acetic acid

Acid found in vinegar, some fruits, and human sweat. It can be sensitizing to skin...

acetone

Strong solvent that is used in Nail Polish removers.

calamine

Preparation of zinc carbonate, colored with ferric oxide (a form of rust). Zinc carbonate is a...

elecampane

Latin name Inula helenium; it is a plant that can be very sensitizing to the skin...

English ivy extract

Plant extract that can be a skin sensitizer due to its stimulant and astringent (skin-constricting) properties.

Equisetum arvense

esculin

Component of horse chestnut, it is considered harmful and is not recommended for skin...

essential oil

ethanol

ethyl alcohol

eucalyptus extract

Extract that may have beneficial properties on the skin...

eucalyptus oil

Fragrant plant oil whose active constituents are found in the leaves and the oil obtained from...

Eugenia aromatica

Eugenia caryophyllus

eugenol

Fragrance chemical that occurs naturally in some plant ingredients...

Euphrasia officinalis

eyebright

A plant; although the name sounds like it would be beneficial for the eye area, there are no...

comfrey extract

Several studies have shown that comfrey extract can have harmful properties when...

denatured alcohol

Denatured alcohol is a drying alcohol that weakens skin. If denatured alcohol is listed as the fifth ingredient or higher, it is of considerable risk for sensitising skin.

fennel oil

Volatile, fragrant oil that can cause skin sensitivity.

fennel seed extract

Can have antioxidant properties, but on skin it can be a skin sensitizer (Source:...

Ferula galbaniflua

feverfew extract

A plant that can be very soothing but also potentially sensitizing to the skin...

fir needle oil

Volatile, fragrant oil that can cause skin sensitivity.

Foeniculum vulgare extract

fragrance

One or a blend of volatile and/or fragrant plant oils (or synthetically derived oils) that impart...

frankincense extract

Fragrant component used in skincare products; it can be a skin sensitizer...

galbanum

Fragrant substance that, because of its resin and volatile oil content, can be extremely sensitizing…

Gardenia florida extract

Flower extract used in cosmetics to impart fragrance; also functions as an antioxidant (Source:...

geraniol

A volatile fragrance ingredient extracted from geranium, geraniol is capable of causing sensitivity when applied to skin.

geranium oil

Fragrant oil that can have beneficial properties but also can be a skin sensitizer...

Geranium pretense

Geranium plant.

ginger oil

isopropyl alcohol

ivy extract

Plant extract that can be sensitizing due to its astringent (skin-constricting) properties.

jasmine oil

Fragrant oil, often used as a source of perfume, that can be a skin sensitizer...

Jasminium grandiflorum

jonquil extract

Fragrant plant extract that poses a strong risk of skin sensitization.

juniper berry

Can have sothing properties for skin…

Juniperus communis

Kathon CG

kava-kava extract

Extract of the Piper methysticum plant that has soothing properties, but can...

kawa extract

kola nut

One of the major components of the kola nut is caffeine, which in high amounts can be a skin sensitizer...

lavandin oil

Essential oil of the hybrid lavender plant Lavandula hybrida and used in cosmetics as a fragrance...

Lavandula angustifolia

Lavandula officinalis

lavender extract and oil

In-vitro research indicates that components of lavender oil, specifically linalool and linalyl acetate, can have...

lemon

Potent skin sensitizer. Though it can have beneficial properties...

lemon balm

lemon juice

The juice from the citrus fruit lemon, often touted in the world of skin care as being a natural option for brightening skin.

lemon oil

Commonly used citrus oil that can be a skin sensitizer, especially on abraded skin.

lemongrass extract

Extract that can have beneficial properties...

lemongrass oil

Also known as Oil of Verbena; can be effective as a mosquito repellent...

Lentinus edodes extract

Extract from the shiitake mushroom that may have antioxidant properties...

gold

An ingredient that seems luxe and helpful but is actually a frequent contact sensitizer…

grapefruit oil

Citrus oil whose volatile components (chiefly substances known as furocoumarins) are sensitizing...

grapefruit peel extract

Typically listed as citrus grandis (grapefruit) peel extract on the ingredient list...

guarana

Herb that contains two and a half times more caffeine than coffee. It can have constricting...

Hamamelis virginiana

hamamelitannin

Tannin that is found in witch hazel. It can be a skin sensitizer but it also has antioxidant...

hayflower extract

Plant extract that, due to its constricting effect on skin, can be sensitizing There is no...

Hedera helix

hedione

Synthetic fragrant component in products, which also can be a skin sensitizer.

hexyl cinnamal

A fragrance ingredient used in many perfumes and often seen in fragranced skincare products...

horse elder

horseradish

Plant that can sensitize skin and should never be applied to abraded skin.

Hydnocarpus anthelmintica

Hydrastis canadenis

hydrogen peroxide

There is a great deal of current research showing that hydrogen peroxide is problematic as a...

Hypericum extract

Illicium vernum

Inula helenium

Iris florentina extract

Levisticum officinale root extract

lime oil and extract

Citrus fruit whose volatile compounds are sensitizing...

limonene

Chemical constituent of many natural fragrant ingredients, notably citrus oils such as lemon (d-limonene) and...

linalool

Fragrant component of lavender and coriander that can be a skin sensitizer, or...

Litsea cubeba

lovage root extract

In cosmetics, it is used as a fragrance....

lye

mandarin orange oil or extract

Primarily used as a fragrance; it can be a skin sensitizer. There is no research showing it has any...

marjoram

Herb with a fragrant component used in cosmetics; can be a skin sensitizer…

Melaleuca cajeputi oil

There is no research showing that this oil, which is derived from a plant in the same family as the...

