While it may seem a weird question, wondering what happens to a body in a casket is actually rather normal, especially if you or a loved one is facing end-of-life and the many decisions therein.

The decomposition of a body in a casket depends on several variables, not the least of which is how and where the person died. For instance, if the person dies in her hospital bed, then preparation of the body will begin immediately – as soon as the family has had their chance to say their goodbyes, of course – so preservation can be lengthened.

If a person dies alone, whether at home in their bed or outside in the elements, if they are not discovered right away, decomposition, because it begins immediately, will be a fast process.

The Process of Decomposition

By the time you or your loved one is buried or cremated, decomposition has already been occurring. This rate of decomposition relies heavily on the conditions of the environment in which the body has been.

Above-ground decomposition occurs two times as fast as a body in water and four times faster than a body buried under ground. The deeper the burial, the longer the process of decomposition, unless the ground is saturated.


While the process of embalming a body is not stipulated legally, the majority of funeral homes use this process for casket burials, especially if the funeral proceedings will include open-casket viewing.

Once a body has been embalmed, this further slows the process of decomposition. For instance, a body that has been embalmed that is in a room set at 70 degrees Fahrenheit with a fifty percent humidity level will remain intact for up to three days.

Beyond this time, bacteria that were already present in the body will begin to grow once again and break down the chemical agents with the embalming liquid. Today’s embalming liquid, however, utilizes plastic polymers which considerably slow the rate of decay.

In fact, a body that has been embalmed and left in a room with dry air will shrivel and desiccate before decomposition fully takes place, which is how mummies were made in Egyptian times.

Funeral Coffin

Decomposition in a Casket

Decomposition within a casket is normally much slower. People who have had the unfortunate necessity of exhuming a buried loved one several months after a funeral have been quite surprised to see the level at which the body is still recognizable.

The farther below ground you go, the cooler it will be. On average, the temps underground can vary between twenty to fifty degrees cooler than the air temps above.

Some tissues of the body, like tendons or ligaments, do not decay as fast as other parts of the body and reproductive organs can last for several months. Within one year, however, all that will remain is a skeleton with a trace of tissue, and the person’s teeth.

When buried in a casket in optimal conditions, it will take more than forty years for the skeleton to become dry or brittle. If the soil in which the coffin is buried has a neutral acidity the bones can actually last for several hundred years. Acidic soil will eventually dissolve the bones.


The Science Behind What Happens to a Body in a Casket

Buried underground, there is no light and no heat source. Usually, the ground has a measure of moisture. Light, heat, and moisture all play a role in the decomposition of a body. Some people today opt to have their casket, or that of their loved one, lined in cedar wood as a deterrent to insects and rodents. When this is done, it can also affect the rate of decay.

Formaldehyde is one of the chemical agents used in embalming liquid. This chemical is sturdy, in that it does not easily break down. It can, however, be diluted with water. If the burial area is in a damp region, formaldehyde will leave the body sooner – likewise, if the underground temps are warmer than average, this chemical will evaporate into the soil around the casket.

Temperatures that are cooler will allow the formaldehyde to remain within the body, keeping it preserved for much longer. If cedar wood or some other form of insect and rodent deterrent has been used, these pests will not be able to introduce fresh bacteria into the body, also slowing the rate of decay.

There are several details that can affect what happens to a body in a casket. Given optimal conditions, you can expect a body to have fully decomposed to its finest components within three years, but the rate of decay of a body within a casket will depend greatly on the circumstances of the person’s death and whether the body has been embalmed.