murphyMethenamine
AKA: Hexamethylenetetramine, 100-97-0, Hexamine, Urotropine, Urotropin, 1, 3, 5, 7-Tetraazaadamantane, Uritone, HMTA, Hexamethylenamine
Synthetic
Preservative
Not Clean
OriginSynthesized from ammonia and formaldehyde through condensation reactions to form a heterocyclic compound.
Produced by heating formaldehyde and ammonia together under controlled conditions to create hexamethylenetetramine crystals.
1,3,5,7-Tetraazatricyclo[3.3.1.1(3,7)]decane
Solubility greater than or equal to 100 mg/mL at 68 °F (NTP, 1992)
Formula
C6H12N4
Mol. Weight
140.19
CAS #
100-97-0
Form
Liquid
State
Hexamethylenetetramine appears as odorless white crystalline powder or colorless lustrous crystals. Sublimes in a vacuum at about 505 °F with some decomposition. Solutions are strong bases (pH of 0.2
Skin Types
●all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Caution
Functions
Antimicrobial
Keeps your product from growing bacteria, mold, or yeast. Without these, that jar of cream becomes a petri dish in about a week.
Preservative
Keeps your product from growing bacteria, mold, or yeast. Without these, that jar of cream becomes a petri dish in about a week.
Fights Bacteria
The paper trail
🔬Peer-reviewed1 paper →
⚖️Regulatory1 listing →
🛡️Safety-assessed1 review →
Counts, not a verdict. A listing isn't a study. The trail, you decide.
EWG
4
CIR
Safe as used
Pregnancy
Caution
CIR Safety Findings
Not a Sensitizer
2 studies / 2 not sensitizing / plus 1 case report (CIR 108)
Mixed Eye Irritation Results
2 studies / 1 irritating / 1 not irritating / reactions mild (CIR 108)
Mixed Skin Irritation Results
2 studies / 1 irritating / 1 not irritating / reactions slight (CIR 108)
Concentration Guide
0%50%100%
Reg. limit 0.15%
EU regulatory limit: 0.15%. Source: EU Cosmetics Regulation (EC) 1223/2009, Annex V (Preservatives), Entry 30.
Regulatory Agencies
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR