Formaldehyde

 Formaldehyde was first reported by the Russian chemist Aleksandr Butlerov (1828-1886), but it was conclusively identified by August Wilhelm von Hofmann.

NTP 10th Report on Carcinogens. IARC Cancer Review: Group 2A IMEMDT    IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man . 7 (1987),p. 211.(World Health Organization, Internation Agency for Research on Cancer,Lyon, France.: ) (Single copies can be ordered from WHO Publications Centre U.S.A., 49 Sheridan Avenue, Albany, NY 12210) ; Human Inadequate Evidence IMEMDT    IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man . 29 (1982),p. 345.(World Health Organization, Internation Agency for Research on Cancer,Lyon, France.: ) (Single copies can be ordered from WHO Publications Centre U.S.A., 49 Sheridan Avenue, Albany, NY 12210) ; Animal Sufficient Evidence IMEMDT    IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man . 29 (1982),p. 345.(World Health Organization, Internation Agency for Research on Cancer,Lyon, France.: ) (Single copies can be ordered from WHO Publications Centre U.S.A., 49 Sheridan Avenue, Albany, NY 12210) . EPA Genetic Toxicology Program. Reported in EPA TSCA Inventory. EPA Extremely Hazardous Substances List.

OSHA PEL: TWA 0.75 ppm; STEL 2 ppm
ACGIH TLV: CL 0.3 ppm (sensitizer); Suspected Human Carcinogen
DFG MAK: 0.5 ppm (0.6 mg/m³); Confirmed Animal Carcinogen with Unknown Relevance to Humans
NIOSH REL: (Formaldehyde) Limit to lowest feasible level
DOT Classification:  9; Label: None (UN 2209); DOT Class: 3; Label: Flammable Liquid (UN 1198)

For occupational chemical analysis use OSHA: #ID-102 or NIOSH: Formaldehyde (Oxazolidine), 2502; (Chromotropic Acid), 3500.

Formaldehyde (CAS NO.50-00-0) is the simplest aldehyde, ans it exists in water as the hydrate H₂C(OH)₂. Aqueous solutions of formaldehyde are referred to as formalin. Formaldehyde(50-00-0) is an intermediate in the oxidation (or combustion) of methane as well as other carbon compounds, e.g. forest fires, in automobile exhaust, and in tobacco smoke. In the pure form, Formaldehyde in the pure form is a gas with a boiling point of -21°C but is unstable and readily trimerizes to trioxane or polymerizes to paraformaldehyde. Formaldehyde is stable only in water solution, commonly 37 to 56% formaldehyde by weight and often with methanol (3 to15%) present as a stabilizer.

Physical properties about Formaldehyde are: (1)ACD/LogP: 0.35; (2)ACD/LogD (pH 5.5): 0.35; (3)ACD/LogD (pH 7.4): 0.35; (4)ACD/BCF (pH 5.5): 1.09; (5)ACD/BCF (pH 7.4): 1.09; (6)ACD/KOC (pH 5.5): 36.93; (7)ACD/KOC (pH 7.4): 36.93; (8)#H bond acceptors: 1; (9)Index of Refraction: 1.235; (10)Molar Refractivity: 6.536 cm³; (11)Molar Volume: 43.84 cm³; (12)Polarizability: 2.591 10-24cm³; (13)Surface Tension: 12.6099996566772 dyne/cm; (14)Density: 0.685 g/cm³; (15)Flash Point: -75.062 °C; (16)Enthalpy of Vaporization: 22.308 kJ/mol; (17)Boiling Point: -19.501 °C at 760 mmHg; (18)Vapour Pressure: 3463.82006835938 mmHg at 25°C

Preparation of Formaldehyde: Formaldehyde is produced solely from methanol by using a silver catalyst or a metal oxide catalyst. Either process can be air oxidation or simple dehydrogenation.
2CH₃OH + O₂ → 2HCH=O + 2H₂O
CH₃OH → HCH=O + H₂
Those two reactions occur simultaneously in commercial units in a balanced autothermal reaction because the oxidative reaction furnishes the heat to cause the dehydrogenation to take place. In the process, fresh and recycle methanol are vaporized, superheated, and passed into the methanol-air mixer. Atmospheric air is purified, compressed, and preheated to 54 °C in a finned heat exchanger. The products leave the converter (a water-jacketed vessel containing the catalyst) at 620 °C and at 34 to 69 kPa absolute. About 65 percent of the methanol is converted per pass. Temperatures are on the order of 450 to 900 °C and there is a short contact time of 0.01 second. The reactor effluent contains about 25% formaldehyde, which is absorbed with the excess methanol and piped to the make tank. The latter feeds the methanol column for separation of recycle methanol overhead, the bottom stream containing the formaldehyde and a few percent methanol. The water intake adjusts the formaldehyde(50-00-0) to 37% strength (marketed as formalin). The catalyst is easily poisoned so stainless-steel equipment must be used to protect the catalyst from metal contamination.

Uses of Formaldehyde: Formaldehyde is a common building block for the synthesis of more complex compounds and materials. As a disinfectant and biocide: as it kills most bacteria and fungi (including their spores), an aqueous solution of formaldehyde can be useful as a disinfectant . It is also used as a preservative in vaccines. In photography: Formaldehyde can be used in low concentrations for process C-41 (color negative film) stabilizer in the final wash step. Tissue fixative and embalming agent: Formaldehyde solutions are used as a fixative for microscopy and histology. Formaldehyde-based solutions are also used in embalming to disinfect and temporarily preserve human and animal remains.

When you are using this chemical, please be cautious about it as the following:
Wear suitable protective clothing and gloves;
Use only in well-ventilated areas;
In case of accident or if you feel unwell, seek medical advice immediately (show label where possible);
Wear suitable protective clothing, gloves and eye/face protection;

You can still convert the following datas into molecular structure:
(1)InChI=1S/CH2O/c1-2/h1H2;
(2)InChIKey=WSFSSNUMVMOOMR-UHFFFAOYSA-N;
(3)SmilesC=O

The toxicity data is as follows: