Chemical Fume Hoods

The Complete Guide To Chemical Fume Hoods

There are numerous different types of hoods designed for various purposes and environments. For instance, chemical fume hoods prevent the release of dangerous substances into the overall laboratory space. They are exceptionally efficient in the event of an emergency when a hazardous substance spills, as they remove chemicals from the user environment. This article will introduce you to the essentials of chemical fume hoods operating.

How do chemical fume hoods work?

Multiple consumers wonder – what are chemical fume hoods? Generally speaking, these hoods appear as a local exhaust ventilation system. They are the most widespread in laboratories – the primary appliance of a chemical fume hood is to control inhalation exposure to hazardous chemical substances. By preventing the spreading of dangerous materials, this kind of hood works well for exhausting chemicals in the event of an emergency. When used and maintained correctly, such a ventilation system can ensure an advanced level of protection for laboratory occupants.

To understand the operating mechanism of chemical fume hoods, it is essential to glance at their design. A hood consists of the central element – a ventilated enclosure designed to capture and exhaust nanoparticles, vapors, and gases that might be produced within a laboratory environment. The exhaust fans in chemical fume hoods are usually placed outside the building, typically at its top. These fans work to pull the air through the duct that is linked directly to the hood and then exhaust the air into the atmosphere.

Primary types of chemical fume hoods

1. General use in the laboratories

This kind of chemical fume hood can be found in the typical laboratories of general chemistry. They are approved for toxic chemical work and radioisotopes, and carcinogens.

2. Perchloric acid

You risk receiving severe injuries if you work with perchloric acid in a general chemical fume hood environment. Once they are settled on the hood ducts, the acid vapors can produce detonating perchlorate crystals. It would be best to use special hoods made of PVC or stainless steel to prevent accidents. They are equipped with a water wash system that is crucial after every use of the acid in the laboratory.

3. High performance

High-performance chemical fume hoods stand for the features that allow them to work at low air velocities while keeping the energy. Such hoods are usually labeled with a special sticker – it is necessary to inform users that high-performance hoods must be used at the determined air velocity amplitude.

4. Acid-resistant

Another type of chemical fume hood is typically made from the durable material polypropylene, which is designed to resist harsh acids. Once you work with concentrated acids, such as nitric acid or Aqua Regia, or heat them, they appear corrosive for the most general fume hoods. Thus, acid resistance ventilation systems are essential for laboratories that often work with solid acids.