Handling chemicals in the laboratory often involves the use of special equipment such as a fume hood and glove box. Their role is to protect products or operators and the environment. But what equipment should be used for what use? Their uses should not be confused when choosing the right equipment.
The Laboratory Fume Hood
In laboratory processes, a fume hood is used only to protect the operator, especially when the products or compounds give off toxic vapours, gases or aerosols. It sucks out these toxic emissions so that the person in charge of the process is not exposed to them. The system is open and can be optionally connected to the outside.
Components of the Chemical Fume Hood
Laboratory fume hoods usually have an extraction cone, integrated filters and adjustable ventilation and exhaust air systems.
- The extraction cone extracts unwanted vapours and gases from the working area.
- Depending on the type of fume hood used, activated carbon filters or particle filters treat hazardous vapours.
- The evacuation system, consisting of ducts, evacuates the air previously treated or not to the extraction network. The treatment is not systematic.
Filters: A Guarantee of Efficiency?
A laboratory fume hood will be more or less efficient depending on the filters it is equipped with. First, there is a pre-filter that eliminates dust and other large particles, then there is the main filter that captures the remaining particles. The regulatory filters need to meet the required standards.
Depending on the application, the fume hood can be equipped with:
- EPA air filter: capable of removing up to 95% of particles larger than 3 µm.
- High efficiency or HEPA air filter: capable of removing up to 99.97% of particles larger than 0.3 µm, i.e. those of class H13 and H14.
- Ultra-Low Penetration Air Filter or ULPA: capable of removing more than 99.99% of particles larger than 0.12 µm.
- Activated carbon filter capable of eliminating unwanted gases, vapours and odours, but also other chemical elements (e.g. acids, bases, solvents, etc.).
- Ultraviolet or UV filter: capable of eliminating all micro-organisms (bacteria, germs, microbes, moulds, viruses, etc.).
In which cases should a laboratory fume hood be used? The TWA or Average Exposure Value of the most toxic product is used to choose the appropriate protective equipment. The chemical fume hood is recommended when it is above 400 ppm. It can also be used if the operation implemented does not require a closed system. To use the fume hood, simply install the device above the equipment or workstation.
The Laboratory Glove Box
Unlike the fume hood, the laboratory glove box has a completely enclosed volume. Its function is to protect the product, the operator and the environment. Its tightness guarantees a high level of containment for sensitive products or hazardous processes. The inside atmosphere can be controlled, processes are not at risk of contamination from the outside. Laboratory operators and the external environment are protected from dangerous or toxic fumes.
Principle of Operation
A glove box differs from the laboratory fume hood in its design and operation. The device has several transparent side walls as work surfaces. As the containment is enclosed, operators can access the work area through the gloves attached to it. It is equipped with purification systems for decontaminating the environment. It is also equipped with communication systems for the moving products and has instruments that guarantee the continuity of containment. Regulators facilitate the configuration of the glove box for monitoring and control of handlings.
Automatic safety systems prevent possible leaks or other incidents. Thanks to these various components, extremely sensitive substances, volatile, toxic or radioactive chemical compounds can be handled within the laboratory glovebox.
Which Glove Box to Choose?
It is clear that the glove box is much more reliable than the laboratory fume hood for safe chemical handling. But there are two types of glove boxes: the glove box for inert atmosphere containment and the glove box for the containment of hazardous substances.
- Containment in an inert atmosphere: allowing the handling of hygroscopic, oxidizable or pyrophoric materials and substances under ultra-pure atmosphere (under argon or nitrogen).
- Containment of dangerous substances: allowing the handling of pathogens, carcinogenic substances and other infectious substances, but also toxic and allergenic products, radioactive materials, etc.
It is preferable to make contact with reliable glove box manufacturers to obtain the equipment needed. For example, Jacomex is a world leader in this sector. This company offers standard glove boxes and manufactures high-quality custom-made glove boxes. These containment enclosures can meet all your needs, whether you are in the industrial, energy, nuclear, pharmaceutical-medical or research and development sectors, etc.
Which Applications for a Glove Box?
A glove box is better than a laboratory fume hood for all manipulations involving risky products or a controlled atmosphere. It is also preferable if the TWA of the process is less than 1 ppm. In these cases, a glove box is the equipment choice that can guarantee a high level of safety for the manipulations or for the operators and the environment.