If you have ever wondered about cremation ashes, this article helps answer the most common questions, including what they look like, smell like, and their colour.
Cremated remains consist of human bone fragments left over after cremation. The body is exposed to extreme heat during the flame cremation process that evaporates all organic matter leaving bone fragments. These bone fragments are then pulverized to create a powder called "ashes."
By contrast, aquamation uses the chemical process of alkaline hydrolysis to reduce a body to bone ash. A combination of water, alkali (potassium hydroxide), heat and pressure is used to create a reaction that speeds up the body's decomposition. The process also creates a sterile liquid that can be disposed of through the sewer or wastewater system. Left over bone is dried and reduced to a powder also called ashes.
Ashes vary slightly depending on the composition of the body. However, the most notable differences are between ashes produced via flame cremation vs. aquamation.
Ashes from flame cremation are usually grey and have a coarse, sand-like consistency (see image above). The colour of the ashes varies; some may be darker or lighter. The colour hue is a result of the temperature of the cremation chamber.
During cremation, the body is exposed to temperatures ranging from 760 to over 980 degrees Celsius or 1,400 to 1,800 degrees Fahrenheit. Bones need to reach a temperature higher than 800 degrees Celsius (1,472 F) to produce lighter-coloured ashes. A larger individual would require higher temperatures and more time to reduce additional fat or muscle. However, the bones may not get to 800 degrees Celsius (1,472 F) during that time. Bones reaching temperatures under 760 degrees Celsius (1,400 F) will likely be black or a dusty brown. Therefore, it is not uncommon for the ashes of a larger individual to be darker.
In contrast, ashes from aquamation are typically white or tan and have a more smooth, powdery consistency. This is because bones do not undergo the same chemical process in aquamation as they do for flame cremation. Instead, they remain closer to the original shade throughout. Additionally, aquamation produces approximately 20 to 30 per cent more ashes than flame cremation.
In most cases, cremated remains are odourless. They may have a slightly metallic odour or some people say they smell somewhat like incense in some cases. However, it is common for ashes to have no distinct smell. Nonetheless, they can take on the smell of the container or cremation urn they are in. For example, if the cremated remains are poured directly into a wood urn, they may begin to smell like the wood over time. This may be less so with a material like glass that does not have a distinct smell.
The ashes of a human adult weigh approximately 4 to 8 lbs (2 to 3 kg) on average. Ashes from women typically range from 4 to 6 lbs, whereas ashes from men often range from 6 to 8 lbs (2.7 - 3.6 kg).
The weight of ashes does not depend on the individual's weight since muscle and fat are destroyed in the cremation process. Therefore, it depends more on factors such as height and bone density. Nonetheless, ashes will often weigh around 3.5 per cent of the individual's original weight.
However, it is important to note that urn choice is dependent on volume rather than weight. You can determine the volume of ashes with the guideline below.
Before cremation, each pound (or half a kilogram) of body weight equals approximately one cubic inch (16.3 cubic cm) of ashes. If someone were 150 lbs (68.04 kg) before cremation, they would need an urn with a capacity of at least 150 cubic inches (2,458.06 cubic cm). However, this can vary depending on the type of cremation chosen. See this ashes calculation article for more info.
Also note that aquamation produces approximately 20 to 30 per cent more ashes, than flame cremation.
Read our urns for ashes FAQ here. Or ask our experts a question about urns, ashes and cremation by emailing firstname.lastname@example.org or to make cremation or aquamation arrangements for a loved one, click here.
Photo credit for image above on this post:
Asurnipal, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons