Formaldehyde
POM · P-FORMALDEHYDE · POLYFORMALDEHYDE · POLYACETAL · PARAFORM · ACETAL RESIN · Paraformalclehyde · FORMALDEHYDE RESIN
Identifiers & Physical Properties
| CAS No. | 30525-89-4 |
|---|---|
| Molecular formula | CH2O |
| Average molar mass | 30.026 g/mol |
| Monoisotopic mass | 30.01056468 g/mol |
| SMILES | C=O |
| InChIKey | WSFSSNUMVMOOMR-UHFFFAOYSA-N |
| PubChem CID | 712 |
| ChEMBL | CHEMBL1255 |
| ChEBI | CHEBI:16842 |
| EC No. | 200-001-8 |
| DTXSID | DTXSID7020637 |
Chemical & Physical Properties
| XLogP | 1.2 |
|---|---|
| Topological polar surface area | 17.1 |
| Hydrogen bond donors | 0 |
| Hydrogen bond acceptors | 1 |
| Rotatable bonds | 0 |
| Heavy atoms | 2 |
| Formal charge | 0 |
| Complexity | 2 |
| Melting point | 120-170 °C (lit.) |
| Boiling point | 107.25°C (rough estimate) |
| Density | 0.88 g/mL at 25 °C (lit.) |
| Vapor density | 1.03 (vs air) |
| Vapor pressure | <1.45 mm Hg ( 25 °C) |
| Refractive index | 1.4540 (estimate) |
| Flash point | 158 °F |
| Storage conditions | 2-8°C |
| Solubility | chlorophenol above 70°C: solublesparingly soluble |
| Physical state | prilled |
| Color | White to off-white |
| pH | 5.5 (H2O, 20℃)(saturated solution) |
| Odor | odor of formaldehyde |
| PH Range | 4 - 5.5 |
| Explosive limits | 7-73%(V) |
| Merck | 14,7025 |
| BRN | 102769 |
| Dielectric constant | 4.0(Ambient) |
| Stability | Stable. Incompatible with strong acids, organic acids, strong oxidizing agents, oxides, alkalies, strong bases, amines. Combustible. Dust may form an explosive mixture with air. Liberates poisonous gases on combustion. |
| InChI | 1S/CH2O/c1-2/h1H2 |
| InChIKey | VHWYCFISAQVCCP-UHFFFAOYSA-N |
| SMILES | [O-]#[C+H2] |
| Indirect Additives used in Food Contact Substances | PARAFORMALDEHYDE |
| FDA 21 CFR | 175.105176.170177.1210 |
| EWG's Food Scores | 4 |
| FDA UNII | Y19UC83H8E |
| EPA Substance Registry System | Paraformaldehyde (30525-89-4) |
| UNSPSC Code | 12352114 |
| NACRES | NA.25 |
| GHS pictogram | GHS02,GHS07,GHS08 |
| Signal word | Danger |
| GHS hazard statements | H302+H332-H315-H319-H370-H317-H334-H341-H335-H412-H228 |
| GHS precautionary statements | P501-P273-P272-P260-P270-P202-P240-P210-P201-P241-P271-P264-P280-P284-P302+P352-P370+P378-P337+P313-P305+P351+P338-P308+P311-P362+P364-P333+P313-P301+P312+P330-P304+P340+P312-P403+P233-P405 |
| Target organs | Respiratory system |
| Personal protective equipment (PPE) | Eyeshields, Faceshields, Gloves, type P3 (EN 143) respirator cartridges |
| Hazard symbols | Xn,F |
| Risk statements (R) | 31-43-40-36/37/38-20/22-41-37/38-42/43-20/21/22-11 |
| Safety statements (S) | 36-45-36/37/39-26-24-22 |
| UN transport number | UN 2213 |
| Water hazard class (WGK) | 3 |
| RTECS number | RV0540000 |
| Autoignition temperature | 572 °F |
| TSCA inventory status | TSCA listed |
| Hazard class | 4.1Acute Tox. 4 InhalationAcute Tox. 4 OralCarc. 1BEye Dam. 1Flam. Sol. 2Muta. 2Skin Irrit. 2Skin Sens. 1STOT SE 3 |
| Packing group | III |
| Customs code | 38084090 |
| Storage class | 4.1B - Flammable solid hazardous materials |
| Hazardous substances data | 30525-89-4(Hazardous Substances Data) |
| Toxicity | LD50 orally in Rabbit: 592 mg/kg |
| Limited quantities | 5.0 Kg (11 lbs) (solid) |
| Excepted quantities | Max Inner Pack (30g or 30ml) and Max Outer Pack (1Kg or 1L) |
Safety & Regulations
| Personal protective equipment (PPE) | Eyeshields, Faceshields, Gloves, type P3 (EN 143) respirator cartridges |
