Between the chemical fume hood and the glove box, which one should be used for chemical handling in the laboratory? When handling dangerous substances or hazardous products during laboratory processes, these types of protective equipment are used. The chemical fume hood only protects the operator. The glove box is used to protect the handling/products, the personnel and the environment. Therefore, it is necessary to select your equipment according to your applications.

Chemistry Fume Hoods to Protect Operators

A chemical fume hood works by extracting the chemical fumes released during the process, then capturing and filtering the toxic or undesirable molecules or particles. This protects your laboratory operators from these emissions. There are open chemical fume hoods, but also fume hoods that need to be connected to an extraction network.

An extraction cone, filters, fans, and exhaust air ducts are the main components of a chemical fume hood. The cone should be placed above the work surface to better suck out the chemical emissions during the operation. The fume hood can be equipped with side walls or hood booths that serve as beacons for the work area. Filters treat these emissions and remove particles and elements potentially harmful to the operator. The exhaust air is discharged to the outside through the exhaust ducts.

Air treatment can be done in two ways with a chemical hood:

  • By an activated carbon filter or a particle filter: in these cases, the filters capture the toxic elements before rejecting the exhaust air within the room.
  • By an extraction system: in this case, the ducts must be connected to the outside exhaust system so that they reject the stale air, whether or not it has been filtered beforehand, outside the room.

Each chemical fume hood is equipped with several filters, including a pre-filter and a main filter. The first traps large particles and the second captures the remaining smaller molecules. The main filter of the fume hood can be an EPA, HEPA, ULPA, activated carbon or ultraviolet filter, among others. Commonly used filters are HEPA and ULPA, which remove up to 99.97% of particles smaller than 0.3 µm and 99.99% of particles smaller than 0.12 µm, respectively. It is mandatory that they comply with the NF EN 1822 – 1 standard.

If the laboratory process does not need a closed volume or the average exposure value of the most toxic product used or TWA is higher than 400 ppm, you can use a chemical fume hood.

Glove Box to Protect Processes, Operators and the Environment

Compared to the fume hood, a laboratory glove box is a piece of equipment that guarantees a very high level of safety. This sterile, hermetically sealed mini-environment is used to secure products or processes, but also to protect laboratory personnel and the environment.

By using a glove box, your operators can handle hazardous or sensitive samples and materials without taking any risks. They do not come into direct contact with these substances thanks to the gloves attached to the transparent work surfaces. In other words, they intervene from the outside to prevent any risk of contamination. In addition, the volume of work can be controlled.

In addition to the transparent sides and the integrated gloves, the fume hood integrates {this section is about glove boxes?) various components:

  • gas purifiers to decontaminate the environment;
  • transfer airlocks to introduce and remove materials, products and samples to be handled without breaking the containment;
  • controllers for process control and monitoring;
  • automatic safety systems;
  • other additional accessories depending on the application.

The laboratory glove box becomes indispensable when the process has a TWA of less than 1 ppm. The same is true for all operations requiring a closed volume and not an open environment such as the chemical fume hood. However, the same glove box is not used for handling hazardous samples and sensitive products.

  1. For the containment of hazardous substances, the laboratory glove box designed for this purpose is used. This is the glove box used to handle pathogens, carcinogenic substances, infectious, toxic and allergenic products, radioactive materials, etc.
  2. To confine substances in an inert atmosphere: the glove box is used under argon or nitrogen. As its atmosphere is free of oxygen, water and traces of solvents, it allows the handling of sensitive products, hygroscopic, oxidizable or pyrophoric compounds and materials.

Summary

You can use a laboratory glove box or a fume hood to secure certain chemical manipulations. However, where the chemical fume hood only protects the operator, the glove box is a much safer device to protect the product, the handler and the environment at the same time. The glove box is a separate enclosure that avoids any exposure to the open air and all sources of contamination.