What is red 30 dye made of? Unveiling the Chemical Origins

January 11, 2026 •

3 min read

According to the U.S. Food and Drug Administration (FDA), D&C Red No. 30 is a certified color additive approved for use in drugs and cosmetics. But what is red 30 dye made of? This vibrant pigment is a synthetic chemical compound, a fact that often surprises consumers accustomed to natural dyes.

Quick Summary

Red 30 dye is a synthetic pigment derived from petroleum or coal tar sources, known chemically as a thioindigo colorant or CI 73360. It is primarily used to impart a deep pink or reddish hue to cosmetics and personal care products after FDA certification. Its insoluble nature makes it an effective and stable pigment.

Key Points

Synthetic Origin: Red 30 dye is synthetically produced from petrochemical sources, including petroleum or coal tar.
Chemical Name: The official chemical name is 6-chloro-2-(6-chloro-4-methyl-3-oxobenzo[b]thien-2(3H)-ylidene)-4-methyl-benzo[b]thiophen-3(2H)-one.
Thioindigo Class: It belongs to the thioindigo class of colorants, prized for their excellent stability to heat and light.
Pure vs. Lake Form: It is available as a pure, water-soluble dye and a water-insoluble 'lake' form, which is precipitated with a metallic salt like aluminum.
Cosmetic and Drug Use: Red 30 is FDA-approved for use specifically in drugs and cosmetics, not for food.
Applications: It provides a deep pink to reddish color in products such as lipsticks, blushers, and nail polishes.

The Chemical Identity of Red 30 Dye

D&C Red No. 30, known also by its Colour Index (CI) number CI 73360, is a synthetic substance with a specific chemical structure. It can exist as a pure dye or as 'lakes,' which are formed by precipitating the water-soluble dye with a metallic salt, such as aluminum, rendering it insoluble. The primary chemical identification for Red 30 is 6-chloro-2-(6-chloro-4-methyl-3-oxobenzo[b]thien-2(3H)-ylidene)-4-methyl-benzo[b]thiophen-3(2H)-one. This chemical descriptor signifies its synthetic origin, differing from natural colorants. Red 30 is categorized as a thioindigo colorant, a group of pigments recognized for their stability in the presence of light and heat.

Raw Materials and Synthesis

The creation of red 30 dye relies on petrochemicals, with primary sources being petroleum or coal tar. These materials undergo a chemical synthesis process to achieve the final pigment. The resulting fine powder is typically certified by regulatory bodies, like the FDA, before it can be incorporated into consumer goods.

The Difference Between D&C Red No. 30 and its 'Lake' Form

Manufacturers often use D&C Red No. 30 in two forms: the pure dye and its lake version. This distinction is important for its application in different products.


Feature	D&C Red No. 30 (Pure Dye)	D&C Red No. 30 Lake
Solubility	Soluble in water.	Insoluble in water.
Composition	Pure organic pigment, CI 73360.	Water-soluble dye adsorbed onto a metallic salt (e.g., aluminum).
Certification	Batch certified by the FDA.	Requires batch certification.
Best For	Products where dissolution is possible.	Products needing an insoluble pigment like powders or lipsticks.
Stability	Excellent stability to light and heat.	Excellent stability to light and heat.

Applications in Consumer Products

Red 30 dye's stability and pinkish-red color make it suitable for numerous consumer products. Its usage is strictly regulated by bodies like the FDA, specifically for quantity and application. It is only approved for drugs and cosmetics, not food.

Makeup: Used in items like blushers, lipsticks, and eye shadows.
Nail Products: Found in nail polishes.
Personal Care Products: Included in bath products.
Pharmaceuticals: Used for coloring certain drugs.

Red 30 vs. Other Red Dyes

Red 30 is distinct from other red dyes with different compositions and regulations. For example, FD&C Red No. 3 is an organoiodine compound, and its food and ingested drug approval has been revoked by the FDA. FD&C Red No. 40 is an azo dye, chemically different from Red 30's thioindigo structure. Red 30's specific chemical identity defines its role and regulation in cosmetics and drugs.

Conclusion

To summarize, Red 30 dye is a synthetic thioindigoid colorant derived primarily from petrochemical sources such as petroleum or coal tar. Its chemical structure makes it a stable pigment used widely in cosmetics, personal care products, and pharmaceuticals. The distinction between the pure, water-soluble dye and its water-insoluble 'lake' form is important for understanding its varied uses. Although its origins are synthetic, its application is carefully regulated to ensure consumer safety within approved uses. Understanding the chemical nature of ingredients like Red 30 clarifies the composition of everyday products. Further details on its regulatory status can be found through the FDA's color additives information.

Frequently Asked Questions

Chemically, Red 30 dye is a complex synthetic compound classified as a thioindigo colorant, with the chemical name 6-chloro-2-(6-chloro-4-methyl-3-oxobenzo[b]thien-2(3H)-ylidene)-4-methyl-benzo[b]thiophen-3(2H)-one.

No, Red 30 dye is not a natural ingredient. It is a synthetic pigment derived from petrochemicals, specifically petroleum or coal tar.

Red 30 is the pure, water-soluble synthetic dye. Red 30 Lake is the water-insoluble version, created by precipitating the dye with a metallic salt, which makes it suitable for use in products like powders and lipsticks.

Red 30 dye is commonly used in cosmetics and personal care products like lipsticks, blushers, face powders, nail polishes, and some pharmaceuticals.

Yes, in the United States, Red 30 dye is regulated by the FDA. Each batch must be certified by the agency to ensure it meets strict purity and composition standards.

While Red 30 is approved for drugs and cosmetics, it is not approved for use in food. This is in contrast to other red dyes, like Red 40, which have different chemical compositions and regulatory approval for ingestible products.

No, Red 30 is a synthetic dye derived from petrochemicals. Other red dyes, such as carmine (Red 4), are derived from cochineal insects, which is a different substance entirely.