How to Read Cosmetic Ingredient Labels: INCI Names, Fragrance and Common Irritants

INCI: the naming system on every label

Most cosmetic labels use INCI names, short for International Nomenclature of Cosmetic Ingredients. The system gives each ingredient one standard name so the same substance is listed the same way regardless of brand or country. That is why you will see sodium laureth sulfate rather than a brand's own name for a cleansing agent.

Some INCI conventions are worth knowing. Plant ingredients are usually listed by their Latin botanical name with the common name in parentheses, such as Butyrospermum Parkii (Shea) Butter. Water often appears as Aqua, particularly on products sold in the EU. Colorants in the EU are listed by Color Index numbers, such as CI 77891 for titanium dioxide.

A long, chemical-sounding name does not mean an ingredient is harsh. Tocopherol is vitamin E, sodium hyaluronate is a form of hyaluronic acid, and cetearyl alcohol is a fatty alcohol that softens skin rather than drying it out like the alcohol in hand sanitizer.

The order of ingredients and the 1% line

In both the US and the EU, cosmetic ingredients present above 1% must be listed in descending order of concentration. Ingredients at 1% or less can be listed in any order after them, and colorants can be grouped at the end.

This means the first five or so ingredients usually make up most of the formula, often with water first. It also means you cannot assume an ingredient near the end is present in a lower amount than the one before it, once you are below 1%.

Labels do not mark where the 1% point falls, but you can sometimes estimate it. Phenoxyethanol, a common preservative, is limited to a maximum of 1% in the EU, so ingredients listed after it are generally present at 1% or less. That is useful when a product advertises an active ingredient that appears near the bottom of the list.

Fragrance, parfum and fragrance allergens

In the US, fragrance can be listed simply as fragrance or parfum, without naming the individual components, which can number in the dozens. This is allowed to protect trade secrets, but it means you cannot tell from the label exactly what a fragrance contains.

Fragrance is one of the most common causes of allergic contact dermatitis from cosmetics. The EU addresses this by requiring specific fragrance allergens, such as linalool, limonene, geraniol and citronellol, to be named on the label when they exceed set concentrations: 0.001% in leave-on products and 0.01% in rinse-off products. The EU expanded that list substantially in 2023, with a transition period for manufacturers.

In the US, the Modernization of Cosmetics Regulation Act of 2022 (MoCRA) directs the FDA to issue rules requiring fragrance allergens to be disclosed on labels. Until those rules take effect, fragrance-free products are the most reliable choice if you react to fragrance. Note that unscented is not the same thing: an unscented product can contain a masking fragrance to cover the smell of other ingredients.

Common irritants and allergens to recognize

Beyond fragrance, a few ingredient groups account for many reactions. Preservatives are one: methylisothiazolinone (MI) is a well-known contact allergen and is restricted in the EU, and formaldehyde-releasing preservatives such as DMDM hydantoin, quaternium-15, imidazolidinyl urea and diazolidinyl urea can trigger reactions in people allergic to formaldehyde.

Others include p-phenylenediamine (PPD) in permanent hair dyes, which is why dye kits tell you to do an allergy test 48 hours before use; lanolin; essential oils such as tea tree and lavender, which contain fragrance compounds; and cleansing agents like sodium lauryl sulfate, which can irritate dry or sensitive skin with frequent use.

Parabens get a lot of attention. The EU banned five less common parabens in 2014 and set limits on others, while methylparaben and ethylparaben remain permitted. They are relatively uncommon causes of allergy on intact skin, so a paraben-free label is not automatically gentler. Ingredients that bother one person may be fine for another, which is why patch testing matters more than any list.

When a cosmetic is regulated as a drug

In the US, some products that look like cosmetics are legally over-the-counter drugs because of what they claim to do. Sunscreens, antiperspirants, anti-dandruff shampoos and acne treatments containing benzoyl peroxide or salicylic acid fall into this group.

These products carry a Drug Facts panel instead of, or alongside, a standard ingredient list. Active ingredients are listed first with their percentage and purpose, such as zinc oxide 10% (sunscreen), followed by inactive ingredients. This is one of the few places on a personal care label where you see exact concentrations.

Marketing terms with no legal definition

Many popular label terms are not defined by US law. Hypoallergenic, dermatologist tested, clean, non-toxic and natural have no federal standard, so companies can use them based on their own criteria. The FDA has stated that there are no federal standards for the term hypoallergenic.

Non-comedogenic, meaning unlikely to clog pores, is also not a regulated term in the US, although some brands test for it. Treat all of these as claims to verify against the ingredient list rather than as guarantees.

MoCRA did add new obligations for cosmetics companies in the US, including registering facilities, listing products with the FDA, reporting serious adverse events and keeping evidence that products are safe. Cosmetics other than color additives still do not need FDA approval before they go on sale.

Worked example: reading a moisturizer label

Here is a typical face moisturizer: Aqua (Water), Glycerin, Caprylic/Capric Triglyceride, Cetearyl Alcohol, Niacinamide, Butyrospermum Parkii (Shea) Butter, Dimethicone, Ceteareth-20, Panthenol, Phenoxyethanol, Tocopherol, Ethylhexylglycerin, Parfum (Fragrance), Linalool, Limonene, CI 77891.

The first four ingredients form the base: water, glycerin (a humectant that draws water into the skin), caprylic/capric triglyceride (an emollient oil derived from coconut or palm) and cetearyl alcohol (a thickener and softener). Niacinamide is fifth, ahead of shea butter and the preservative. Its position suggests a meaningful amount, but the label alone cannot confirm an exact percentage.

Phenoxyethanol marks the approximate 1% line. Everything after it, including tocopherol, the fragrance and the two fragrance allergens, is present at 1% or less. Linalool and limonene are listed separately because they exceed the EU labeling threshold. CI 77891 is titanium dioxide, used here as a whitening pigment.

The verdict: a straightforward moisturizer with useful humectants and emollients. If your skin reacts to fragrance, the parfum, linalool and limonene are the ingredients to note, and a fragrance-free alternative would be a safer choice.

How to patch test a new product

Before using a new product on your face, apply a small amount to a patch of skin such as the inner forearm or behind the ear, once or twice a day, for about a week. Some allergic reactions take several days to appear, so a single try is not enough.

Stop using the product if you notice redness, itching, swelling or a rash. If a reaction is severe, spreads, or involves your eyes, lips or breathing, seek medical care promptly. For recurring reactions, a dermatologist can perform formal patch testing to identify the specific ingredient you are allergic to, which is far more reliable than guessing from labels.

Scanning a product with the Goby AI app can help you flag fragrance and known irritants quickly, but it does not replace patch testing or advice from a dermatologist, and you should always check the label on the package you bought, since formulas change.