What it is
In the register’s words: “Acetic Acid is the organic acid.”
- EU register name (INCI)
- ACETIC ACID
- CAS number
- 64-19-7
- EC number
- 200-580-7
- Written on these labels as
- Acetic Acid; Acetic Acid (Apple Cider)
What the register lists it for
These are the uses the European Commission’s CosIng register lists for Acetic 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.
- Buffering
-
Keeps the product’s pH (how acidic it is) steady.
Register definition: “Stabilising the pH of an aqueous medium in a narrow range even if an acid or base is added. Altering and/or maintaining a cosmetic product's pH at the desired level.”
- Fragrance
-
Gives the product its smell or covers an unpleasant one. A label may name each scent ingredient or group them as Fragrance (Parfum).
Register definition: “Imparting an odour or taste. Creating a perceivable pleasant smell and/or masking a bad smell.”
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 2 labels First five names: 0 of 2 Shampoos without it
- Clarifying shampoos 1 label First five names: 0 of 1 Clarifying shampoos without it
- Rinse-out conditioners 2 labels First five names: 0 of 2 Rinse-out conditioners without it
- Deep conditioners 2 labels First five names: 0 of 2 Deep conditioners without it
Every label, product by product (7)
- SheaMoisture Jamaican Black Castor Oil Strengthen & Restore Shampoo Shampoo · listed as Acetic Acid (Apple Cider) 15th of 27 names
- OLAPLEX No.4 Bond Maintenance Strengthening Shampoo Shampoo 62nd of 78 names
- Aunt Jackie's Power Wash Intense Moisture Clarifying Shampoo Clarifying shampoo 30th of 30 names
- SheaMoisture Jamaican Black Castor Oil Strengthen & Restore Conditioner Rinse-out conditioner · listed as Acetic Acid (Apple Cider) 12th of 29 names
- OLAPLEX No.5 Bond Maintenance Strengthening Conditioner Rinse-out conditioner 56th of 66 names
- SheaMoisture Jamaican Black Castor Oil Strengthen & Restore Treatment Masque Deep conditioner · listed as Acetic Acid (Apple Cider) 27th of 35 names
- Kristin Ess Strand Strengthening Reconstructive Moisture Mask Deep conditioner 42nd of 50 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 buffering ingredients on these labels
- Citric Acid 93 labels
- Sodium Hydroxide 25 labels
- Aminomethyl Propanol 15 labels
- Lactic Acid 12 labels
- Sodium Acetate 7 labels
- Disodium Phosphate 6 labels
- Sodium Lactate 5 labels
- Sodium Phosphate 5 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.