The vacuum hood is a device used in laboratories when carrying out certain analyses to suck in harmful vapours generated by some reaction. Another reason why the fume hood is necessary is when protection from pathogenic microbial agents is required. Two types of fume hoods are used in laboratories:
Chemical fume hood
Laminar flow hood for biological use
Laboratory suction hood for chemical use
The vacuum hood in a chemical laboratory serves to protect the operator from any vapours released by chemical reactions. For example, it may happen that one works with hydrochloric acid, which, in high concentrations, forms acidic vapours. Besides being highly corrosive, these acids can damage the respiratory tract. It is therefore necessary, among many other precautions, for the laboratory to be equipped with a fume hood capable of sucking in the vapours released by the reaction.
There are several substances that must not be inhaled by operators working in the laboratory. These include benzene, sulphur dioxide, nitrogen oxides, formaldehyde, polycyclic aromatic hydrocarbons (PAHs), mercury, silica, radon... and many others. The processing or even certain tests carried out with these substances produce toxic vapours that must not be inhaled by operators. For this reason, fume hoods are used that suck these vapours in and remove them to the outside. The air outlet must be at least 1 metre above the roof ridge.
Suction hoods for biological use
The laminar-flow laboratory hood is used in the biological field to protect the operator and the surrounding environment from biological agents. In most cases these are pathogenic microorganisms. The laminar flow hood sterilises the air inside the hood through the use of HEPA (High Efficiency Particulate Air) filters. These micro fibreglass filters guarantee 100% pure air.
The laminar flow hood is used to protect the operator and his surroundings from biological agents.
There are vertical laminar flow hoods where the air moves in this direction. There are 3 classes of protection:
in class I you protect the operator but not the sample you are working on;
in class II both the operator and the sample are protected, guaranteeing conditions of absolute sterility;
in class III the operator is completely isolated from the sample he is handling so as not to expose him to the risk of contagion of viruses;
The horizontal laminar flow hood is an economical type of hood and is used for work that has a low risk of contamination. Let us now address the subject of fume hoods from an educational and safety perspective
Laboratory fume hoods
Laboratory fume hoods are the most important collective protection devices, necessary and obligatory to protect the health of the operators using them. In fact, they are subject to a high risk of contamination when using dangerous chemical agents.
What are laboratory fume hoods used for?
Laboratory fume hoods are built to reduce at source the environmental concentration of all those substances considered hazardous, such as toxic dusts, fumes, gases and vapours, that can develop in scientific laboratories while research or teaching activities are carried out. The fume cupboards protect the personnel working in them from all the dangerous situations that could occur, such as toxic splashes, fires, explosions, all events that can lead to more or less serious injuries that can cause damage to health. In fact, laboratory fume cupboards can be considered as areas of very high potential danger, where toxic atmospheres can develop inside them, which in addition to being dangerous if inhaled, can be highly flammable or explosive.