What percentage of formaldehyde is present in formalin?

40%

The correct answer is option 1. \(40\%\).

Formaldehyde: It is a strong pungent smelling colourless organic substance. It belongs to the category of aldehydes and is a simpler form having chemical formula \(CH_2O\). When in its gaseous state it polymerizes to form paraformaldehyde that is why it is stored in aqueous solution.

Use of formaldehyde:

It has its major application in laboratories as preservative for tissue.

When an individual comes in contact with formaldehyde, it creates a burning sensation in the nose, eyes, throat and individual experiences watery eyes and congestion in the throat.

Formalin: It is a by-product of formaldehyde produced when 37% by weight or 40% by volume of formaldehyde is mixed with water containing 10-15 methanol.

Effect of formalin:

Research has proved that scholars or scientists working in laboratories having high exposure to formalin, has high risk of developing leukemia which is a blood cancer, hence it is categorized as a carcinogen.

Hence after studying about the preparation procedure of formalin from formaldehyde, we come to know that 40% of formaldehyde is present in formalin.