Cremated remains are often referred to as “ashes,” but they are not like wood ash. After cremation, the term “ashes” refers to processed bone fragments, not the powdery residue from burning wood. These remains are sterile and pose no biological hazard. This article explores the scientific processes ensuring this sterility, the composition of the remains, and their safe handling.
How Cremation Achieves Sterility
Cremation reduces organic remains to inorganic components through intense heat. The body is placed in a specialized chamber, or retort, where temperatures typically range from 1,400 to 1,800 degrees Fahrenheit (760 to 982 degrees Celsius). This extreme heat ensures the complete combustion and vaporization of all soft tissues, including muscles, organs, skin, and hair, leaving behind only bone fragments.
These high temperatures destroy all organic matter, including microorganisms such as bacteria, viruses, fungi, and parasites. This process eliminates any potential for disease transmission, rendering the remains biologically inert. Sterility, in this context, signifies the complete absence of viable microorganisms.
The process maintains these temperatures for a sufficient duration, typically two to three hours for an adult. This ensures all organic material is thoroughly incinerated, leaving no environment capable of supporting microbial growth. Even the DNA within the remains is obliterated by the intense heat.
What Ashes Are Made Of
The material referred to as “ashes” after cremation is primarily composed of bone mineral fragments. It is not true ash like that from a fireplace, but rather pulverized bone, often having a coarse, sand-like texture. The primary chemical component of these remains is calcium phosphate, the main mineral found in bones, specifically as hydroxyapatite.
Cremated remains also contain smaller quantities of other inorganic minerals, such as salts of sodium and potassium, and trace elements. During the cremation process, water and all organic compounds are vaporized, leaving behind only these non-combustible, inorganic residues.
Because the resulting material is inorganic and lacks water or organic nutrients, it cannot support the growth or survival of microorganisms. This chemical composition ensures cremated remains are sterile and pose no biological hazard. While their appearance can vary, their fundamental inorganic nature remains consistent.
Safe Handling and Disposal
Cremated remains are sterile inorganic bone fragments, making them biologically safe to handle. There is no risk of infection or disease transmission from touching or being near them. Individuals can safely scatter, bury, or keep the remains in an urn without biological concern.
While biologically safe, basic hygiene is still advisable when handling cremated remains. The remains are typically a fine, powdery substance, and inhaling these particles can cause irritation to the throat and lungs. Wearing gloves and avoiding direct inhalation, such as by wearing a protective mask, are prudent measures, though not due to any pathogen risk.
Cremation effectively eliminates biological concerns, allowing for respectful and safe handling in various memorialization practices. The decision of how to handle or dispose of remains is purely a matter of personal preference and local regulations, rather than a health consideration.