Bio-cremation, also known as chemical cremation, aquamation or resomation, is a relatively new alternative to burial and fire-based cremation. It requires less energy and fewer natural resources than burning a body through traditional cremation or building a coffin and concrete vault.
The technical process is known as alkaline hydrolysis, which is the same natural process that occurs with natural decomposition over time.
Essentially the opposite of fire, the process uses water, temperature and alkalinity to reduce the soft tissues of the body to a liquid form. The chemical reaction converts the proteins, nucleic acids and lipids in all cells of the body into a sterile liquid solution of small peptides, amino acids, sugars and soaps.
It works like this: A corpse is placed into a rigid stainless steel basket within a stainless steel pressurized tube-shaped vessel that is filled with water and an alkali solution of potassium hydroxide and caustic soda. In the unit being considered for use in Cloquet, the solution is heated to 303 degrees Fahrenheit and pressurized to 65 psi. After several hours, all that remains in solid form is the skeleton and teeth -- now easily crushable calcium phosphate -- and a coffee-colored liquid.
The process is fully automatic, similar to a "dishwasher," said Joe Wilson, CEO of Bio-Response Solutions Inc., the company that designed and makes the unit. Wilson said the high-temperature, high-pressure unit he sells uses a total of about 250 to 300 gallons of water, which is flushed down the drain with the approximately 65 gallons of liquid remains. The bone material remains in the stainless steel basket and can be easily retrieved -- and returned to the family in an urn -- along with any metal or electronic parts such as pacemakers and artificial joints. When possible, parts of stainless steel and titanium implants are recycled.
Mercury amalgam fillings remain safely bound in the teeth and are disposed of in an environmentally safe manner, unlike flame cremation, during which the mercury turns to a vapor form and goes up the smokestack, only to fall to the earth again as a contaminate in precipitation.
In Minnesota, alkaline hydrolysis was approved by the state Legislature in 2003 and the first single-unit alkaline hydrolysis machine came online at Mayo Clinic in February 2006. The machine is used to chemically cremate cadavers donated to the clinic.
Terry Regnier, director of Anatomical Services at Mayo, was instrumental in getting the process approved in Minnesota.
Mayo Clinic was also the first facility in the U.S. to have a single-body alkaline hydrolysis unit. Before that, the units had mostly been used for animal disposal, often in larger quantities. The University of Minnesota has a 7,000-pound unit, while the individual units can usually handle up to 500 pounds.
"We wanted to keep the bodies separate, in line with how we handle our donors," Regnier said. "We handle it like I would treat my mother. At the same time, we didn't want to do something the rest of Minnesota could not (do)."
For a long time, Mayo remained the only facility in the state using the process for bio-cremation of human remains. Now, the Bradshaw Celebration of Life Center in Stillwater, Minn., is preparing to use the process.
Regnier said he hopes the state will add standards for bio-cremation to the state statute, which simply says that alkaline hydrolysis shall be "subject to the same licensing requirements and regulations that apply to cremation, crematories and cremated remains as described in this chapter."
He would like to see the state require that such units use high heat and high pressure and operate in sealed conditions.
"That (high heat, high pressure) process works for us," Regnier said. "It helps the chemical go through the bones and reach the places that are hard to reach, (which) takes care of the difficult diseases like prion diseases (such as Creutzfeldt-Jakob disease)."
Both the bones and the liquid remains are sterile after alkaline hydrolysis, he said.