Humans have been cremating their loved ones since the Stone Age, but we have advanced significantly from the fire pits they once used. Modern cremation is a surprisingly technologically advanced process, strictly regulated to ensure safety, consistency, and dignity for the deceased.
From the delivery of a body to a funeral home to receiving the cremated remains, the entire process generally takes about 10–15 days. However, most of this time is spent on paperwork. A death certificate must be obtained from the government, cremation authorization is required, and the deceased’s next of kin must approve everything. Depending on the state where the cremation occurs, there may be a mandatory waiting period of 24 to 48 hours.
Another factor in the cremation timeline is if the deceased wishes to donate their body to science. In this case, any organs and tissues suitable for transplants will be removed, and the body may be retained for up to three years for research purposes. After this period, cremation is typically performed at no cost to the family. All these steps precede the actual cremation process itself, which usually takes a few hours. This duration depends on the condition of the body and the specific type of cremation, which, surprisingly, does not always involve fire.
The process of burning a body
Cremation essentially removes all parts of the body that would otherwise decompose, burning everything except the bones, reducing an adult human body to just four to six pounds of ashes. Most of the lost weight is actually water, accounting for about 60% of each human body. The body’s tissues and organs are vaporized, producing carbon and sulfur gases. Thus, in the simplest scientific sense, cremation is the transition of matter from solid to gas.
Today, all cremations performed in the United States follow a strict process. The body must be placed into a cremation container, which could be as simple as a cardboard box or as ornate as a burial casket. However, most state laws require that the body be enclosed in some kind of combustible container for cremation. The container is then placed in a cremator, a powerful furnace that can reach temperatures of 1,500–1,900 degrees Fahrenheit, similar to those found in the thermosphere.
Depending on the size of the body and the type of cremator, the actual combustion process may take 1–4 hours. At the end, only the bone fragments, primarily composed of heat-resistant calcium phosphate, remain. These are left to cool, after which they are ground into a fine powder. Thus, the remains commonly referred to as “ashes” are actually pulverized bones.
There’s another way to cremate a body
Traditionally, cremation refers to burning a person’s remains in a fire, but in recent years, a new method known as water cremation has gained popularity. The idea of using water to cremate a body might sound counterintuitive, but it is a scientific process called alkaline hydrolysis.
In an alkaline hydrolysis cremation, the body is placed in a sealed container and surrounded by a heated liquid solution composed of 95% water and 5% of an alkaline chemical, such as sodium hydroxide, potassium hydroxide, or a combination of both. This causes the body’s tissues and organs to break down, leaving only the bone fragments. It’s essentially a sped-up version of natural decomposition. There are two types of water cremation: low-temperature alkaline hydrolysis, which takes 14–16 hours in a sub-boiling solution, and high-temperature alkaline hydrolysis, which takes 4–6 hours in a high-pressure boiling solution.
Water cremation is now legal in 26 U.S. states and is quickly gaining popularity as a more environmentally friendly alternative to traditional cremation. A single flame-based cremation can release over 500 pounds of carbon dioxide into the atmosphere, accounting for both the vaporized body tissue and the emissions from the combustion process itself. Water cremations not only avoid this but also produce a liquid runoff filled with organic matter that serves as excellent fertilizer. This way, one lost life can nurture new life in the future.
