CHEM 470
Creating Colorful Cosmetics
An introduction to colorants in the personal care industry
I.
II.
Colorants
a. A separate step in the formulation process
b. History
i. Coal, chalk, copper ore, henna, saffron, and other mineral
and plant derivatives to impart color to the body
ii. Few limitations on types of colorants that could be used until
the 20th century
1. toxic metals
2. in 1820 women died from eating pickles colored with
copper sulfate
3. 2 deaths in 1860 from a caterer using copper arsenite
in green pudding
4. Food and Drug Act of 1906 – a list
5. 1938 Food, Drug and Cosmetic Act
a. Certification
6. 1950 several children fell ill after eating popcorn and
candy that contained high levels of color additives
a. Color Additives Amendments of 1960
i. FDA – levels of additives
7. 1959: 116 certifiable colors
8. 1996: 34
9. most scrutinized of the ingredients used in
formulations
Chemical Classification of Colorants
a. Organic or Inorganic
i. Organic originally called “coal tar” or “aniline” colors because
they were derived from coal sources
ii. Synthetics have replaced coal derivatives
1. red, blue, green, yellow, orange, violet
a. organic or water soluble
b. insoluble forms are known as “lake” colorant –
prepared by precipitating a soluble dye on an
insoluble substrate
b. Organic colorants
i. Special nomenclature to replace IUPAC: Ethyl[4-p-[ethyl(msulfobenzyl)amino]-α-(o-sulfo-phenyl)benzylidene]-2,5cyclohexadien-1-ylidene](m-sulfobenzyl)ammonium
hydroxide, disodium salt.
1. US: FD&C Blue No. 1
2. Japan: Blue No. 1
3. EU: C.I.42090
a. Classifications of organic colorants
i. Indigoid group
1. few certifiable dyes like D&C Red
No. 30
ii. Xanthene group
1. acid type (D&C Yellow No. 7)
2. base type (D&C Yellow No. 8)
iii. Azo group
1. large number of certifiable colors
2. includes dyes and pigments
3. sulfonated or unsulfonated
4. D&C Red No. 36
5. D&C Red No. 17
6. D&C Orange No. 4
iv. Nitro group
1. one: Ext. D&C Yellow No. 7
v. Triphentlmethane group
1. sulfonated acid dyestuffs
2. FD&C Blue No. 1
3. FD&C Green No. 3
vi. Quinoline group
1. two certified colorants
2. D&C Yellow No. 11
3. D&C Yellow No. 10
a. Good light stability
vii. Anthraquinone group
1. sulfonated acid dyes
2. unsulfonated anthraquinones and
hydroxyanthraquinones
3. D&C Green No. 6
4. D&C Violet No. 2
c. Inorganic colorants
i. Iron oxides
1. synthetic
2. yellow hydrated iron oxide (ochre)
3. brown, red, black iron oxides
ii. Carbon blacks
1. black pigments
a. mascara
2. produced from carbon deposits burned onto an iron
surface with a natural gas flame (not approved in the
US)
iii. Chromium oxide greens
1. Cr2O3 purified by acid washings
iv. Ultramarines
III.
IV.
V.
1. fire process using sulfur, soda ash, china clay and
charcoal pitch
a. pink and blue colors available
v. Manganese and Ferric ferrocyanides
vi. Not water soluble
d. Natural sources
i. Caramel coloring, carrot oil, beet extract, henna, fruit and
vegetable extracts
Selecting Colorants
a. Most cosmetics have colorants added to them
b. Factors determining colorant choice: regulatory status, physical
and chemical properties of the formula, chemical stability of the
colorant, shade desired
c. Type of product: Where on the body will the product be used?
i. Shampoos, conditioners, skin lotions (do not come in contact
with mucous membranes) – FD&C, D&C or Ext. D&C
ii. Eyeshadow, mascara – can use only inorganics and natural
sources – FD&C and special D&C
1. silver, henna, lead acetate and bismuth citrate are not
certified for use in this area
2. level limits
d. Formulation requirements: physical and chemical properties
i. Aqueous? FD&C and D&C
ii. Solid? Inorganics
iii. Non-aqueous solution? Alcohol-soluble colorants
iv. Physical and chemical properties
1. exposure to light or heat
2. high or low pH
3. concentration
4. incompatible ingredients
5. contamination with microorganisms
Shades
a. Fashion trends – make-up
b. Cost: minor consideration
i. Small quantities
ii. Exception: products with high pigment load such as lipstick
and eyeshadow
Batching with Colorants
a. Colorants supplied in concentrated powder form
b. Use very little
i. Color in shampoo, e.g., 0.00001% dye
ii. Use dilute stock solutions 0.1 wt%)of water soluble dyes
iii. Larger scale weighs out solid, dissolved in water and then
added to the large batch
c. Powders: eyeshadow and blush require special processing
i. Dispersion
VI.
1. grinding or milling
a. hammer mill and the ball mill
b. pulverizes pigment particles and intermingles
them with talc and other powdered ingredients
c. creates a fine dispersion with allows the true
color to shine through
2. roller mill
a. disperses powder through an oil- or wax-based
product
Future of colorants
a. Modern analytical techniques
i. Detect extremely low levels of contaminants – health affects
1. be prepared to pose an alternative
Table 1. Certifiable Color Definitions for U.S.
Colorant Type
Food, Drug and Cosmetic (FD&C)
Drug & Cosmetic (D&C)
External Drug and Cosmetic (Ext.
D&C)
Definition
Certifiable colors that are for use in
coloring food, drugs and cosmetics
Certifiable colors that are for use in
coloring drugs and cosmetics including
those in contact with mucous
membranes and those that are
ingested
Certifiable colors that are for use in
coloring drugs and cosmetics that do
not come in contact with mucous
membranes or those that are ingested
Table 2. Examples of Inorganic colorants and other materials not requiring
certification
Material
Aluminum powder
Annatto
Bronze powder
Chromium hydroxide
green
Ferric ferrowcyanide
Manganese violet
Ultramarines
Zinc oxide
CI Number
77000
75120
77400
77289
CFR Reference
73.2645
73.2030
73.2646
73.2326
77510
77742
77007
77947
73.2299
73.2775
73.2725
73.2991