Why does burnt hair smell like popcorn?

Answered by Jason Smith

When hair is burnt, it emits a distinct smell that is often described as resembling popcorn. This unique odor can be attributed to a variety of factors, including the composition of hair and the chemical changes that occur when it is exposed to heat.

Hair is primarily composed of a protein called keratin, which is made up of various amino acids. One of the amino acids found in keratin is cysteine, which contains sulfur. When hair is exposed to high temperatures, such as when it is set on fire, the heat causes the sulfur atoms in cysteine to undergo chemical reactions.

These chemical reactions result in the production of volatile sulfur compounds, which are responsible for the distinctive smell associated with burnt hair. One of the most common volatile sulfur compounds produced during this process is called methanethiol. Methanethiol has a strong odor that is often described as being similar to that of popcorn or corn chips.

It is important to note that the smell of burnt hair can vary depending on various factors such as the individual’s hair type, the presence of hair products or chemicals, and the intensity of the heat. While the popcorn-like smell is commonly associated with burnt hair, it is not the only possible odor that can be produced. In some cases, burnt hair may emit a more acrid or unpleasant smell.

Personal experiences can also provide insights into the smell of burnt hair. Many people have encountered the smell of burnt hair in unfortunate situations, such as accidentally singeing their hair while styling it with hot tools or being near a fire incident. The distinctive aroma of burnt hair can be quite memorable and can evoke strong reactions in individuals who have experienced it.

The smell of burnt hair resembling popcorn can be attributed to the chemical reactions that occur when hair is exposed to high heat. The sulfur-containing amino acid cysteine in hair undergoes chemical changes, leading to the production of volatile sulfur compounds, such as methanethiol, which gives burnt hair its unique odor. However, it is important to remember that the smell of burnt hair can vary depending on individual factors and circumstances.