Ingredient review
CI 45430
INCI: CI 45430
CI 45430 is a common synthetic red dye that adds vibrant color to cosmetics, but it has some safety concerns, particularly regarding oral ingestion.
In plain English
CI 45430, also known as Red 3 or Erythrosine, is a man-made dye that gives a bright cherry-red color to makeup and personal care products. It's widely used in lipsticks, blushes, and other color cosmetics. While it's generally considered safe for topical use on skin, there are some concerns about its safety when ingested, which is why it's banned in some countries for use in food but still allowed in cosmetics in the US and elsewhere.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
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
Useful, but context matters
CI 45430 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 45430.
- 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 45430 is a synthetic organic dye derived from petroleum. It belongs to the xanthene class of dyes and is produced through a chemical process that creates a bright red powder. In cosmetics, it's used to impart color to products and is listed on ingredient labels by its Color Index number.
How it works
In a cosmetic product, CI 45430 works by absorbing and reflecting specific wavelengths of light, which creates the perception of a red color. It is mixed into the product base (like a lipstick or blush formula) to evenly distribute the color. The dye is stable under normal use conditions and does not chemically react with the skin.
Pros
Vibrant color payoff
CI 45430 delivers a bright, consistent red shade that stays true on the skin, making it a favorite for bold lipsticks and blushes.
Stable and long-lasting
This dye is chemically stable in most cosmetic formulations, meaning the color won't easily fade or change over time.
Cons and cautions
Ingestion safety concerns
Studies have linked high doses of CI 45430 to thyroid tumors in animals, leading to its ban in food in some regions. While topical use is considered safe, this raises caution for lip products that may be ingested.
Potential allergen
A small percentage of people may experience skin irritation or allergic reactions, such as redness or itching, when using products containing this dye.
Best for
- Anyone looking for a bright red color in their makeup
- People who are not sensitive to synthetic dyes
Use caution if
- Individuals with known allergies to synthetic dyes
- Those who prefer to avoid petroleum-derived ingredients
Usage tips
Safety summary
CI 45430 is generally considered safe for topical cosmetic use at low concentrations. However, ingestion concerns from animal studies mean it is best avoided in lip products for those who are cautious. Allergic reactions are rare but possible.
Research notes
Research on CI 45430 primarily focuses on its oral toxicity, with animal studies showing a link to thyroid tumors at high doses. Topical safety data is limited but suggests low risk. The Cosmetic Ingredient Review (CIR) panel has deemed it safe for use in cosmetics under current practices.
Common label clues
- Typical concentration
- Typically used at very low concentrations, often less than 1%
- Regulatory status
- Approved for use in cosmetics in the US by the FDA, but banned in food in the EU and other regions. Always check local regulations.
- Common uses
- Lipsticks, Blushes, Eye shadows, Nail polishes
- Environmental note
- As a synthetic dye derived from petroleum, CI 45430 is not biodegradable and may contribute to environmental pollution if not properly disposed of.
Good to know
- CI 45430 is also used in some food products in the US, but it is banned in food in the European Union and several other countries.
- In cosmetics, it is often combined with other dyes to create custom shades.
Common questions
What is CI 45430 in beauty products?
CI 45430, also known as Red 3 or Erythrosine, is a man-made dye that gives a bright cherry-red color to makeup and personal care products. It's widely used in lipsticks, blushes, and other color cosmetics. While it's generally considered safe for topical use on skin, there are some concerns about its safety when ingested, which is why it's banned in some countries for use in food but still allowed in cosmetics in the US and elsewhere.
What does CI 45430 do in a beauty product?
In a cosmetic product, CI 45430 works by absorbing and reflecting specific wavelengths of light, which creates the perception of a red color. It is mixed into the product base (like a lipstick or blush formula) to evenly distribute the color. The dye is stable under normal use conditions and does not chemically react with the skin.
Is CI 45430 safe for most people?
CI 45430 is generally considered safe for topical cosmetic use at low concentrations. However, ingestion concerns from animal studies mean it is best avoided in lip products for those who are cautious. Allergic reactions are rare but possible.
Who should be careful with CI 45430?
Individuals with known allergies to synthetic dyes Those who prefer to avoid petroleum-derived ingredients
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.