(14) Embalming Chemicals

There are 8 types of chemicals found in formulations…

Preservatives, disinfectants, anticoagulants, surfactants, dyes, perfuming agents and vehicles

Arterial fluid

Embalming, vascular or preservatice fluid. Concentrated fluid poured into the tnak to which other chemicals are added (water corrective, modifiers, etc)

Arterial solution

Embalming solution or primary dilution. This is what is in the tank and used for injeciton into the body

Cavity fluid

Concentrated fluid formulated for injection into the cavity after aspiration. Other uses include hypo injection and surface compresses

Accessory Chemicals

Surface gels and the like

Arterial fluid can include…

Vehicles, modifying agents, dyes, surfactant, perfuming agents, germicide, anticoagulants, preservative

HCHO

Most common preservative. CH3OH, methyl alcohol, methanol is added as an antipolymerant.

What are preservatives?

Class of chemicals that react with protein to denature or coagulate them so they are no longer subject to putrefaction or decomp

What are some examples of preservatives?

Formaldehyde, phenols, glyoxal, glutaraldehyde, paraformaldehyde

What is formalin?

HCHO in an aqueous solution of 37% HCHO by mass and 40% by volume. DContains 7% methyl alcohol and the remainder water

What happens to formalin above 50%?d

Becomes unstable and subject to polymerization (precipitation)

Index

amount of pure HCHO gas in grams per 100mL of water. 25 index fluid should have 25g of HCHO in 100 mL of waer.

What are the disadvantages of HCHO?

-Rapidly coagulates blood
-Grays the body
pConstricts capillaries
-Dehydrates tissues
-Deteriorates with age
-Irritating to the embalmer and a suspected carcinogen

What are the advantages of HCHO?

-Inexpensive production
-Inhibits mold and yeast growth
-Bactericidal
-Rapidly destroys autolytic enzymes
-Rapidly acts on proteins making them resistant to decomp
-Firms tissues to make positioning easier
-Small amount needed to preserve

WHat is paraformaldehyde?

-Polymer of HCHO
-95% in strength
-used for dusting sidewalls and cavity treatment in autopsied cases
-Can be seen in old bottles of arterial solution as white flakes at the bottom

What is trioxane?

Another polymer of HCHO that is smaller and has an odor similar to chloroform. Expensive so llimited in its use.

What is the simplest dialdehyde?

Glyoxal
avaliable as 30% yellowish aqueous solution

Why is glyoxal limited to cavity formulas?

Tends to stain tissue yellow

WHat is phenol?

Carbolic acid. very common in the early days of arterial and cavtiy fluids. Readily penetrates the skin and tissue. Absorbed rapidly by protein structures. turns skin putty gray as a result used mainly in cavity fluids. Can also be used as a blaching agent, surface pack, cauterizing and tissue reduction

What are germicides?

Fluids incorporated into arterial fluids, cavity fluids and surface disinfectants. Most preservative chemicals are germicidal. Quaternary ammonium compounds are good disinfectatns

Buffers

keep the solution and tissues around 7.2-7.4 (slightly alkaline)
Body pH varies at different points post mortem

What buffers are used as anticoagulants?

Borates, carbonates, citrates, phosphates, salts of EDTA

Carbonates

Sodium carbonate, magnesium carbonate have about the same purposes as borates but are not as effective at stabilizing HCHO over long periods

Borates

borax, sodium borate, good stabilizer of formalin providing a degree of alkalinity. Reduces the graying actions of HCHO. Properly formulated borates have extended the shelf life of embalming fluids more than 2 years

HUmectants

Described as having a coating action on the HCHO molecules which keep it from reacting with the protein until the tissues are saturated. Will cause HCHO to release at a slower rate. They cause the tissue to have a rubbery flexible feel. Also known asa plasticizing agents

What are some humectants?

Glycerine, sorbitol, glycols, polyhydroxy alcohols

Glycerine

Glycerol, 3 carbon atoms to which 3 hydroxyl (alcohol) functional groups are attached. Increases the germicidal qualities of other chemicals (while not being a germicide itself) owing to the fact that it is an excellent solvent for disinfectants. Hygroscopic.

Sorbitols

6 carbon atoms to which 6 hydroxyl (alcohol) groups are attached. greater affinitiy for water. Loses water at slower rate than glycerine. Precipitates out at low temperatures is a disadvantage

What are glycols?

Particularly ethylene, propylene and diethylene glycol are used as humectants. theya re completely soluble in water. Superior solvents compared to glycerine. Propylene glycol is used as mold inhibitor

What are emulsified oils?

Emollient quality. They are not water soluble themselves but can be dispersed into aqueous solutions

Examples of emulsified oils

Lanolin, silicon, oils of palmitate and oils of oleate

Gums

-Used in restorative type humectants or bodies that need to be held for a time. They can take up space in capillaries and swell when they come in contact with moisture
-Important to have all the blood out prior to use since they will get trapped in the capillaries
-Can be vegetable or synthetic

What do inorganic salts do?

-Can control osmotic qualities
-be used in special purpose fluids to draw moisture out of tissue (ex: edema eliminators)

What do anticoagulants do?

-Maintain blood in liquid state
-Make it easier to displace blood
-Stops the clotting process and softens clots so that they break up into smaller ones (does not liquify existing clots)
-Reduces hardness of water

Why is an anticoagulant’s ability to provide alkalinity so important?

-Allows dues to work (reduces blotching)
-Allows HCHO to work

Oxalates

early type of anticoagulant. Not used due to toxicity

Citrates

Used as water conditioner as well as anticoagulant

Stabilizer for HCHO that also serves as an anticoagulant. Sodium borate, borax and sodium tetraborate

Borates

EDTA (ethylenediaminetetraacetic acid)(sodium salt)

Chelating agent and not found in arterial fluid as they are incompatible over the long shelf life

Epsom salts

Can be used as an edema eliminator- magnesium sulfate is also used

Wetting agents

Agents that reduce surface tension or capillary attraction. They allow fluid to enter the cells and tissues easier.

Cells are surrounded by a thin film of mostly water- what embalming chemical can break that film?

Surfactants

In order for surfactants to be effective, what must be true?

-Must be well balanced
-Must be at correct temperature; warm water will reduce it’s surface tension and speed up firming

How do surfactants increase germicidal qualities?

They allow the chemical to penetrate

Anionic surfactants

Soap, alkul sulfonates, alkyl aryl sulfonates, salts of thioalchols and oils

Cationic surfactants

-Quaternary ammonium (neutralized by soaps)
-Al, Mg and Ca (cause precipitation)

Active dyes…

stain tissue and impart color

Inactive dyes…

lends color in the bottle and does not stain the tissue

What are some examples of natural coloring agents?

Cudbear, carmine and cochineal

What are some synthetic coloring agents?

Eosin, erythrosine, ponceau, amaranth

Dyes can mix powders with…

water corrective

What do perfuming agents do?

mask the odor of the preservative but do not eliminate nor change it

What are the esters that are used as perfuming agents?

Cinnamon, cloves, fruits, oil of wintergreen (methyl salicylate)

What are vehicles?

Compound used to deliver or carry preservative. Usually water

What other vehicles can be used in addition to water?

Sorbitol, glyverine and alcohols