A laboratory is a building where experiments are conducted. There are many kinds of laboratories, and each type is used for performing a particular type of tests. The two major types are the chemistry lab and biology labs. These chemistry labs involve experiments that use toxic substances and thus care should be taken during the performance to prevent accidents. In a biology lab, most tests aren’t as toxic as in chemistry labs. However, care should also be taken to avoid wastefulness and ensure that the safety of the user is assured.
Alaboratory fume hoodis an enclosure that is built inside a chemistry lab for conducting experiments that release toxic chemicals. A fume hood is also used to store volatile compounds that can be harmful to the environment. A laminar flow hood, on the other hand, is also an enclosure built mostly in a biological lab for conducting of experiments that involve delicate microorganisms. It is used to create a sterile environment for doing biological experiments. It is also called a biosafety cabinet.
Let’s take a closer look at the two, and differentiate between their working principles and uses.
There are different kinds of flow hoods commonly used in the laboratories. They are divided into three main classes.
- Class 1. In these types of flow hoods, the air flows from the lab towards the surface where the experiments are conducted
- Class 2. In this flow hood, air flows from the lab towards the chamber. Fresh air then enters the chamber from above. The exhaust air is then HEPA filtered before release to the environment through the exhaust fume hood. The air can also be recirculated inside the chamber.
- Class 3. These kinds of biosafety cabinets are used in labs where delicate experiments are conducted. Both the air entering the chamber and the air exiting are passed through HEPA filters to ensure that it is free from contamination.
This kind of flow hood is not only used in biological labs. It is also a standard component in electronic manufacturing labs where it is used to create a non-contaminated environment that is required during assembling of electronics.
The equipment is also essential in a microbiology lab. Laminar flow hoods are used to ensure that the air required in handling specific microorganisms such as antisera is clean and free from contaminants.
A horizontal laminar flow hood is used in pharmaceutical companies to create an aseptic environment for the handling of sterile products. The horizontal laminar flow hood is fitted with HEPA filters that continuously bathe the working deck with fresh air. This aids in the removal of microorganisms that can interfere with the experiments. The air from the laminar flow hood exits the chamber via an exhaust fume hood.
The most common fume hoods are bypass hoods. These are designed to operate at a constant volume of air. There are numerous kinds of bypass fume hoods including auxiliary air, high performance, and reduced air volume hoods. The fume hoods have an efficient air exhaust system that allows expulsion of toxic gases.
Some fume hoods are specially made to handle specific corrosive substances such as hyperchloric acid. Others have specifications that enable handling of radioactive materials and are fitted with filters to prevent the release of these elements to the environment.
A laboratory fume hood is widely found in many analytical chemistry labs where experiments that release toxic gases such as sulfur dioxide gas are released.
It is also ideal for performing experiments that involve chemicals that easily sputter out during heating. Such compounds can easily burn the lab technician and other lab occupants when conducted in the open space.
The other kind of experiments that should be conducted inside a laboratory fume hood are ones that involve flammable chemicals. These chemicals can be deadly when exposed to the air.
Aerosols, carcinogens, and other volatile chemicals are also handled within this enclosure.