Ingredient review
Acid Red 27
INCI: CI 18736
CI 18736 is a common synthetic red dye that adds color to cosmetics but has limited skincare benefits and may cause allergic reactions in sensitive individuals.
In plain English
CI 18736 is a man-made red dye that gives a red or pink color to makeup and other beauty products. It doesn't do anything for your skin except change its appearance. Some people may find it irritating, especially if they have sensitive skin or allergies to certain dyes.
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
Acid Red 27 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 Acid Red 27.
- 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 18736 is a synthetic azo dye, specifically a red colorant approved for use in cosmetics in many regions. It is also known as Acid Red 27 or FD&C Red No. 2.
How it works
In a cosmetic product, CI 18736 simply absorbs and reflects light in the red spectrum, giving the product a red or pink hue. It does not interact with the skin or provide any functional benefit beyond coloring.
Pros
Vibrant color
Provides a bright, consistent red or pink shade that is stable in many cosmetic formulations.
Widely available
Commonly used in many makeup products, making it easy to find in a variety of items.
Cons and cautions
No skin benefit
CI 18736 is purely a colorant and offers no moisturizing, anti-aging, or protective benefits for the skin.
Allergic potential
Some people may experience skin irritation or allergic reactions, especially those with sensitive skin or dye allergies.
Best for
- Anyone looking for a red or pink tint in their makeup
- People without known sensitivities to synthetic dyes
Use caution if
- Individuals with known allergies or sensitivities to azo dyes or synthetic colorants
Usage tips
Safety summary
CI 18736 is generally considered safe for use in cosmetics at regulated concentrations, but it can cause allergic reactions in sensitive individuals. It is not a skincare active and offers no therapeutic benefits.
Research notes
Research indicates that CI 18736 is a common allergen in patch tests for some populations, but adverse reactions are rare. It is not classified as a carcinogen or reproductive toxin at cosmetic use levels.
Common label clues
- Typical concentration
- Typically used at very low concentrations (less than 1%) to achieve desired color.
- Regulatory status
- Approved for use in cosmetics in the EU, US, and many other countries, but subject to concentration limits and purity requirements. Not approved for use in food in some regions.
- Common uses
- Lipsticks, Blushes, Nail polishes, Hair dyes, Soaps
- Environmental note
- As a synthetic dye, CI 18736 may not be biodegradable and can contribute to water pollution if not properly filtered during manufacturing.
Good to know
- CI 18736 is banned in some countries for use in food but is still permitted in cosmetics in many regions.
- It is often listed simply as 'CI 18736' or 'Acid Red 27' on labels.
Common questions
What is Acid Red 27 in beauty products?
CI 18736 is a man-made red dye that gives a red or pink color to makeup and other beauty products. It doesn't do anything for your skin except change its appearance. Some people may find it irritating, especially if they have sensitive skin or allergies to certain dyes.
What does Acid Red 27 do in a beauty product?
In a cosmetic product, CI 18736 simply absorbs and reflects light in the red spectrum, giving the product a red or pink hue. It does not interact with the skin or provide any functional benefit beyond coloring.
Is Acid Red 27 safe for most people?
CI 18736 is generally considered safe for use in cosmetics at regulated concentrations, but it can cause allergic reactions in sensitive individuals. It is not a skincare active and offers no therapeutic benefits.
Who should be careful with Acid Red 27?
Individuals with known allergies or sensitivities to azo dyes or synthetic colorants
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.