|This article needs additional citations for verification. (November 2008)|
Embalming chemicals are a variety of preservatives, sanitising and disinfectant agents and additives used in modern embalming to temporarily prevent decomposition and restore a natural appearance for viewing a body after death. A mixture of these chemicals is known as embalming fluid and is used to preserve cadavers, sometimes only until the funeral, other times indefinitely.
Typically embalming fluid contains a mixture of formaldehyde, methanol, and other solvents. The formaldehyde content generally ranges from 5 to 29 percent and the methanol content may range from 9 to 56 percent.
How they work
Simply explained, embalming fluid acts to fix (denature) cellular proteins, meaning that they cannot act as a nutrient source for bacteria; embalming fluid also kills the bacteria themselves. Formaldehyde fixes tissue or cells by irreversibly connecting a primary amine group in a protein molecule with a nearby nitrogen in a protein or DNA molecule through a -CH2- linkage called a Schiff base. The end result also creates the simulation, via color changes, of the appearance of blood flowing under the skin.
Modern embalming is not done with a single fixative. Instead, various chemicals are used to create a mixture, called an arterial solution, which is generated specifically for the needs of each case. For example, a body needing to be repatriated overseas needs a higher index (percentage of diluted preservative chemical) than one simply for viewing (known in the United States and Canada as a funeral visitation) at a funeral home before cremation or burial.
Embalming fluid is injected into the arterial system of the deceased. Many other bodily fluids may be drained or aspirated from the body and replaced with the fluid as well. The process of embalming is designed to slow decomposition.
Chemicals and additives
It is important to distinguish between an arterial chemical (or fluid), which is generally taken to be the product in its original composition, and an arterial solution, which is a diluted mixture of chemicals and made to order for each body. Non-preservative chemicals in an arterial solution are generally called "accessory chemicals" or co/pre-injectants, depending on their time of utilization.
Potential ingredients in an arterial solution include:
- Preservative (Arterial) Chemical. These are commonly a percentage (normally 18%-35%) based mixture of formaldehyde, glutaraldehyde or in some cases phenol which are then diluted to gain the final index of the arterial solution. Methanol is used to hold the formaldehyde in solution. Formalin refers specifically to 37% aqueous formaldehyde and is not commonly used in funeral embalming but rather in the preservation of anatomical specimens.
- Water Conditioner. These are designed to balance the "hardness" of water (the presence of other trace chemicals that change the water's pH or neutrality) and to help reduce the deceased's acidity, a by-product of decomposition, as formaldehyde works best in an alkaline environment. Additionally, water conditioners may be used to help inactivate chemotherapy drugs and antibiotics, which may bind to and render ineffectual the preservative chemical.
- Cell Conditioner. These chemicals act to prepare cells for absorption of arterial fluid and help break up clots in the bloodstream.
- Dyes. Active dyes are used to restore the body's natural colouration and counterstain against conditions such as jaundice as well as to indicate distribution of arterial fluid. Inactive dyes are used by the manufacturer of the arterial fluid to give a pleasant color to the fluid in the bottle but do nothing for the appearance of the embalmed body.
- Humectants. These are added to dehydrated and emaciated bodies to help restore tissue to a more natural and hydrated appearance.
- Anti-Edemic Chemicals. The opposite of humectants, these are designed to draw excessive fluid (edema) from a body.
- Additional Disinfectants. For certain cases, such as tissue gas, specialist chemicals Triton-28 arterially injected,and topicals such as Dis-Spray or SaniSol 5 can be added to an arterial solution.
- Water. Most arterial solutions are a mix of some of the preceding chemicals with tepid water. Cases done without the addition of water are referred to as "waterless." Waterless embalming is very effective and not often considered too expensive for everyday cases.
- Cavity Fluid. This is a generally a very high-index formaldehyde or glutaraldehyde solution injected undiluted directly via the trocar incision into the body cavities to treat the viscera. In cases of tissue gas, phenol based products are often used instead.
Prior to the advent of the modern range of embalming chemicals a variety of alternative additives have been used by embalmers, including epsom salts for edemic cases and milk in cases of jaundice, but these are of limited effectiveness.
During the American Civil War, the Union Army, wanting to transport slain soldiers from the battlefields back home for burial, consulted with Dr. Thomas Holmes who developed a technique that involved the draining of a corpse’s blood and embalming it with a fluid made with arsenic for preservation.
