Fume hoods are one of the most reliable and essential pieces of equipment in your lab. Whether you’re working at a school lab or an industrial setting, a chemical fume hood can turn a catastrophic accident into a minor occurrence. This will show you the purpose of fume hoods, safety tips, and overall information you should know about this essential equipment.
Fume Hood Purpose
A fume hood’s purpose might sound simple, but it’s critically important since any lab accident can be catastrophic. One spilled chemical can lead to lifelong injuries or death in the worst-case scenario.
A fume hood is designed to collect and contain dust, vapor, and fumes. They will then be removed from the air via the laboratory’s exhaust system. When used properly, this will completely remove any airborne fumes and particles in the air so that workers and students are safe.
Different Types of Fume Hoods
There are several different types of fume hoods that all serve the same basic purpose but go about their task in different ways. The most common and simplest to use is called a Constant Air Volume, or CAV, fume hood. These remove fixed amounts of air at all times and regulate the overall volume of air in the room.
There are also Variable Air Volume, or VAV, fume hoods. You can adjust the sash height to alter airflow. These models often come with monitors and there is an emergency purge feature that quickly removes any hazardous fumes or particles.
Most fume hoods look like large metal cabinets, but there are also some walk-in fume hoods that serve somewhat different purposes. They still collect fumes, vapors, and particles for safety, but their main purpose is to keep the work process separate from other parts of the lab. This allows technicians to work on more volatile chemicals without interfering with the rest of the lab.
Fume Hood Limitations
A properly operated chemical fume hood works wonders against gaseous pollutants and particles. At the same time, they have limitations just like any other lab equipment. Anyone who was near the accident may have inhaled the fumes before the fume hood started working. While a hood can minimize the risk here, it can’t completely eliminate it.
Fume hoods only work on the airborne elements of the chemicals and particles. You will still need goggles, aprons, and other personal protective gear for comprehensive safety. While a fume hood isn’t infallible, it is essential for clearing the air of any pollutants.
You must also consider capacity, especially if you’re choosing a ductless fume hood. Ductless hoods are more affordable and are usually adequate for smaller spaces or when working with less dangerous chemicals. At the same time, they tend to have significantly less capacity and airflow than air hoods attached to the ducts.
There are several factors you must check before putting the fume hood to work. You don’t want to discover the hood malfunctions after a chemical spill has occurred. Ensure that all safety certifications have been completed within the last 12 months. If any certifications have expired, then have the fume hood inspected immediately. Ensure that you can safely control airflow and that the model works as expected by testing it out.
Chemical fume hoods come with baffles and some have both upper and lower baffles. These can be adjusted with a lever attached to the hood. Test the baffles and ensure they work as expected. The sash level determines how much air the fume hood regulates. Keep it as low as possible to conserve energy. It shouldn’t be lifted above the arrow for efficient operating unless needed. Ensure the sash level affects the airflow as expected.
Be sure to read the operating instructions for any other parts or functions. You will want to test everything to ensure the fume hood works when needed. You don’t want to find out a critical feature is broken when an accident happens.
Safely Avoid Cross Drafts
An essential aspect of fume hood safety is to avoid cross drafts. Any air currents or cross drafts in the lab can drastically reduce the fume hood’s efficiency. The contaminated air can be pulled away from the hood and circulated back into the lab, which poses a risk to employees and means the fume hood must work harder to remove the hazardous contaminants.
Most cross drafts are made by seemingly innocuous means. They are often formed by open windows and doors, existing air ventilation or even employees moving their arms and bodies near the fume hood. This is often done in an effort to remove the contaminants and might seem helpful, but the fume hood must be unimpeded in its work. These cross drafts must be avoided for peak proficiency.
Fume Hood Maintenance
Another essential aspect of safety is maintaining the fume hood so it’s ready when you need it. Check the airfoil and ensure it’s properly in alignment. It can be knocked out of place and this can significantly impact airflow. It might go without saying, but some people have used fume hoods as storage spaces since they look like cabinets. This should never be done as it can impair or destroy the fume hood.
You must also wash the interior of the hood to avoid any chemicals building up. This is especially important if you are working with explosive or highly reactive chemicals. Many fume hoods have a wash setting. If your model doesn’t come with one, then wash the interior manually. It’s suggested that this be done daily, but check your fume hood’s instructions to see if your specific model suggests a different cleaning schedule.
Fume hoods are one of the safest and most reliable pieces of the lab equipment available. They quickly remove hazardous contaminants from the air and minimize damage from chemical spills. Check our large catalog offume hoodsto find the ideal one for your lab. We offer many different sizes and styles that will suit your industrial needs.