About Formalin. Formaldehyde (a.k.a. Methanal) is an organic compound naturally occurring, at ambient temperature, as a colorless gas with a strong pungent odor and is highly flammable. Formaldehyde is the simplest aldehyde in existence and its name comes from its relation and similarities to formic acid. It was first discovered in 1859, however, it began being industrially viable to produce at the beginning of the twentieth century. Due to its relatively low cost, a great variety of uses in chemical reactions, as well as elevated purity, Formaldehyde has become one of the world’s most important research and industrial chemicals.

Formaldehyde present in the environment can derive from natural sources, such as fires and other natural sources of combustion, or anthropogenic sources such as power plants, factories, incinerators and emissions of vehicles not equipped with catalytic converters. It is also one of the volatile compounds formed in the early stages of decomposition of plant residues in soil and occurs naturally in fruits and other foods.

Formaldehyde is very flammable (flash point as 63°C) and can be corrosive to some materials. It has also been described by the US National Toxicology Program as a known human carcinogen. Formalin should be transported in hermetically closed containers, preferably consisting of stainless or lined carbon steel. It can also be transported in vessels made of aluminum, enamel, or polyester resin, but iron, copper, nickel, and zinc alloys must not be used for this end. With decreases in temperature or increases in concentration, aqueous Formaldehyde solutions tend to precipitate paraformaldehyde. On the other hand, higher temperatures lead to formic acid formation. To counter these effects, the addition of stabilizers, such as methanol, ethanol, urea, and melamine, can be made to these solutions.

The commercial production of Formaldehyde consists mostly of two main processes that use methanol as feedstock. These processes are oxidation-dehydrogenation with a silver catalyst, and complete oxidation with a metal oxide catalyst. To a lesser extent, Formaldehyde can also be produced from the oxidation of methane or the hydrogenation of carbon monoxide. Raw materials and the respective production processes employed in the manufacturing of Formalin are listed below.

The uses and applications of Formalin may vary according to its specification. The main forms of Formalin are anhydrous (99.85%); aqueous solution (37-50 wt% Formalin); uninhibited (methanol free); and inhibited (maximum 16 wt% methanol).