A fume hood, also known as a fume hood or fume hood, is a large equipment used in laboratories, especially chemical laboratories. The purpose is to reduce the exposure of experimenters to harmful gases. Isolation requires the use of a glove box. The fume hood has the following filtering procedures: filter and remove dust before using foam plastic, filter with activated carbon, and absorb many chemicals. But ammonia and carbon monoxide require other special filtration devices to be removed. The pre filtered material can be used for an average of 6 months, and the activated carbon layer can be used for an average of 2 years, but the specific lifespan depends on the usage situation.