What it is
In the register’s words: “Dehydroacetic Acid is the cyclic ketone.”
- EU register name (INCI)
- DEHYDROACETIC ACID
- CAS number
- 520-45-6 / 771-03-9 / 16807-48-0
- EC number
- 208-293-9 / 212-227-4 / -
What the register lists it for
These are the uses the European Commission’s CosIng register lists for Dehydroacetic Acid in any cosmetic, hair roles first. They say why a maker might add it, not what it does in one formula, and they aren’t a safety rating.
- Preservative
-
Stops bacteria, mold and yeast growing in the bottle. EU law allows only the preservatives on its own list for this role.
Register definition: “Exclusively or mainly intended to inhibit the development of micro-organisms in the cosmetic product. All authorised preservatives are substances in the positive list of Annex V to the Cosmetics Regulation 1223/2009.”
Where it sits on each label
US labels list ingredients from most to least, except that those at 1% or less may follow in any order. A name near the top is a large part of the formula. A label doesn’t mark where the 1% point falls, so further down, the order says little about how much is in it.
- Shampoos 5 labels First five names: 0 of 5 Shampoos without it
- Rinse-out conditioners 3 labels First five names: 0 of 3 Rinse-out conditioners without it
- Deep conditioners 4 labels First five names: 0 of 4 Deep conditioners without it
- Leave-in conditioners 4 labels First five names: 0 of 4 Leave-in conditioners without it
- Stylers 5 labels First five names: 0 of 5 Stylers without it
- Protein treatments 1 label First five names: 0 of 1 Protein treatments without it
- Heat protectants 1 label First five names: 0 of 1 Heat protectants without it
Every label, product by product (23)
- Bouclème Curl Cleanser Shampoo 14th of 35 names
- Bouclème Fragrance Free Curl Cleanser Shampoo 13th of 18 names
- The Doux SUCKA FREE Moisturizing Shampoo Shampoo 19th of 23 names
- Giovanni Curl Habit Curl Defining Shampoo Shampoo 26th of 31 names
- Jessicurl Hair Cleansing Cream Shampoo 15th of 15 names
- Bouclème Fragrance Free Curl Conditioner Rinse-out conditioner 13th of 17 names
- Bouclème Curl Conditioner Rinse-out conditioner 30th of 38 names
- Jessicurl Too Shea! Extra Moisturizing Conditioner Rinse-out conditioner 30th of 31 names
- Bouclème Intensive Moisture Treatment Deep conditioner 39th of 50 names
- Giovanni Curl Habit Curl Defining Deep Conditioning Hair Mask Deep conditioner 23rd of 24 names
- Jessicurl Deep Conditioning Treatment Deep conditioner 29th of 30 names
- Briogeo Don’t Despair, Repair! Deep Conditioning Mask Deep conditioner 39th of 40 names
- Aunt Jackie's Quench! Moisture Intensive Leave-In Conditioner Leave-in conditioner 14th of 31 names
- Bouclème Curl Cream Leave-in conditioner 22nd of 38 names
- Giovanni Direct Leave-In Weightless Moisture Conditioner Leave-in conditioner 19th of 20 names
- Bouclème Fragrance Free Curl Cream Leave-in conditioner 17th of 17 names
- Bouclème Curl Defining Gel Styler 26th of 31 names
- Bouclème Super Hold Styler Styler 41st of 48 names
- Bouclème Fragrance Free Curl Defining Gel Styler 11th of 12 names
- Mielle Honey & Ginger Styling Gel Styler 16th of 17 names
- Giovanni Curl Habit Curl Shaping Hair Gel Styler 20th of 21 names
- Briogeo Don't Despair, Repair! MegaStrength+ Rice Water Protein + Moisture Strengthening Treatment Protein treatment 26th of 35 names
- Briogeo Farewell Frizz Blow Dry Perfection & Heat Protectant Crème Heat protectant 29th of 30 names
Each line runs from the first name on a label to the last; a dot is where this ingredient sits. Makers change formulas now and then; if the list on your bottle differs, go by your bottle.
Your next step
Other preservative ingredients on these labels
- Benzyl Alcohol 47 labels
- Iodopropynyl Butylcarbamate 10 labels
- Methylchloroisothiazolinone 6 labels
- Methylisothiazolinone 6 labels
- Diazolidinyl Urea 5 labels
- DMDM Hydantoin 3 labels
- Propylparaben 2 labels
Updated · The name, numbers and uses come from the European Commission’s CosIng entry (CC BY 4.0); we write the uses in US spelling and put the hair ones first. The labels are each maker’s own. The order rule is the FDA’s Cosmetics Labeling Guide. All our sources are on the Sources page.