Ingredient review
CI 12370
INCI: CI 12370
CI 12370 is a synthetic red dye that adds vibrant color to cosmetics, but it offers no skincare benefits and may cause allergic reactions in sensitive individuals.
In plain English
CI 12370 is a man-made red pigment used to give color to makeup and other beauty products. It doesn't treat or improve your skin—it's purely for appearance. While generally safe in the tiny amounts used, some people with very sensitive skin or allergies may experience irritation.
Review score
Safety, usefulness, and evidence
Useful in the right context, but not low-maintenance
The evidence base is useful, but some claims depend heavily on the formula.
Risk flags are low for most users, though the finished product can still irritate.
- Source
- synthetic
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Read the cautions before using
CI 12370 is generally a lower-concern ingredient when the full formula suits your skin.
Plain-English read
Treat this as a practical screening step before you compare products that contain this ingredient.
- Step 1Start with the score, then check the irritation and clogging risk before judging CI 12370.
- Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
- Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.
Score terms in plain English
Irritation risk
lowLess likely to sting, burn, or bother most users, though sensitive skin can still react.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
moderateThere is useful support, but formula details and claim strength still matter.
What it is
CI 12370 is a synthetic azo dye, specifically Acid Red 73, approved for use in cosmetics in many regions. It belongs to a class of colorants that are chemically produced and not derived from natural sources.
How it works
In a cosmetic product, CI 12370 works by absorbing and reflecting certain wavelengths of light, creating a red color. It is mixed into the product base (like a lipstick or blush) to give it a consistent, appealing shade.
Pros
Vibrant color payoff
CI 12370 delivers a strong, consistent red shade that stays true in various product formulations, from lipsticks to nail polishes.
Cost-effective for brands
As a synthetic dye, it is inexpensive to produce, which helps keep the final product affordable for consumers.
Cons and cautions
No skin benefits
This ingredient is purely cosmetic—it adds color but does not moisturize, protect, or improve skin health in any way.
Allergy risk
Azo dyes like CI 12370 can cause contact dermatitis or allergic reactions in some people, especially those with sensitive skin or a history of dye allergies.
Best for
- Anyone looking for a bold red color in makeup
- People without known sensitivities to synthetic dyes
Use caution if
- Individuals with known allergies to azo dyes or sensitive skin prone to reactions
Usage tips
Safety summary
CI 12370 is generally considered safe for cosmetic use at low concentrations, but it can be an allergen for some individuals. Regulatory bodies have set limits to minimize risk, and no major safety concerns have been identified for the general population.
Research notes
Research on CI 12370 focuses on its potential as a contact allergen. Studies show that azo dyes, including Acid Red 73, can cause allergic reactions in susceptible individuals, but the incidence is low in the general population. No significant toxicity or carcinogenicity has been reported at cosmetic use levels.
Common label clues
- Typical concentration
- Typically used at very low concentrations, often below 1%
- Regulatory status
- Approved for use in cosmetics in the EU, US, and many other regions, subject to concentration limits and purity requirements. Always check local regulations as they may vary.
- Common uses
- Lipsticks, Blushes, Nail polishes, Hair dyes, Bath products
- Environmental note
- Synthetic azo dyes can persist in the environment and may require careful wastewater treatment to prevent water pollution.
Good to know
- CI 12370 is also known as Acid Red 73 and is used in some countries as a food dye, though cosmetic use is more common.
- In the European Union, CI 12370 is regulated under Annex IV of the Cosmetics Regulation and is considered safe at authorized concentrations.
Common questions
What is CI 12370 in beauty products?
CI 12370 is a man-made red pigment used to give color to makeup and other beauty products. It doesn't treat or improve your skin—it's purely for appearance. While generally safe in the tiny amounts used, some people with very sensitive skin or allergies may experience irritation.
What does CI 12370 do in a beauty product?
In a cosmetic product, CI 12370 works by absorbing and reflecting certain wavelengths of light, creating a red color. It is mixed into the product base (like a lipstick or blush) to give it a consistent, appealing shade.
Is CI 12370 safe for most people?
CI 12370 is generally considered safe for cosmetic use at low concentrations, but it can be an allergen for some individuals. Regulatory bodies have set limits to minimize risk, and no major safety concerns have been identified for the general population.
Who should be careful with CI 12370?
Individuals with known allergies to azo dyes or sensitive skin prone to reactions
Research sources
Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.