Ingredient review
CI 40215
INCI: CI 40215
A widely used synthetic yellow dye that is generally safe in cosmetics but may cause allergic reactions in sensitive individuals.
In plain English
CI 40215 is a synthetic yellow dye, also known as Tartrazine or FD&C Yellow No. 5. It's added to makeup and other beauty products to give them a bright yellow color. While it's approved for use in cosmetics, some people may experience skin irritation or allergic reactions, especially if they have a sensitivity to aspirin or other 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
CI 40215 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 40215.
- 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 40215 is a water-soluble azo dye, meaning it contains a nitrogen-nitrogen double bond that gives it its color. It is produced synthetically from petroleum derivatives.
How it works
In cosmetics, CI 40215 works by absorbing and reflecting specific wavelengths of light, making the product appear yellow. It does not have any active skincare function; its sole purpose is aesthetic.
Pros
Vibrant and stable color
Provides a consistent, bright yellow hue that doesn't fade easily in products.
Cost-effective
Much cheaper than many natural yellow colorants, keeping product prices lower for consumers.
Cons and cautions
Potential allergen
Can cause allergic reactions, including hives or skin irritation, in sensitive individuals, particularly those with aspirin intolerance.
Synthetic origin
Derived from petroleum, which some consumers may wish to avoid for environmental or personal preference reasons.
Best for
- Anyone looking for a vibrant yellow color in their makeup
- Consumers who are not sensitive to synthetic dyes
Use caution if
- Individuals with known allergies to Tartrazine or other azo dyes
- People with aspirin sensitivity or asthma (higher risk of allergic reaction)
Usage tips
Safety summary
Generally recognized as safe for most people when used in cosmetics at low concentrations. However, it can cause allergic reactions in sensitive individuals, particularly those with aspirin sensitivity or asthma.
Research notes
Studies confirm that CI 40215 is a common allergen in patch tests for cosmetic dermatitis, but reactions are relatively rare in the general population. Regulatory bodies worldwide have set safe usage limits.
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 by the FDA (USA) and the European Commission (EU), with specific concentration limits and labeling requirements in some regions.
- Common uses
- Eyeshadows, Lipsticks, Blushes, Nail polishes, Hair dyes
- Environmental note
- As a synthetic dye, it is not biodegradable and may accumulate in waterways. Some manufacturers are moving toward natural alternatives to reduce environmental impact.
Good to know
- CI 40215 is the same as FD&C Yellow No. 5, which is also used in food and drugs.
- In the EU, it must be labeled with a warning about potential adverse reactions in sensitive individuals.
- It is not a skincare active ingredient—it only provides color.
Common questions
What is CI 40215 in beauty products?
CI 40215 is a synthetic yellow dye, also known as Tartrazine or FD&C Yellow No. 5. It's added to makeup and other beauty products to give them a bright yellow color. While it's approved for use in cosmetics, some people may experience skin irritation or allergic reactions, especially if they have a sensitivity to aspirin or other dyes.
What does CI 40215 do in a beauty product?
In cosmetics, CI 40215 works by absorbing and reflecting specific wavelengths of light, making the product appear yellow. It does not have any active skincare function; its sole purpose is aesthetic.
Is CI 40215 safe for most people?
Generally recognized as safe for most people when used in cosmetics at low concentrations. However, it can cause allergic reactions in sensitive individuals, particularly those with aspirin sensitivity or asthma.
Who should be careful with CI 40215?
Individuals with known allergies to Tartrazine or other azo dyes People with aspirin sensitivity or asthma (higher risk of allergic reaction)
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.