Used as a preservative, fungicide, and to reduce bacteria count in solutions. It may also be used under the trade name formalin. It is not used too often in cosmetics because of its overpowering odor, but it can cause allergic reactions. Potentially carcinogenic and definitely toxic.
Formaldehyde (/fɔːrˈmældɪhaɪd/ (
listen) for-MAL-di-hide, US also /fər-/ (listen) fər-) (systematic name methanal) is a naturally occurring organic compound with the formula CH2O and structure H−CHO. The pure compound is a pungent, colourless gas that polymerises spontaneously into paraformaldehyde (refer to section Forms below), hence it is stored as an aqueous solution (formalin), which is also used to store animal specimens. It is the simplest of the aldehydes (R−CHO). The common name of this substance comes from its similarity and relation to formic acid.
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| Names | |||
|---|---|---|---|
| Preferred IUPAC name
Formaldehyde | |||
| Systematic IUPAC name
Methanal | |||
| Other names
Methyl aldehyde
Methylene glycol (diol forms in aqueous solution) Methylene oxide Formalin (aqueous solution) Formol Carbonyl hydride | |||
| Identifiers | |||
3D model (JSmol)
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| 3DMet | |||
| 1209228 | |||
| ChEBI | |||
| ChEMBL | |||
| ChemSpider | |||
| DrugBank | |||
| ECHA InfoCard | 100.000.002 | ||
| EC Number |
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| E number | E240 (preservatives) | ||
| 445 | |||
| KEGG | |||
| MeSH | Formaldehyde | ||
PubChem CID
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| RTECS number |
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| UNII | |||
| UN number | 2209 | ||
CompTox Dashboard (EPA)
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| Properties | |||
| CH2O | |||
| Molar mass | 30.026 g·mol−1 | ||
| Appearance | Colorless gas | ||
| Density | 0.8153 g/cm3 (−20 °C) (liquid) | ||
| Melting point | −92 °C (−134 °F; 181 K) | ||
| Boiling point | −19 °C (−2 °F; 254 K) | ||
| 400 g/L | |||
| log P | 0.350 | ||
| Vapor pressure | > 1 atm | ||
| Acidity (pKa) | 13.27 (hydrate) | ||
| −18.6·10−6 cm3/mol | |||
| 2.330 D | |||
| Structure | |||
| C2v | |||
| Trigonal planar | |||
| Thermochemistry | |||
Heat capacity (C)
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35.387 J·mol−1·K−1 | ||
Std molar
entropy (S⦵298) |
218.760 J·mol−1·K−1 | ||
Std enthalpy of
formation (ΔfH⦵298) |
−108.700 kJ·mol−1 | ||
Gibbs free energy (ΔfG⦵)
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−102.667 kJ·mol−1 | ||
Std enthalpy of
combustion (ΔcH⦵298) |
571 kJ·mol−1 | ||
| Pharmacology | |||
| QP53AX19 (WHO) | |||
| Hazards | |||
| GHS labelling: | |||
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| Danger | |||
| H301, H311, H314, H317, H331, H335, H341, H350, H370 | |||
| P201, P280, P303+P361+P353, P304+P340+P310, P305+P351+P338, P308+P310 | |||
| NFPA 704 (fire diamond) | |||
| Flash point | 64 °C (147 °F; 337 K) | ||
| 430 °C (806 °F; 703 K) | |||
| Explosive limits | 7–73% | ||
| Lethal dose or concentration (LD, LC): | |||
LD50 (median dose)
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100 mg/kg (oral, rat) | ||
LC50 (median concentration)
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333 ppm (mouse, 2 h) 815 ppm (rat, 30 min) | ||
LCLo (lowest published)
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333 ppm (cat, 2 h) | ||
| NIOSH (US health exposure limits): | |||
PEL (Permissible)
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TWA 0.75 ppm ST 2 ppm (as formaldehyde and formalin) | ||
REL (Recommended)
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Ca TWA 0.016 ppm C 0.1 ppm [15-minute] | ||
IDLH (Immediate danger)
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Ca [20 ppm] | ||
| Safety data sheet (SDS) | MSDS(Archived) | ||
| Related compounds | |||
Related aldehydes
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Acetaldehyde Butyraldehyde | ||
Related compounds
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Methanol Formic acid | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Formaldehyde is an important precursor to many other materials and chemical compounds. In 1996, the installed capacity for the production of formaldehyde was estimated at 8.7 million tons per year. It is mainly used in the production of industrial resins, e.g., for particle board and coatings.