|---|---|
| Water hazard class (WGK) | 3 |
| TSCA inventory status | TSCA listed |
| RTECS number | RV0540000 |
| UN transport number | UN 2213 |
| Customs code | 38084090 |
| Toxicity | LD50 orally in Rabbit: 592 mg/kg |
| Risk statements (R) | 31-43-40-36/37/38-20/22-41-37/38-42/43-20/21/22-11 |
| Signal word | Danger |
| GHS pictogram | GHS02,GHS07,GHS08 |
| Hazard symbols | Xn,F |
| Safety statements (S) | 36-45-36/37/39-26-24-22 |
| Hazard class | 4.1Acute Tox. 4 InhalationAcute Tox. 4 OralCarc. 1BEye Dam. 1Flam. Sol. 2Muta. 2Skin Irrit. 2Skin Sens. 1STOT SE 3 |
| Storage class | 4.1B - Flammable solid hazardous materials |
| Packing group | III |
| Target organs | Respiratory system |
| GHS hazard statements | H302+H332-H315-H319-H370-H317-H334-H341-H335-H412-H228 |
| Limited quantities | 5.0 Kg (11 lbs) (solid) |
| Excepted quantities | Max Inner Pack (30g or 30ml) and Max Outer Pack (1Kg or 1L) |
| Autoignition temperature | 572 °F |
| GHS precautionary statements | P501-P273-P272-P260-P270-P202-P240-P210-P201-P241-P271-P264-P280-P284-P302+P352-P370+P378-P337+P313-P305+P351+P338-P308+P311-P362+P364-P333+P313-P301+P312+P330-P304+P340+P312-P403+P233-P405 |
Applications & Uses
Uses
Paraformaldehyde is used as a fumigant, a disinfectant and in the manufacture of synthetic resins like melamine resin, phenol resin and polyacetal resin. It is also used in cell culture. It also serves as a fixative in electron microscopy. It is also used in the preparation of formalin fixatives for tissues or cells. To use the chemical as a fixative, it must be converted to the monomer formaldehyde by heating as formaldehyde is the active chemical in fixation.
General Description
Paraformaldehyde appears as a white solid with a light pungent odor. A linear polymer of formaldehyde of formula HO(CH2-O)xH where x averages about 30. Soluble in water when x is less than 12; higher polymers are not immediately soluble. Slow dissolution in water proceeds by means of hydrolysis to give fragments of lower x. Flammable, although may take some effort to ignite. Flash point 158 °F. Used in fungicides, bactericides, and in the manufacture of adhesives. A hazard to the environment. Immediate steps should be taken to limit spread to the environment.
Preparation & Synthesis
Preparation
Paraformaldehyde [30525-89-4] was first produced in 1859. This polymer, at first mistakenly called dioxymethylene and trioxymethylene, consists of a mixture of poly(oxymethylene) glycols HO-(CH2O)n-H with n=8-100. The formaldehyde content varies between 90 and 99 % depending on the degree of polymerization n (the remainder is bound or free water). It is an industrially important linear polyoxymethylene.Paraformaldehyde is prepared industrially in continuously operated plants by concentrating aqueous formaldehyde solutions under vacuum conditions. At first, colloidal, waxy gels are obtained, which later become brittle. The use of a fractionating column through which gases were passed dates from about 1925.Paraformaldehyde is currently produced in several steps which are carried out at low pressure and various temperatures. Highly reactive formaldehyde is produced under vacuum conditions starting with solutions that contain 50-100 ppm of formic acid and also 1-15 ppm of metal formates where the metals have an atomic number of 23-30 (e.g., Mn, Co, and Cu). The solutions are processed in thin-layer evaporators and spray dryers.