Which laboratory activity would most likely require the use of a fume hood

Fume hood is usually used in the laboratory in order to prevent exposure to hazardous chemicals. Fume hood is like a big cupboard; chemical reactions that produce hazardous products are usually produce inside it. One has to check that fume hood is working correctly before using it. The hood confines hazardous airborne materials, dilute them with a large amount of air and expel them through the exhaust pipe on the roof of the laboratory building.