Skin Allergy Knowledge Base

what is this?

We wanted to know which ingredients we should and shouldn’t put in our personal care products, so we did the research. Then we thought, why not share the love?

This Skin Allergy Knowledge Base is a comprehensive (yet likely still incomplete) list of the personal care ingredients that most commonly cause an allergic reaction or irritation to the skin. This includes ingredients often used in lotions, soaps, deodorants, body washes, shampoos, face creams, hair styling products, wipes, and more.

In presenting this information, two things are of utmost importance to us:

  1. No Bias: Full disclosure – we make personal care products. And of course we believe our products are great. But, we think it’s important to note that we have conformed our products to these findings, not the other way around.
  2. Plain English: A lot of ingredient information online is written in complex terms that are hard to grasp without a PhD in Chemistry. We want to share knowledge, not data. So we’ve translated the scientific speak into English and presented just what’s most important to you, the consumer.

Allergens vs. Irritants

When determining whether or not a personal care product’s ingredients are suitable for you or your child, it’s important to distinguish between allergens and irritants.

Allergens are ingredients that trigger an allergic reaction because the individual user happens to have an allergy to that ingredient. Allergic reactions tend to occur quickly after exposure to the allergen. Allergens affect a smaller portion of the population, but can cause more intense symptoms that may require immediate medical care depending on the severity of the reaction.

Irritants are ingredients that cause skin irritation because they are either harsh in nature or clash with the individual user’s body chemistry. Skin irritation caused by an irritant can occur immediately, but usually develops days or weeks after repeated exposure. Irritants affect a larger portion of the population, but typically cause less intense symptoms that can be self-treated.


What makes it tough to distinguish between allergens and irritants is the fact that they have almost identical symptoms. Most commonly these include:

  • Rash
  • Redness
  • Itchiness
  • Burning
  • Stinging
  • Swelling
  • Bumpy skin
  • Dry, cracked, or flaky skin

Allergens differ in that they can also sometimes cause hives, severe inflammation, nasal congestion, itchy eyes, dizziness, or difficulty breathing.


Our customers are kids – with particularly sensitive skin – so we’ve been rather strict in our classification of ingredients. Therefore, some ingredients might be flagged as irritants but for grown-ups irritation is actually quite rare.

Here are the classification categories we’ve used:

Potentially Irritating – These ingredients are known to cause skin irritation or damage for some people. This is different than an allergic reaction (but with similar symptoms), and affects a wider portion of the population. Sometimes irritation does not appear upon first use but develops from repeated use over time. Use with caution.

Potentially Allergenic – These ingredients are generally safe for people who aren’t allergic to them, but tend to be among the more common skin allergens. Skin reactions appear quite quickly after exposure and can range in severity. Avoid if allergic. If you’re unsure, test on a small patch of skin first.

Potentially Photosensitive – These ingredients can cause skin irritation with prolonged exposure to direct sunlight if used undiluted or at high concentrations. They are, however, generally safe for everyone when used 1) in rinse-off applications (e.g., body wash), 2) in leave-on applications on non-exposed skin (e.g., underarm deodorant), or 3) in leave-on applications on exposed skin at very low, diluted quantities (typically 0.5-2% of the total formula composition).

Ingredients are listed in alphabetical order.

Ingredient NameRisk Category
Abietic AcidPotentially Irritating
Almond ExtractPotentially Allergenic
Almond OilPotentially Allergenic
AluminumPotentially Irritating
Anisyl AlcoholPotentially Irritating
BenzaldehydePotentially Irritating
Benzalkonium ChloridePotentially Irritating
Benzoic AcidPotentially Irritating
Benzoyl PeroxidePotentially Allergenic
Bergamot OilPotentially Photosensitive
Bitter Orange OilPotentially Photosensitive
Camphor OilPotentially Irritating
Cassia Bark OilPotentially Allergenic
Cinnamon Bark OilPotentially Allergenic
Clove OilPotentially Irritating
Coconut OilPotentially Irritating
Potentially Allergenic
Cumin OilPotentially Photosensitive
Diazolidinyl UreaPotentially Irritating
Ethyl AlcoholPotentially Irritating
Fragrance (Parfum)Potentially Irritating
Potentially Allergenic
Grapefruit Peel OilPotentially Photosensitive
HexachlorophenePotentially Irritating
Horse Chestnut ExtractPotentially Allergenic
Imidazolidinyl UreaPotentially Irritating
Iodopropynyl ButylcarbamatePotentially Irritating
Potentially Allergenic
Isopropyl AlcoholPotentially Irritating
Jasmine AbsolutePotentially Allergenic
Lavender OilPotentially Allergenic
Lemon OilPotentially Photosensitive
Lime OilPotentially Photosensitive
Macadamia OilPotentially Allergenic
Massoia Bark OilPotentially Allergenic
MethylisothiazolinonePotentially Irritating
Potentially Allergenic
Mineral OilPotentially Irritating
Narcissus AbsolutePotentially Allergenic
Oregano OilPotentially Irritating
Peanut OilPotentially Allergenic
Peru Balsam OilPotentially Allergenic
PhenoxyethanolPotentially Irritating
Propylene GlycolPotentially Irritating
Propyl GallatePotentially Allergenic
Quaternium 15Potentially Irritating
Sage (Common) OilPotentially Irritating
Salicylic AcidPotentially Irritating
Potentially Allergenic
Sesame OilPotentially Allergenic
SiliconePotentially Irritating
Sodium Bicarbonate (Baking Soda)Potentially Irritating
Sodium Lauryl Sulfate (SLS)Potentially Irritating
Soy ExtractPotentially Allergenic
Tea Tree OilPotentially Irritating
Tolu Balsam OilPotentially Allergenic
TriclosanPotentially Irritating
Wintergreen OilPotentially Irritating