Information about pigments we use in P.C. everyday.  by Linda H. Dixon, MD

Inorganic Pigments Iron oxides (Fe2O3 and Fe3O4) lack a carbon molecule and are therefore "inorganic". Iron oxides in nature (dirt) are often combined with toxic metals like lead, arsenic, mercury, antimony and selenium. The FDA has regulated cosmetic colorants so the level of toxic metal present are below certain percentages in order to be used safely.

Synthetic iron oxides are manufactured to eliminate the contamination of naturally occurring iron oxides. These metals are basically inert, although iron oxide blacks (magnetite) do have magnetic properties. Iron oxides are a softer metal than titanium dioxide.Iron oxide molecules are crystals and are in different shapes. Some are spherical, others are rhomboids and yet others look like a pencil shaped crystal (long and narrow). Ultraviolet light can affect the crystalline structure and result in loss of color activity. Light fastness or "reflectance" describes a particle's ability to reflect light at a certain wavelength. Most synthetic iron oxides are manufactured in the visible light spectrum and have maintain good reflectance. Examples of the endurance of iron oxides are the cave paintings which have endured thousands of years in darkness.

Particle Size

It is a mistaken belief that pigment particles are 6 microns or greater. The fact is that the average iron oxide particle size is less than one micron. However, the particles are attracted to each other and form "agglomerates". When the particles are measured in a suspension it is common to get a particle size measurement of 1-20 microns because the agglomerates are being measured in addition to the individual particles. Although iron oxides are inorganic, they are often dispersed
in glycerin or alcohol which are organic substances.

Carbon Black

Common in inks used for tattooing, the carbon black particle is without shape or "amorphous" and the size is a tiny .03 microns. This means it is from 10-20 timessmaller in size than an iron oxide pigment particle. My personal belief is that this ultra-small size is why we will often see migration or "bleeding" of pigment into surrounding tissues when using carbon black based inks.

An example of carbon black ink is HIGGINS India Ink. Because lead is no longer legal in the U.S. as an additive to carbon black, even India Ink or Pelikan Ink have lost their "black blackness". Carbon black is illegal for use in cosmetics in the United States because of a case of blindness that resulted from its use in mascara. Carbon black is legal in other countries, and is used widely in the US by tattooists. Although it is safe to use when alcohol is present to prevent infections, the law remains to be changed in the U.S.

Solubility

By definition, a pigment is a particle and NOT soluble in solution. If a colorant dissolves in solution then it becomes a dye. Various dispersal agents such as glycerin, ethyl alcohol, Witch Hazel, water, castor oil, propylene glycol and others are used to keep the particles from forming clumps.Remember that these particles are weakly attracted to each other.

Organic

Many colorant molecules are organic because they contain a carbon molecule. You don't have to look any further than your dinner table to find examples of organic
colors. Spinach, carrots, tomatoes, beets and parsley are all "organic" colors. We eat these products every day and they are very safe. Rarely organic colors such as "coal tar" have been determined to have undesirable effects including causing cancer. But this is an exception. Therefore, whether a color is organic or inorganic does not determine the safety of that color. One manufacturer feels strongly FOR organic pigments and yet another feels strongly FOR iron oxides. Just remember that "bright" colors are organic in origin and earth colors are inorganic. Carmine is a naturally occurring red pigment from cochineal extract (beetles)in South America. It is added to some iron oxide pigment lip colors. KolorSource™ pigments use KOSHER glycerin or propylene glycol for peace of mind.

Properties of pigments

The smaller a pigment becomes the more translucent it becomes. This is true of even the most opaque pigment, titanium dioxide. Science is making "nano particles" which are a thousand times smaller than "micronsized" particles. The larger the particle size the more light it will reflect and the more opaque it will become.

Adverse Effects

Iron oxides contain nickel and a large percentage of the population tested is allergic to nickel (17.9%). Tattoo needles,including surgical grade stainless steel needles, contain nickel (8.2%). So sensitivity to pigments can and does occur, even to iron oxides. The fact that organic colorants do not contain nickel is good. However, the inert iron oxides are very safe despite the presence of nickel. Organic pigments can cause severe allergic reactions and granulomas that are difficult to treat. Fortunately, this is rare. Most adverse effects come from sensitivity to antibiotic ointments applied after the permanent cosmetic procedure.

Iron Oxide Colors

In nature, iron oxides exist in reds, yellows, blacks, ochre, umbre and burnt umber. Synthetic iron oxides come in several shades of red, yellow and black. A pigment has both a "top tone" and an "undertone". So in addition to dealing with the undertones in the client's skin, you must take into account the "undertone" in the pigment.

Titanium Dioxide

Compared to iron oxides, titanium dioxide is very opaque. However, although white in appearance, it also has undertones (DuPont) which may be blue on the light spectrum in some cases. It is often mixed with blacks,
reds and yellows to lighten (tint) the original hue (color) of the cosmetic color.

Loss of color over time

a) Exposure to sunlight or UV light 
b) Body breaks down foreign bodies when possible and eliminates them
c) Use of glycolics, Retin-A and other new products for wrinkle treatments are having an adverse effect on permanent makeup.

There are advantages to either inorganic or organic colorants   Allergic reactions to red pigments used in tattoos were actually allergic reactions to the Yellow "Cadmium sulfide" added to the reds. Often times a claim of an "allergic reaction" is made after lip color when in fact the culprit was from overworking the lips with the needles. Bumps will occur in this case. This should NOT be mistakenly diagnosed as an allergic reaction. A tiny tissue “punch” biopsy is needed to confirm ANY suspected allergic reaction. The treatment for allergic reactions ranges from overtattooing with salt water or Kenalog,to topical or systemic steroids to laser removal attempts. Injections of steroids locally usually wear off and the reaction will flare again.

by Linda H. Dixon MD