What it is
In the register’s words: “Diazolidinyl Urea is the heterocyclic substituted urea.”
- EU register name (INCI)
- DIAZOLIDINYL UREA
- CAS number
- 78491-02-8
- EC number
- 278-928-2
What the register lists it for
These are the uses the European Commission’s CosIng register lists for Diazolidinyl Urea 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 1 label First five names: 0 of 1 Shampoos without it
- Rinse-out conditioners 1 label First five names: 0 of 1 Rinse-out conditioners without it
- Deep conditioners 1 label First five names: 0 of 1 Deep conditioners without it
- Stylers 1 label First five names: 0 of 1 Stylers without it
- Protein treatments 1 label First five names: 0 of 1 Protein treatments without it
Every label, product by product (5)
- Maui Moisture Curl Quench + Coconut Oil Shampoo Shampoo 22nd of 24 names
- Maui Moisture Curl Quench + Coconut Oil Conditioner Rinse-out conditioner 24th of 26 names
- Maui Moisture Heal & Hydrate + Shea Butter Hair Mask Deep conditioner 24th of 26 names
- Maui Moisture Curl Quench + Coconut Oil Curl Smoothie Styler 27th of 28 names
- Curl Junkie Repair Me! Reconstructive Hair Treatment Protein treatment 20th of 22 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
- Dehydroacetic Acid 23 labels
- Iodopropynyl Butylcarbamate 10 labels
- Methylchloroisothiazolinone 6 labels
- Methylisothiazolinone 6 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.