Science
Mechanism of Action
TMHDI acts by readily reacting with various biological molecules on the skin, including water, proteins, and amines, often leading to exothermic reactions. This chemical reactivity directly causes severe skin irritation, chemical burns, and can induce allergic skin reactions and respiratory sensitization. It does not possess any known beneficial mechanisms for skin health.
Research
Clinical Evidence
Low confidenceN/A
Transparency
Dusting Analysis
Trimethylhexamethylene diisocyanate is not an ingredient intended for direct cosmetic application due to its extreme reactivity and hazardous profile. Its presence, even as a residual monomer in polymers used in cosmetics, is a significant safety concern. Regulatory guidance on related diisocyanates suggests strict control, with proposals for concentrations above 0.1% to be subject to a Significant New Use Rule in certain consumer products.
The Formula
Formulation
Stability
Trimethylhexamethylene diisocyanate exhibits high reactivity and is inherently unstable in the presence of water and moisture, reacting to produce toxic and flammable gases such as amine and carbon dioxide. Both acidic and basic conditions can initiate polymerization. Consequently, it lacks a stable optimal pH range for incorporation into aqueous formulations.
Conflicts
- water
- moisture
- amines
- aldehydes
- alcohols
- alkali metals
- ketones
- mercaptans
- strong oxidizers
- hydrides
- phenols
- peroxides
- acids
- bases
Safety
Safety Profile
The Cosmetic Ingredient Review (CIR) Expert Panel has not specifically assessed TRIMETHYLHEXAMETHYLENE DIISOCYANATE as a direct cosmetic ingredient, therefore no 'safe as used' status has been granted for the unreacted monomer. While some hexamethylene diisocyanate (HDI) polymers have been deemed safe for cosmetic use by CIR, this safety is strictly contingent on negligible residual monomer content. The unreacted monomer is widely recognized as an irritant and sensitizer. The EPA has identified diisocyanates, generally, for their potential to cause skin and lung sensitization, with a proposed Significant New Use Rule for related compounds at concentrations exceeding 0.1% in various consumer goods.
Your Skin
Skin Compatibility
Our Assessment
Verdict
Trimethylhexamethylene diisocyanate is a highly reactive industrial chemical known to cause irritation, burns, and sensitization, rendering it entirely unsuitable and unsafe for direct application in skincare formulations.
Related
Similar Ingredients
Finding similar ingredients…
References
Sources