatile substances can spark a fire.

5. Improper user behavior or lack of training: Untrained users may leave the sash open too wide, block airflow with their body, or fail to recognize signs of poor performance. Many institutions focus on regulatory compliance rather than comprehensive training and cultivating a true safety culture.

Strategies to mitigate fire risk

1. Prioritize containment over face velocity: Safe fume hood performance is less about how fast air moves and more about how well the hood contains hazardous substances. Testing should emphasize containment, using dynamic methods that simulate real-world conditions—not just static face velocity measurements.

2. Maintain clean and uncluttered hoods: Limit the materials inside the hood to what’s necessary for the immediate task. Equipment and chemicals should not block airflow or sit too close to the sash.

3. Use appropriate equipment: Always use explosion-proof electrical devices and avoid open flames near flammable chemicals. Heating should be done with care, and only when it’s safe and necessary.

4. Conduct regular performance testing: Utilize tools like the ASHRAE 110 protocol and Tri-Color Airflow Visualizer to assess performance in real conditions. Testers should be able to diagnose containment issues and recommend actionable fixes.

5. Train users thoroughly: No one should be allowed to work at a fume hood without proper training. Users must understand how the hood works, how to work safely within it, and what to do in case of an emergency.

6. Develop and practice emergency procedures: Emergencies aren’t clean or predictable. Having policies and conducting regular drills ensures that lab staff know how to respond quickly and effectively if something goes wrong.

In short, prevention is a bargain—fires are expensive. By shifting from a compliance mindset to a safety culture built on training, testing, and containment, labs can drastically reduce the likelihood of fume hood fires and protect what matters most. Safety is no accident.