Embalming chemicals are generally produced by specialist manufacturers, two of the oldest and biggest being The Dodge Company and The Champion Company. Other companies include Egyptian, now U.S. Chemical, as well as Kelco Supply Company (formerly L H Kellogg), Pierce Chemical Company, Bondol Chemical Company, and Hydrol Chemical Company. There are many smaller and regional producers such as Lear Barber in Sheffield, Genelyn, Frigid Fluid Co., and Trinity Fluids, LLC to name but a few. Some funeral homes produce their own embalming fluids, although this practice has declined in recent decades as commercially available products have become of better quality and more readily available.
Following the EU Biocides Legislation some pressure was brought to reduce the use of formaldehyde. IARC Classes Formaldehyde as a Class 1 Carcinogen. There are alternatives to formaldehyde and phenol-based fluids, but these are technically not preservatives but rather sanitising agents and are not widely accepted.
When an embalmed body is buried and decays, the embalming fluid can seep into the ground and affect the surrounding soil and water ecosystems. Since embalming fluid largely consists of formaldehyde, it is the chemical that has the most dramatic effect on its surroundings. The fluid that is injected into the blood vessels of the cadaver is up to 5% formaldehyde while the fluid injected into the body cavity is up to 50%.
Formaldehyde works to stiffen the tissue of the cadaver, allowing the mortician to pose the body. This is the characteristic that also makes formaldehyde hazardous when encountered in the environment. The carbon atom in formaldehyde, CH2O, carries a slight positive charge due to the high electronegativity of the oxygen double bonded with the carbon. The electropositive carbon will react with a negatively charged molecule and other electron-rich species. As a result, the carbon in the formaldehyde molecule bonds with electron-rich nitrogen groups called amines found in plant and animal tissue. This leads to formaldehyde cross-linking, bonding proteins with other proteins and DNA, rendering them dysfunctional or no longer useful.
Formaldehyde is featured on U.S. Environmental Protection Agency’s list of top 10% worst hazardous chemicals for damaging the environment. It is carcinogenic in humans and animals because the cross-linking can cause DNA to keep cells from halting the replication process. This unwarranted replication of cells can lead to cancer. Unicellular organisms found in the soil and groundwater are also quite sensitive to cross-linking, experiencing damage at a concentration of 0.3 mg to 22 mg per liter. Formaldehyde also affects aquatic invertebrates, with crustaceans being the most sensitive type. The range of concentration damaging them is 0.4 mg to 20 mg per liter. Studies also show that formaldehyde has been known to injure some marine plant life and kill the root systems of some small plants.
Formaldehyde released from the cremation of embalmed cadavers enters the atmosphere and remains suspended for up to 250 hours. It is readily soluble in water so it will bond with moisture in the atmosphere and rain down onto plants, animals, and water supplies below. As a result, formaldehyde content in precipitation can range from 110 μg to 1380 μg per liter.
The growing awareness of the negative effects of embalming fluid on the environment has caused some people to consider green burials where either no harsh chemicals are used in the embalming process or there is no embalming process at all.
- Glass House (British Columbia)—a building in British Columbia constructed with empty embalming fluid bottles
- Sehee, Joe (2007). Green Burial: It's Only Natural, PERC Reports, Winter 2007. Retrieved on 2013-11-06.
- Chiappelli, Jeremiah; Chiappelli, Ted (2008). "Drinking Grandma: The Problem of Embalming". Journal of Environmental Health (71).
- Martin, Andrew (July 20, 2011). "Despite Risk, Embalmers Still Embrace Preservative". Newspaper – via The New York TImes.
- "Molecular Level Answers: The Real Reason Why Formaldehyde is Toxic--and how to avoid it". drholly.typepad.com. Retrieved 2015-11-28.
- "Formaldehyde (HSG 57, 1991)". www.inchem.org. Retrieved 2015-11-28.
- Division, US EPA, ORD, Integrated Risk Information System. "Formaldehyde CASRN 50-00-0 | IRIS | US EPA, ORD". cfpub.epa.gov. Retrieved 2015-11-28.
- Shea, Neil (July 2008). "Dying to Be Green". magazine – via National Geographic.