Nomenclature
CAS number: 50-00-0
Methanal; oxomethane; oxymethylene; methylene oxide; formic aldehyde; methyl aldehyde.
CH
2O; mol wt 30.03.
C 40.00%, H 6.71%, O 53.28%.
HCHO.
Description and references
Formed by incomplete combustion of many organic
substances. Present in coal and wood smoke, esp in smoke as produced
for smoking ham and fish. Found in the atm, esp over large cities.
Prepd commercially by catalytic vapor phase oxidation of methanol
using air as the oxidizing agent and heated silver, copper, alumina,
or coke as catalysts. Process using molybdenum iron oxide catalyst:
Allyn et al., US 2812309 (1957) and US 2849492 (1958 to Reichhold Chem.). Prepn of stable formaldehyde
by heating low molecular polyoxymethylenes with P2O5: DE 1070611 (1959 to BASF). Mfg processes: Faith, Keyes & Clark's Industrial Chemicals, F. A. Lowenheim, M. K. Moran, Eds. (Wiley-Interscience, New York,
4th ed., 1975) pp 422-429. Prepn of semicarbazone: M. Pomerantz et al., J. Org. Chem. 47, 2217 (1982). Toxicity data: H. F. Smyth et al., J. Ind. Hyg. Toxicol. 23, 259 (1941). Vapor-pressure relationship studies: R. Spence, W.
Wild, J. Chem. Soc. 1935, 506. Carcinogenicity study: J. A. Swenberg et al., Cancer Res. 40, 3398
(1980). Assessment, regulation and evaluation of carcinogenicity:
F. Perera, C. Petito, Science 216, 1285 (1982). Review: H. R. Gerberich et al., in Kirk-Othmer Encyclopedia
of Chemical Technology vol. 11 (John Wiley
& Sons, New York, 4th ed., 1994) pp 929-951. Review of toxicology:
H. d'A. Heck et al., Crit. Rev.
Toxicol. 20, 397-426 (1990); of oral toxicity:
P. Restani, C. L. Galli, ibid. 21, 315-328 (1991).
Properties
Colorless gas at ordinary temp. Pungent suffocating
odor. d 1.067 (air = 1.000). d
420 0.815. mp 118.0°. bp
760 19.5°; bp
400 33.0°; bp
200 46.0°; bp
100 57.3°; bp
60 65.0°; bp
40 70.6°; bp
20 79.6°; bp
10 88.0°. Ignition temp about 300° (572°F).
Flammable, corrosive. Very sol in water, up to 55%; sol
in alcohol, ether. Very reactive, combines readily with many substances,
and polymerizes easily.
See also Paraformaldehyde.
Derivative
Formaldehyde solution.
Nomenclature
Formalin; Formol; Morbicid; Veracur (Typharm). Properties
A soln of about 37% by wt of formaldehyde gas
in water, usually with 10-15% methanol added to prevent polymerization.
This soln is the full strength and also known as Formalin 100% or
Formalin 40 which signifies that it contains 40 grams of formaldehyde
within 100 ml of the soln. Colorless liq; pungent odor. On standing,
esp in the cold, may become cloudy and on exposure to very low temp
a ppt of trioxymethylene is formed. When evaporated, some formaldehyde
escapes, but most of it is changed to trioxymethylene. It is a powerful
reducing agent especially in presence of alkali. In the air it slowly
oxidizes to formic acid. d2525 1.081-1.085. One gallon weighs 9.1
lbs. bp760 96°. nd20 1.3746. Flash pt 60°C (140°F). pH 2.8-4.0. Misc with water,
alcohol, acetone. Keep well closed in a moderately
warm place. LD50 orally in rats: 0.80 g/kg (Smyth).Derivative
Formaldehyde semicarbazone.
Nomenclature
CAS number: 14066-69-4
2-Methylenehydrazinecarboxamide.
C
2H
5N
3O; mol wt 87.08.
C 27.59%, H 5.79%, N 48.25%, O 18.37%.
Properties
Crystals from ethanol, mp 120-121°. uv max (CH3CN): 227 nm (log ε
3.73).Caution
Potential symptoms of overexposure
to formaldehyde are irritation of eyes, nose, throat and respiratory
system; lacrimation; coughing; bronchial spasm. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH
97-140, 1997) p 148. May act as a primary irritant on skin causing
erythmatous or eczematous dermatitis. Sensitization can result. See Patty's Industrial Hygiene and
Toxicology vol. 2A, G. D. Clayton, F. E. Clayton,
Eds. (Wiley-Interscience, New York, 3rd ed., 1981) pp 2637-2646.
Ingestion may cause immediate intense pain in mouth, pharynx and stomach;
nausea, vomiting, hematemesis, abdominal pain, diarrhea; pale, clammy
skin and other signs of shock; difficult urination, hematuria, anuria;
vertigo, convulsions, stupor, coma; death due to respiratory failure.
See Clinical Toxicology of Commercial
Products, R. E. Gosselin et al., Eds. (Williams
& Wilkins, New York, 5th ed., 1984) Section III, pp 196-197.
Formaldehyde gas is reasonably anticipated to be a human carcinogen:
Report on Carcinogens, Eleventh Edition (PB2005-104914, 2004) p III-125.Use
In the prodn of amino, phenolic, and polyacetal
resins, wood products, plastics, fertilizers and foam insulation.
As a textile finish, preservative, stabilizer, disinfectant and antibacterial
food additive. Reagent in synthetic organic chemistry. Reducing
agent. Prevention of polymerization.
Therapeutic Category
Solution as disinfectant.
Therapeutic Category (Veterinary)
Solution as antiseptic; fumigant; has
been used in tympany, diarrhea, mastitis, pneumonia, internal bleeding.
Keywords
Formaldehyde Solution: Antiseptic/Disinfectant; Aldehydes