The Smell of Death

Few people would argue that nothing smells as foul as a decomposing body.

This is because, during the human decomposition process, dozens of different types of gases are released and eight of these gases are primary contributors to the horrible stench that oftentimes is called the “smell of death.” The primary odors that people associate with a decomposing body are rotting fish, feces, mothballs, rotten eggs, rotten cabbage, and garlic.

Primary Gases That Give Rise to the Smell of Death

These eight gases mentioned above create the six distinctive odors associated with a decomposing body. These gases are: 

• Cadaverine

• Putrescine

• Skatole

• Indole

• Hydrogen sulfide

• Methanethiol

• Dimethyl disulfide

• Dimethyl trisulfide

Cadaverine is one of the two most dominant gases associated with the human decomposition process and a significant amount of cadaverine can be toxic. Although most commonly associated with the purification of animal cadavers, cadaverine is also found in very small quantities in living animals, including humans. Small amounts are found in human urine and semen. Cadaverine has a rotting fish odor.

Putrescine is the second of the two most common gases associated with human decomposition and extensive exposure can be toxic. In addition to being associated with decomposing animals, putrescine can also be found associated with living animals in small amounts. For example, putrescine is found in small quantities in human semen and can be associated with the odor of bad breath. Putrescine also has a rotting fish odor.

Skatole is detectable during the human decomposition process because as remains decay, waste contained in the digestive system is released, which includes the release of feces. Hense, skatole has the odor of feces.

Indole is widely found in the environment. Indole gas is created as a result of the processes of bacteria. During the human decomposition process, bacteria flood a body when their main repositories of intestines and pancreas after death. Billions of bacteria flood the body, resulting in the creation of a considerable amount of indole gas. Indole has the odor of mothballs.

Hydrogen Sulfide is a flammable, potentially explosive, poisonous gas. It is produced when organic matter breaks down in the absence of oxygen, which is the case in the human decomposition process. This gas is also commonly present in swamps and sewers. Hydrogen sulfide has the odor of rotting eggs.

Methanethiol is a colorless but smelly gas derived from the brain and blood of humans and other animals. Methanethiol exists in the brain and blood of living humans and is released from the body during the human decomposition process. Methanethiol has the odor of rotten cabbage.

Dimethyl Disulfide is a foul-smelling gas derived from many sources, including bacteria, fungi, plants, and animals. You might be familiar with this smell as rotting meat gives off this gas. It is the smell associated with dimethyl disulfide that tends to attract flies to a decomposing body. Dimethyl disulfide has the odor of foul garlic.

Dimethyl Trisulfide is commonly is emitted from onions, leeks, broccoli, and cabbage. It is also detectable with decomposing human remains. Dimethyl trisulfide has the odor of foul garlic.

Hazards of a Decomposing Human Body

In addition to dangerous pathogens that can be found in blood, bodily fluids, and other biological matter associated with a decomposition human body, the gases emitted from remains can present at least some threat to the health of living individuals. For this reason, when a person is in the direct vicinity of a decomposing human body, taking appropriate safety precautions is vital. This includes the wearing of appropriate personal protective equipment that includes goggles, gloves, smock/apron/uniform, a respirator, and a mask.

The Stages of Human Decomposition

There generally are considered to be five stages associated with the human decomposition process. These five stages are

• Fresh

• Putrefaction (bloat)

• Active decay

• Advanced decay

• Skeletonization.

The fresh state persists for the first couple of days following the death of a human being. After the second day mark, the putrefaction stage commences. It is at this second stage that the stench of decomposition begins to occur. The smell of death will persist, at least to some degree, up to and until the skeletonization state. Once a cadaver reaches the skeletonization state, virtually everything that is capable of decomposition has decomposed. Thus, there remains virtually nothing in the way of gases to be released from the decomposing human remains.

Understanding the specifics of the human decomposition process is vital when it comes to ascertaining the cause and even time of death. It is also vital in regard to the process utilized to clean up a death scene or to undertake biohazard remediation.