DMDM imidazolidinyl urea
Also known as: Imidazolidinyl urea, DMDM imidazolidinyl urea, Formaldehyde releaser, Preservative, Imidazolidinyl Urea
Overview
Imidazolidinyl urea is a synthetic preservative widely used in cosmetics and personal care products. It functions by slowly releasing formaldehyde, which acts as an antimicrobial agent, preventing the growth of bacteria and fungi. It is not naturally derived but chemically synthesized. Primarily used in products like shampoos, lotions, and creams, it extends shelf life by inhibiting microbial contamination. While effective, the released formaldehyde can cause allergic reactions in some individuals. The safety and allergenic potential have been studied extensively, including reviews by the Cosmetic Ingredient Review (CIR) panel. Despite some data gaps, it is generally considered safe at low concentrations, but its allergenic potential remains a concern.
Benefits
Imidazolidinyl urea is not used for direct health benefits but as a preservative in cosmetics to maintain product integrity and prevent microbial contamination. Its primary role is to extend the shelf life and safety of cosmetic products. There are no direct health benefits to consumers; rather, its role is to maintain product integrity. It ensures that products remain free from harmful bacteria and fungi, which could otherwise cause skin infections or product degradation. However, it's important to note that while it prevents microbial growth, it can also cause allergic reactions in some individuals.
How it works
Imidazolidinyl urea works by slowly releasing formaldehyde in aqueous solutions. This formaldehyde acts as a biocide, denaturing microbial proteins and DNA, thereby inhibiting microbial growth. Upon skin contact, the released formaldehyde can bind to skin proteins, potentially triggering immune responses in sensitized individuals. The formaldehyde targets microbial enzymes and proteins, leading to microbial death. Systemic absorption is minimal, but localized skin reactions can occur. This mechanism ensures that cosmetic products remain free from microbial contamination, extending their shelf life and maintaining their safety.
Side effects
Imidazolidinyl urea is generally considered safe at low concentrations (up to 0.6% in leave-on products) but is a known allergen. Common side effects include allergic contact dermatitis in sensitized individuals and skin irritation. Uncommon side effects (1-5%) may include mild skin irritation or redness. Rare side effects (<1%) can include severe allergic reactions, including eczema flare-ups. Individuals with known formaldehyde allergy or sensitivity to formaldehyde releasers should avoid products containing imidazolidinyl urea. Caution is advised for individuals with sensitive skin or a history of contact dermatitis. While systemic drug interactions are not significant due to minimal absorption, some evidence suggests potential fetotoxicity in animal studies.
Dosage
Imidazolidinyl urea is not used as a supplement; its usage is regulated in cosmetics. The maximum allowed concentration in leave-on products is typically 0.6%. There is no dosing for ingestion or supplementation. The concentration is carefully controlled to balance its effectiveness as a preservative with its potential to cause allergic reactions. Regulatory bodies like the CIR set these limits to ensure consumer safety. It is crucial to adhere to these concentration limits to minimize the risk of adverse effects while maintaining product integrity.
FAQs
Is imidazolidinyl urea safe in cosmetics?
Generally yes, at regulated concentrations (up to 0.6%), but it can cause allergic reactions in some people, especially those with formaldehyde sensitivity.
Can it cause cancer?
Formaldehyde is a known carcinogen, but the amount released by imidazolidinyl urea in cosmetics is very low. However, some mutagenicity concerns have been raised in studies.
Should people with sensitive skin avoid it?
Yes, especially those with a formaldehyde allergy or a history of dermatitis, as it can trigger allergic contact dermatitis.
Is it the same as DMDM hydantoin?
No, they are different formaldehyde releasers but related in function, both used as preservatives in cosmetics.
Research Sources
- https://pubmed.ncbi.nlm.nih.gov/35229319/ – This systematic review highlights that imidazolidinyl urea is a known formaldehyde releaser and a common cause of allergic contact dermatitis. Patch testing with 2% diazolidinyl urea (a related compound) is recommended to detect sensitization. Avoidance is advised for sensitized individuals.
- https://onlinelibrary.wiley.com/doi/full/10.1111/cod.14258 – This review identifies imidazolidinyl urea as a significant allergen in vulvar allergic contact dermatitis, underscoring its role as a preservative that can cause irritant and allergic reactions in sensitive skin areas. It provides a comprehensive list of allergens including formaldehyde releasers, supporting the need for careful patch testing and avoidance strategies in affected populations.
- https://www.cir-safety.org/sites/default/files/Imidazolidinyl%20Urea.pdf – The CIR panel reviewed imidazolidinyl urea safety data, noting decreased usage frequency but reaffirming safety at current concentrations (up to 0.6%). The panel acknowledged mutagenicity and fetotoxicity concerns from some studies but concluded that available data do not warrant reopening the safety assessment.
- https://pubmed.ncbi.nlm.nih.gov/20136875/ – This study investigates the allergenic potential of formaldehyde-releasing preservatives, including imidazolidinyl urea, in cosmetic products. It highlights the importance of patch testing to identify sensitized individuals and emphasizes the need for careful product selection to avoid allergic reactions.
- https://womensvoices.org/wp-content/uploads/2018/04/CIR_final_report.pdf – This report summarizes the Cosmetic Ingredient Review (CIR) Expert Panel's assessment of imidazolidinyl urea. The panel reviewed available data and concluded that imidazolidinyl urea is safe for use in cosmetics at current concentrations, while acknowledging potential concerns regarding mutagenicity and fetotoxicity.