Melia azadirachta oil

Melissa officinalis

Mentha arvensis

Mentha piperita

Mentha spicata

Mentha viridis

menthol

Derived from peppermint; menthol can have the same sensitizing effect as peppermint on skin…

menthone

Major constituent of peppermint.

menthoxypropanediol

Synthetic derivative of menthol. It is known to produce effects that are twice as strong as...

menthyl lactate

Used as a cooling agent and fragrance in cosmetics. It is a derivative of menthol and is supposed...

methanol

methylchloroisothiazolinone

In combination with methylisothiazolinone, it goes by the trade name Kathon CG (among others)....

methylisothiazolinone

Preservative that’s generally recommended for use only in rinse-off products such as cleansers or...

mint

Can be a skin sensitizer…

myrrh

Fragrant gum resin that can be a skin sensitizer. There is little research showing it has any benefit...

myrtle extract

Contains volatile oil and tannins...

Myrtus communis extract

Narcissus poeticus wax

Fragrant flower extract that can cause sensitizing reactions…

neroli

neroli oil

Fragrant plant oil that can be a skin sensitizer...

oak root extract

Extract that can be a skin sensitizer.

olibanum extract

orange blossom

Fragrant extract that can also be a skin sensitizer.

orchid

Fragrant flower that can be a skin sensitizer.

oregano

Has beneficial properties, but can also be a skin sensitizer.

Origanum majorana

Origanum vulgare flower extract

orris root

Used primarily as a fragrant component due to its violet-like scent (Source:...

sodium hydroxide

Also known as lye, it is a highly alkaline ingredient used in small amounts in cosmetics to...

sodium lauryl sulfate

Versatile ingredient composed of several non-volatile alcohols. Functions primarily as a surfactant...

sodium metabisulfite

Reducing agent that alters the structure of hair. It can also be used as a preservative in...

sodium silicate

Highly alkaline and potentially sensitizing mineral used in cosmetics...

sodium sulfite

Reducing agent that alters the structure of hair. It can also be used as a preservative in cosmetic...

sodium thioglycolate

A synthetic ingredinet that functions as a reducing agent in cosmetics, most typically hair-removal lotions...

Solanum lycopersicum extract

spearmint oil

Fragrant, volatile oil that can cause skin sensitivity.

star anise

sulfur

Disinfectant agent that can be a potent skin sensitizer...

Symphytum officinale extract

Szechuan peppercorn

From a plant native to Szechuan Province in China. It grows on trees, and so differs from black...

rose flower oil

Fragrant, volatile oil that can aggravate skin. There is no research showing...

sage extract

Plant used most often to enhance the flavor of foods. Like all plant extracts, sage...

sandalwood oil

Fragrant oil that can cause skin-sensitizing reactions...

Santalum album seed extract

Latin name for sandalwood extract, which is used in cosmetics as a fragrance. It can have...

sausurrea oil

Also called costus oil. Volatile oil and fragrant component used in cosmetics; it can be a skin...

SD alcohol

SD alcohol 40-2

Denatured alcohol used as a solvent. It can be drying and sensitizing to skin when one of the main...

sea salt

Can be effective as a topical scrub, but if left on skin it can increase skin sensitivity to UVB...

silver

Metallic element that in cosmetics can have disinfecting properties; however, prolonged contact can...

silver chloride

An inorganic salt that has no known function in cosmetics.

soap

True “soaps” are regulated by the Consumer Product Safety Commission and are not required to list...

sodium bisulfite

Used in acid-type permanent waves to alter the shape of hair. It is less damaging than alkaline...

sodium borate

sodium C14-16 olefin sulfonate

Can be derived from coconut. Used primarily as a detergent cleansing agent, but is potentially...

sodium carbonate

Absorbent salt used in cosmetics; it can also be a skin sensitizer.

sodium cocoate

Used as a cleansing agent primarily in soaps. It can be drying and sensitizing for skin.

Tanacetum parthenium

tangerine oil

Fragrant, volatile citrus oil that can be a skin sensitizer…

TEA-lauryl sulfate

While there is abundant research showing sodium lauryl sulfate is a sensitizing cleansing agent,...

thyme extract

Extract derived from the leaf or flower of the thyme plant. It can have potent antioxidant...

thyme oil

The most concentrated part of the thyme plant, and a source of antioxidants, some of which...

Thymus serpillum extract

Extract of wild thyme.

Thymus vulgaris

Thymus vulgaris oil

Thymus vulgaris oil is more commonly known as thyme oil.

tomato extract

Extract that has weak antioxidant properties...

tormentil extract

Plant that can be irritating due to its tannin content, which causes skin constriction.

trigonella foenum-graecum seed extract

Latin name for the fenugreek plant. The seeds are used most often, and their fiber content helps...

verbena extract

Fragrant extract that can be a skin sensitizer...

vetiver oil or extract

Fragrant component in skincare products that also has some beneficial properties...

vitamin B2

There is no research showing this has any benefit when applied topically to skin. However, there is...

volatile oil

Group of volatile fluids derived primarily from plants and used in cosmetics primarily as fragrant...

white nettle

Contains components that can have both soothing and sensitizing properties...

white oak bark extract

wild ginger

wintergreen oil

A type of mint often used to ease the discomfort of sore muscles...

witch hazel

Commonly used plant extract that can have antioxidant properties...

Xi xin

yarrow extract

Extract for which there is little research showing it to have any benefit for skin. What studies do...

ylang ylang

Fragrant, volatile oil that can also be a skin sensitizer…

yucca extract

Plant extract that can have soothing benefits...

Zanthoxylum piperitum

zinc carbonate

zinc sulfate

Chemical compound resulting from the interaction of zinc with sulfuric acid. There is little...

Zingiber officinale roscoe

Zingiber zerumbet

Zingiberaceae

neem oil

Neem oil contains a chemical known as nimbidin that gives it a sulfur-like odor.