This is a term I wish I knew years ago when I started playing around with oils. I seldom get pimples or blackheads, but using certain oils, especially coconut, would leave me with blemishes. If we look at the term “comedones” it means “acne-lesion”, which is a hard blockage caused by excess sebum building up in the skin. Comedogenic refers to the tendency of an ingredient to cause or aggravate comedones, which in simpler terms is likelihood that ingredient will clog your pores and cause blemishes (acne, blackheads and whiteheads).
The comedogenic scale goes from 0 (essentially non-comedogenic, will not likely cause or aggravate acne) to 5 (comedogenic, likely to cause or aggravate acne), and was originally created by continually rubbing oil on the fleshy parts of rabbit’s ear for two weeks. As consumers now frown upon animal testing, there have been many studies done on humans. Testing usually runs for about 4-6 weeks, and at the end of the testing a surface biopsy is conducted.
The human trials had mixed results; with some independent studies claiming one ingredient was non-comedogenic and others claiming it was comedogenic. This and that fact that the rabbit epidermis is not the same as the human epidermis raises questions about the validity of the scale. There does not seem to be a definite rating system and the ratings for ingredients seems to vary from source to source. For this reason I recommend only using the scale for reference, generally ingredients with high ratings, that have continually produced high ratings, should be avoided in large, concentrated quantities, especially those who are acne prone, and ingredients with low ratings can be used a little more freely. Wash off products, like soap, are less likely to affect your pores than products that are left on the skin, like body butters and serums.
I've compiled a list of the most comedogenic ratings for ingredients below. Products with ratings from 0-2 are okay for concentrated use in leave-on products and products with a 3 and up, avoid or use at very small concentrations.
Scale
0 – Won’t clog pores
1 – Low
2 – Moderately Low
3 – Moderate
4 – Fairly High
5 - High
Oils & Butters
Almond Oil - 2
Apricot Kernel Oil - 2
Argan Oil - 0
Avocado Oil - 2
Baobab Oil - 2
Borage Oil - 2
Calendula Oil - 1
Camphor - 2
Capuacu - 0
Castor Oil - 1
Cocoa Butter - 4
Coconut Butter - 4
Coconut Oil - 4
Corn Oil - 3
Cotton Seed Oil - 3
Emu Oil - 1
Evening Primrose Oil - 2
Flax Seed Oil - 4
Grape Seed Oil - 2
Hazelnut Oil - 2
Hemp Seed Oil - 0
Jojoba Oil - 2
Jojoba Oil Sulfated - 3
Linseed Oil - 4
Mango Butter - 0
Mineral Oil - 0
Mink Oil - 3
Neem Oil - 1
Olive Oil - 2
Palm Oil - 4
Peach Kernel Oil - 2
Peanut Oil - 2
Petrolatum - 0
Pomegranate Oil - 1
Pumpkin Seed Oil - 2
Rosehip Oil - 1
Safflower Oil (Carthamus tinctorius) - 0
Sandalwood Seed Oil - 2
Sea Buckthorn Oil - 1
Sesame Oil - 2
Shea Butter - 0
Soybean Oil - 3
Sunflower Oil - 0
Tamanu Oil - 2
Wheat Germ Oil - 5
Shark Liver Oil - 3
Waxes
Beeswax - 2
Candelilla Wax - 1
Carnuba Wax - 1
Ceresin Wax - 0
Emulsifying Wax NF - 2
Lanolin Wax - 1
Botanicals
Algae Extract - 5
Aloe Vera Gel - 0
Calendula - 1
Carrageenans - 5
Chamomile - 2
Chamomile Extract - 0
Cold Pressed Aloe - 0
Red Algae - 5
Vitamins & Herbs
Ascorbic Acid - 0
Black Walnut Extract - 0
Tocopherol (Vitamin E) - 2
Vitamin A Palmitate - 2
Panthenol - 0
Antioxidants
Beta Carotene - 1
BHA - 2
Minerals
Algin - 4
Colloidal Sulfur - 3
Flowers of Sulfur - 0
Potassium Chloride - 5
Precipitated Sulfur - 0
Sodium Chloride (Salt) - 5
Talc - 1
Zinc Stearate - 0
Thickeners, Emulsifiers, Detergents
Carbomer 940 - 1
Hydroxypropyl Cellulose - 1
Kaolin - 0
Magnesium Aluminum Silicate - 0
Sodium Laureth Sulfate - 3
Sodium Lauryl Sulfate - 5
Sorbitan Oleate - 3
Alcohol, Esters, Ethers, & Sugars
Polysorbate 20 - 0
Polysorbate 80 - 0
Sterol Esters - 0
Behenyl Triglyceride - 0
Butylene Glycol - 1
Cetearyl Alcohol - 2
Diethylene Glycol Monomethyl Ether-0
Glycerin - 0
Glyceryl Stearate NSE - 1
Glyceryl Stearate SE - 3
Glyceryl Tricapylo/Caprate - 1
Glyceryl-3-Diisostearate - 4
Hexadecyl Alcohol - 5
Isocetyl Stearate - 5
Isopropyl Alcohol - 0
Laureth 23 - 3
Laureth 4 - 5
Octyl Stearate - 5
Oleth-10 - 2
Oleth-3 - 5
Oleyl Alcohol - 4
Polyethylene Glycol (PEG 400) - 1
Polyethylene Glycol 300 - 1
Polyglyceryl-3-Diisostearate - 4
Propylene Glycol - 0
Propylene Glycol Monostearate - 4
SD Alcohol 40 - 0
Sorbitan Laurate - 1
Sorbitol - 0
Steareth 10 - 4
Steareth 100 - 0
Steareth 2 - 2
Steareth 20 - 2
Wheat Germ Glyceride - 3