If you’ve ever stared at a product’s cosmetic ingredient labels and wondered what everything means, you’re not alone. The 1% rule in cosmetics can help you figure out which ingredients actually matter and which are mostly fillers. This guide will show you how to read cosmetic ingredient labels like a pro and choose skincare products with confidence.

How Are Ingredients Listed on a Cosmetic Label?

Cosmetic ingredient lists are arranged following the International Nomenclature of Cosmetic Ingredients (INCI) standards. The order of ingredients follows these principles:

• Ingredients are listed in descending order of their concentration.
• Ingredients present at 1% or more are listed first, in order of predominance.
• Ingredients present at less than 1% can be listed in any order after the 1% threshold ingredients.
• Ingredients such as preservatives, colorants, and fragrances, which are present in very small amounts, are typically listed toward the end of the ingredient list.

Understanding the 1% Mark on a Cosmetic Label

The 1% mark on an ingredient list isn’t explicitly labeled, but you can estimate it using some handy clues. Here’s how:

Clue 1: Find preservatives

Preservatives (like Phenoxyethanol, Potassium Sorbate) are usually below 1%.

Examples of Preservatives

• Phenoxyethanol (known to be used below 1% due to regulations)
• Caprylyl Glycol
• Glyceryl Caprylate
• Sodium Benzoate
• Potassium Sorbate
• Ethylhexylglycerin
• Benzyl Alcohol
• Chlorphenesin
• Lactobacillus Ferment (commonly used more than 1%) – skip this!

Preservatives Less Commonly Used Today

• Parabens (e.g., methylparaben, propylparaben)
• BHT
• Imidazolidinyl Urea

Clue 2: Find Fragrance and Colorants

Any ingredients listed after Fragrance (Parfum) or colorants (listed as Yellow 5, Blue 1, Red 40…) are likely below 1% in skincare on a Cosmetic Label. Body care and hair care products typically contain a lot of fragrance, so it’s likely that the concentration exceeds 1%.

Clue 3: Find Thickening Agents

Thickeners are highly effective at low concentrations and are almost always below 1%.

Examples of Preservatives

• Carbomers
• Acrylates Copolymer
• Hydroxyethylcellulose
• Polyacrylate Crosspolymer-6
• Acrylates/C10-30 Alkyl Acrylate Crosspolymer
• Sodium Polyacrylate
• Ammonium Acryloyldimethyltaurate/VP Copolymer
• Xanthan Gum
• Cellulose Gum

Clue 4: Look for ingredients listed in ppm

Cosmetic companies often avoid using percentages for small amounts because listing them in ppm can make the quantity seem larger. Since 10,000 ppm equals 1%, values like 1,000 ppm or 5,000 ppm are below 1%. Therefore, checking for ppm values can be helpful.

Here’s an example ingredient list I made:

<Example Ingredient List 1>

Water, Dipropylene Glycol, Polyglyceryl-10 Laurate, 1,2-Hexanediol, Caffeine, Simmondsia Chinensis (Jojoba) Seed Oil, Hydroxyethylcellulose, Squalane, Maltodextrin, Caprylic/Capric Triglyceride, Caprylyl Glycol, Chamomilla Recutita (Matricaria) Flower Extract, Lactobacillus Ferment, Aloe Barbadensis Flower Extract, Sodium Hyaluronate, Beta-Glucan, Pearl Powder, Phenoxyethanol, Glycerin, Curcuma Longa (Turmeric) Root Extract, Butylene Glycol, Cellulose Gum, Hydrogenated Lecithin, Sodium Phytate, Citrus Limon (Lemon) Peel Oil, Limonene, Citral, Linalool

In this case, I’m guessing the 1% mark is hydroxyethylcellulose. So, anything listed after hydroxyethylcellulose is likely below 1%, meaning it’s probably added in very small amounts.

<Example Ingredient List 2>

Water, Glycerin, Butylene Glycol, Pentylene Glycol, Hydrogenated Vegetable Oil, Cetearyl Alcohol, Squalane, Hydrogenated Lecithin, Glyceryl Caprylate, Citric Acid, Sodium Hyaluronate (1000ppm), Sodium Chloride, Fragrance(Parfum), Macadamia Integrifolia Seed Oil, Palmitic Acid, Dimethicone, Pentaerythrityl Tetra-di-t-butyl Hydroxyhydrocinnamate, Polyacrylate Crosspolymer-6, Niacinamide, Hydrogenated Olive Oil Unsaponifiables, Sodium Phosphate, Dipotassium Glycyrrhizate

Similarly, the expected 1% mark is Glyceryl Caprylate.

The Importance of Identifying the 1% Mark on a Cosmetic Label

Cosmetic formulators know the properties of each ingredient, so it’s easier for me to pinpoint the 1% mark. Of course, there are always exceptions, so this is just an educated guess from a cosmetic chemist’s perspective ! But with the clues I’ve shared, I hope you can get a pretty good idea of where the 1% mark might be too.

But why is finding the 1% mark important? Well, I don’t think ingredients added in tiny amounts really have much of an effect on the skin—unless it’s an OTC product. (OTC stands for “Over-The-Counter,” which means products regulated as drugs.) This can be a helpful trick when choosing cosmetics!