Formaldehyde is a colorless, odorless gaseous organic material, if the human body is exposed to formaldehyde for a long time, it can be absorbed through the respiratory system and the mucous membranes of the skin, and it will play a role in the male reproductive system, especially in the spermatogonial tubules of the testicles, resulting in abnormal local sperm production. Organic substances can damage the nucleic acids in spermatozoa, especially DNA, which can be mutated. Prolonged exposure to formaldehyde can cause an increase in the malformation rate of human germ cells. If pregnancy is carried out on top of this, it is easy to produce abnormal fertilized eggs, and if the pregnancy is carried to term, it will result in the formation of malformed babies. Men who have been exposed to formaldehyde for a long period of time are advised to undergo routine semen tests to determine if there are any sperm abnormalities, especially chromosomal and nucleic acid tests.