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Skincare Ingredient

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Diazolidinyl Urea

In Skincare: Is Diazolidinyl Urea Safe? Comedogenic Rating & Side Effects

Safety (overall safety)
3/5 — Moderate risk
Irritancy (skin irritation)
4/5 — High risk

Safety Information

The Cosmetic Ingredient Review (CIR) Expert Panel has noted that repeated exposure may lead to sensitization, and it is recommended to avoid use in products intended for prolonged skin contact.

Overview

Ingredient Profile

Diazolidinyl urea is a water-soluble preservative commonly used in skincare formulations to prevent microbial growth. It functions as a formaldehyde-releasing preservative, though the levels of formaldehyde released are typically low and within safe exposure limits. When used at concentrations up to 0.5%, often in combination with other preservatives, it helps maintain product integrity and safety. Formaldehyde released by this ingredient is often quickly neutralized by other components in the formula, minimizing potential skin irritation.
Classifications
Preservative

Data & Research

Scientific Facts

Diazolidinyl urea functions as a preservative by slowly releasing formaldehyde into the formulation. It is effective against bacteria, yeast, and molds, thereby minimizing product contamination.

Common Uses

Formulation in Diazolidinyl Urea

Diazolidinyl urea prevents or slows the growth of bacteria, yeast, and mold within cosmetic products. This helps to maintain product stability and prevent spoilage, protecting the formulation from contamination during consumer use.

Role of Diazolidinyl Urea

Active Cosmetic Mechanisms

PRESERVATIVE

Product Protector

Prevents microbial contamination and extends shelf life

SCIENTIFIC ANALYSIS

// Evidence: Preservatives inhibit microbial growth through various mechanisms: disrupting cell membranes (phenoxyethanol, parabens), releasing formaldehyde (DMDM hydantoin), chelating essential nutrients, or creating unfavorable pH. Broad-spectrum preservatives target bacteria, yeast, and mold. Efficacy depends on concentration, pH, formulation type, and microbial challenge. Must pass preservative efficacy testing (PET/challenge testing) meeting USP, EP, or JP standards.

Products

containing Diazolidinyl Urea

665 formulations
Denní Krém S Amarantovým Olejem A Hedvábím
Denní Krém S Amarantovým Olejem A Hedvábím
Ryor · moisturizer
HydraFresh Toner
HydraFresh Toner
L'Oreal · toning-essences
Bienfait Multi-Vital Eye Sunscreen Broad Spectrum SPF 30
Bienfait Multi-Vital Eye Sunscreen Broad Spectrum SPF 30
Lancôme · eye-lip-care
"Electric Feels" Whipped Shave Butter
"Electric Feels" Whipped Shave Butter
Soap Cute California · body-skincare
Výživný Krém S Přírodními Oleji
Výživný Krém S Přírodními Oleji
Ryor · moisturizer
Výživný Krém Exclusive
Výživný Krém Exclusive
Ryor · moisturizer
Výživný Krém S Mandlovým Olejem
Výživný Krém S Mandlovým Olejem
Ryor · moisturizer
Cocoa Butter Hand & Body Lotion
Cocoa Butter Hand & Body Lotion
Queen Helene · body-skincare
Complex 15 Daily Face Cream
Complex 15 Daily Face Cream
Bayer · moisturizer
"Cocoa Kisses" Whipped Sugar Body Scrub
"Cocoa Kisses" Whipped Sugar Body Scrub
Soap Cute California · body-skincare
See all products with Diazolidinyl Urea

References

Scientific sources

[1]

Steinberg, David C., Preservatives for Cosmetics, Third Edition, Allured Books, 2012, pages 67-68

[2]

Contact Dermatitis, August 2011, pages 81-91; and January 2006, pages 50-58

[3]

International Journal of Toxicology, March-April 1990, issue 2, pages 229-245

Semantic Analysis

Similar Ingredients

Ingredients with similar chemical profiles and skincare properties.

Frequently Asked Questions

Diazolidinyl Urea — common questions

What is Diazolidinyl Urea in skincare?

Diazolidinyl urea is a white powder used as a preservative in cosmetic and personal care products. It’s commonly found in items such as makeup, aftershave, nail care, bath products, hair care, and skin care formulations.

What does Diazolidinyl Urea do? / Functions of Diazolidinyl Urea?

Common functions: PRESERVATIVE.

What is the comedogenic rating of Diazolidinyl Urea? / Is Diazolidinyl Urea comedogenic?

The comedogenic rating of Diazolidinyl Urea has not been established in our database.

Does it clog pores?
No Rating Available

Whether Diazolidinyl Urea clogs pores depends on the formulation and concentration.

Is Diazolidinyl Urea safe for skin?
3 3/5 — Moderate risk

Diazolidinyl Urea has a safety rating of 3 out of 5. A rating of 3 indicates moderate safety considerations. Note: The Cosmetic Ingredient Review (CIR) Expert Panel has noted that repeated exposure may lead to sensitization, and it is recommended to avoid use in products intended for prolonged skin contact.

Is Diazolidinyl Urea good for sensitive skin?
4 4/5 — High risk

Diazolidinyl Urea has an irritancy rating of 4 out of 5. A rating of 4 means it has high irritation potential.

What are the side effects of Diazolidinyl Urea in skincare?

Known considerations: The Cosmetic Ingredient Review (CIR) Expert Panel has noted that repeated exposure may lead to sensitization, and it is recommended to avoid use in products intended for prolonged skin contact. Additional risks: skin irritation (irritancy rating 4/5).

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