Formaldehyde

AKA: Formalin, Methanal, 50-00-0, Formol, Formic aldehyde, Methylene oxide, Oxomethane, Oxymethylene, Methyl aldehyde
Synthetic
Preservative
Not Clean
OriginSynthesized from the chemical family of simple aldehydes derived from methanol or natural gas feedstocks. Produced through catalytic oxidation of methanol using a silver or copper catalyst at high temperatures.
Formaldehyde is a highly reactive aldehyde gas formed by oxidation or incomplete combustion of hydrocarbons. In solution, it has a wide range of uses: in the manufacture of resins and textiles, as a disinfectant, and as a laboratory fixative or preservative. Formaldehyde solution (formalin) is considered a hazardous compound, and its vapor toxic. (From Reynolds, Martindale The Extra Pharmacopoeia, 30th ed, p717) -- Pubchem; The chemical compound formaldehyde (also known as methanal), is a gas with a pungent smell. It is the simplest aldehyde. Its chemical formula is H2CO. Formaldehyde was first synthesized by the Russian chemist Aleksandr Butlerov in 1859 but was conclusively identified by August Wilhelm van Hofmann in 1867. Although formaldehyde is a gas at room temperature, it is readily soluble in water, and it is most commonly sold as a 37% solution in water called by trade names such as formalin or formol. In water, formaldehyde polymerizes, and formalin actually contains very lit
Solubility Miscible (NIOSH, 2024)
Formula
CH2O
Mol. Weight
30.03
CAS #
50-00-0
Form
Liquid
State
Solids containing varying amounts of formaldehyde, probably as paraformaldehyde (polymers of formula HO(CH2O)xH where x averages about 30). A hazard to the environment. Immediate steps should be taken
Skin Types
●all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
No
Allergen Warning
⚠️ Formaldehyde
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.
Denaturant
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 →
⚖️Regulatory0 listings
🛡️Safety-assessed2 reviews →
Counts, not a verdict. A listing isn't a study. The trail, you decide.
EWG
10
CIR
Safe with qualifications (formalin concentration not above 0.2% (0.074% as formaldehyde); safe in nail hardeners; unsafe in hair-smoothing products)
Pregnancy
No
Restricted By
CIR Safety Findings
Mixed Eye Irritation Results
6 studies / 5 irritating / 1 mixed / reactions minimal to severe / plus 2 case reports (CIR 209 and 582)
Mixed Skin Irritation Results
6 studies / 3 irritating / 2 mixed / 1 not irritating / reactions minimal to severe / plus 3 case reports (CIR 209 and 582)
Mixed Sensitization Results
10 studies / 6 sensitizing / 3 mixed / 1 not sensitizing / plus 5 case reports (CIR 209 and 582)
Concentration Guide
0%50%100%
Reg. limit 5%
EU regulatory limit: 5%. 5 % (as formaldehyde). Protect cuticles with grease or oil Contains formaldehyde (3) Source: EU Cosmetics Regulation (EC) 1223/2009, Annex III (Restricted Substances), Entry 13.
Regulatory Agencies
🧂Conflict of interest.
Verified Jun 2026 · 🧪 = conflict
Data: PubChem · CosIng · EWG · CIR
murphy