Red 33 is approved for use on skin in the United States and is considered safe at the concentrations found in cosmetics and topical drugs. The FDA permanently listed it in 1988 for externally applied cosmetics and drugs, with one notable restriction: it cannot be used in products applied around the eyes.
What Red 33 Is and Where You’ll Find It
Red 33 is a synthetic azo dye that gives products a vivid pink-to-red color. You’ll spot it on ingredient labels under several names: D&C Red No. 33, CI 17200, Acid Red 33, or azofuchsine. It shows up in lipsticks, blushes, body washes, shampoos, mouthwashes, and toothpastes. In lip products specifically, it’s capped at 3% by weight of the finished product.
How the FDA Regulates It
Unlike many cosmetic ingredients that manufacturers can use without pre-approval, color additives in the U.S. must be explicitly approved by the FDA and each batch must be certified before it reaches consumers. Red 33 earned its permanent listing for cosmetic and drug use in 1988, meaning it passed the agency’s safety review for those applications.
The approval comes with clear boundaries. Red 33 is permitted in externally applied cosmetics (including lip products), mouthwashes, toothpastes, and topical drugs. It is not approved for use in the eye area, in injectable products, or in surgical materials. For ingested drugs other than mouthwashes and toothpastes, the limit drops to just 0.75 milligrams per daily dose.
How Much Actually Penetrates Your Skin
One of the biggest safety questions with any cosmetic dye is whether it passes through the skin and enters the bloodstream. Research on similar azo dyes suggests the answer, for Red 33, is essentially no. A dermal absorption study using a related cosmetic colorant with comparable molecular properties found that in a cream formulation, 0% of the applied dye penetrated into or through the skin. In a lotion formulation, only about 3.4% reached the deeper skin layers, and none was detected in the fluid beneath the skin (meaning none reached the bloodstream).
This tracks with what chemists would predict from Red 33’s physical properties. It has a large molecular weight, extremely low fat solubility, and a high melting point. All of these characteristics make it very difficult for the molecule to slip past the skin’s outer barrier. In practical terms, when you apply a product containing Red 33, the dye sits on or near the surface and washes off rather than absorbing into your body.
Skin Irritation and Allergic Reactions
For the vast majority of people, Red 33 does not cause irritation or allergic reactions at the concentrations used in cosmetics. That said, isolated cases of contact sensitization have been documented. In one clinical report, a patient who was already sensitized to other chemicals (specifically a resin used in nail products) also reacted to D&C Red 33 during patch testing. This kind of cross-reactivity is uncommon and tends to occur in people who already have heightened sensitivity to multiple chemical groups.
If you have a history of contact dermatitis from cosmetics or dyes, Red 33 is worth watching for on ingredient labels. But for most people, it does not pose an irritation risk at typical use levels. No widespread pattern of allergic reactions has prompted regulatory action or label warnings beyond the existing use restrictions.
Purity and Contaminant Limits
Because each batch of Red 33 must be certified before sale, the FDA enforces strict purity standards. Lead contamination cannot exceed 20 parts per million (0.002%). Arsenic is limited to 2 parts per million. Other heavy metals collectively cannot exceed 30 parts per million. These thresholds are low enough that trace contaminants in certified batches do not pose a meaningful health risk through skin contact.
This batch certification process is one reason color additives like Red 33 are among the more tightly controlled cosmetic ingredients in the U.S. regulatory system. Every production run is tested before it can legally be used in a consumer product.
The Eye Area Exception
The one place you should not use products containing Red 33 is around your eyes. The FDA’s permanent listing explicitly excludes eye-area application. The mucous membranes and thinner skin around the eyes absorb substances more readily than skin elsewhere on the body, and Red 33 has not been evaluated or approved for that level of exposure. If you’re choosing an eyeshadow, eyeliner, or under-eye product, check the ingredient list and look for colorants that carry specific eye-area approval.
How to Identify It on Labels
Red 33 appears under different names depending on the product type and where it’s sold. In U.S. cosmetics, you’ll typically see “D&C Red No. 33” or “D&C Red 33.” Products sold internationally, particularly in Europe, may list it as “CI 17200” or “Acid Red 33.” Less common synonyms include azofuchsine and azo fuchsine. If you’re trying to avoid it or confirm its presence, scanning for any of these names will cover your bases.