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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 someone'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.
- Glass House (British Columbia) -- a building in British Columbia constructed with empty embalming fluid bottles