How does formaldehyde used in embalming works

The formaldehyde used in embalming is a liquid made by combining methanol, methylene glycol and various other chemicals. The formaldehyde solution used in embalming is typically 37% formaldehyde, which can be diluted to any concentration with water. Embalmers use a number of methods to alter the appearance of dead bodies. The most common method today is arterial embalming, which makes them look more lifelike by replacing their blood with preservative solutions such as these solutions containing formaldehyde.

Physical properties of formaldehyde

1. Melting point: -19℃

This formaldehyde compound has a melting point of -19 ℃. This melting point is lower than other forms of formaldehyde, such as isocyanate, which melts at about -4 ℃. It has also lower solubility in water than other forms of formaldehyde, which means that it can be more easily absorbed into the body after death. This is formaldehyde used in embalming.

2. Boiling point: 102-110℃

The boiling point of formaldehyde is between 110-152 ℃, 92% formaldehyde has a boiling point of 144 ℃. This temperature range occurs because the -HCHO group and two R groups (formyl and methyl) exist in the same plane, which is why the -HCHO group is known as a diene; this allows for easier rotation (boiling point). The boiling point of formaldehyde rises when the bond between the -HCHO group and the R groups is stronger, like in this particular molecule because of an increased bond strength between the methyl and formyl groups. When these bonds are stronger, there is a higher boiling point.

Formaldehyde is both naturally produced as a metabolic product via the aldehyde dehydrogenase pathway, and artificially produced as a chemical precursor to other organic chemicals. Formaldehyde is also used in biological research and histology staining; it is frequently used to fix tissue and cell samples by cross-linking amino acids within proteins, preventing them from becoming distorted or denatured by environmental factors.

3. Thermal Conductivity: 19.7W/m·K

Formaldehyde is well known for its strong thermal properties, when it comes to dissipating heat; due to it being nonpolar, it is able to gain heat easily and quickly transfer it away from the body. Due to this property, formaldehyde is commonly used in embalming as a preservative because of its ability to easily transfer heat from the body and not affect the body's proteins or DNA, which contains higher order structure than proteins or nucleic acids.

4. pH-1: 12.0

Formaldehyde is soluble in water at a pH of 1, which allows formaldehyde to be absorbed into the body and cause the death of tissues. Formaldehyde's low melting point, high vapor pressure and nonpolarity allow it to easily evaporate from the body and cause death. Formaldehydes are often used for embalming because they are easily absorbed into dead bodies; such as when perfuming a corpse. This is because compounds like formaldehyde have low boiling points, which makes them easier to evaporate from the body than other compounds such as sugars that require an elevated boiling point in order to evaporate from a body, causing decomposition of the body over time.

Uses of formaldehyde

1. Bactericidal

Hemoglobin, lipids and enzymes have been shown to be destroyed by formaldehyde. Formaldehyde is a weak oxidizing agent and can thus act as a bactericidal, which is why it is used in the process of preservation and embalmment.

2. Antiseptic and disinfectant.

Formaldehyde causes a reaction with certain body fluids that results in the precipitation of matter formed by the reaction with formaldehyde; this precipitation often causes discoloration of body fluids, but it makes the body process dead cells more efficiently after death.

3. Preservative.

Formaldehyde is used as a preservative in embalming because it prevents bacterial growth, preserves the body from natural decomposition and slows down death from animals and insects.

4. Fixative for tissue and cell samples.

Formaldehyde reacts with amino sugars in proteins, which causes cross-linking of amino acids, thus preventing proteins from becoming denatured by environmental factors such as temperature or pH level change; this allows cells to be fixed, so that they may be studied in a microscope after death by other professionals such as pathologists.

5. Cosmetic and personal care product.

Formaldehyde has many uses in cosmetic and personal care products such as hair straighteners, shampoo, nail polish remover, eye shadow and nail polish;it is usually used as a preservative in cosmetics to prevent bacteria growth. Formaldehyde was discovered to be toxic in the early 20th century; people started removing formaldehyde from many products that contained the chemical byproducts of it such as formic acid and formaldehyde-releasing resins.

In conclusions, formaldehyde used in embalming is used to preserve dead bodies because it is a good preservative, but it also has many other uses. It has many other uses such as a disinfectant, bactericidal, antiseptic and fixative for tissue and cell samples. These different uses of formaldehyde make it a very useful compound in the body of science.