Hexamethylenetetramine or methenamine is a heterocyclic organic compound with the formula C6H12N4. This white crystalline compound is highly soluble in water and polar organic solvents. It has a cage-like structure similar to adamantane. It is useful in the synthesis of other chemical compounds, e.g., plastics, pharmaceuticals, rubber additives. It sublimes in vacuum at 280 °C. Hexamethylenetetramine is prepared industrially by reacting formaldehyde and ammonia. The reaction can be conducted in gas phase and in solution.

Paraformaldehyde (PFA) is the smallest polyoxymethylene, the polymerization product of formaldehyde with a typical degree of polymerization of 8–100 units. Paraformaldehyde commonly has a slight odor of formaldehyde due to decomposition. Paraformaldehyde is a poly-acetal. Paraformaldehyde forms slowly in aqueous formaldehyde solutions as a white precipitate, especially if stored in the cold. Formalin actually contains very little monomeric formaldehyde; most of it forms short chains of polyformaldehyde. A small amount of methanol is often added as a stabilizer to limit the extent of polymerization.

Formaldehyde is a naturally-occurring organic compound with the formula CH2O. It is the simplest aldehyde and is also known by its synonyms name formalin or methanal. The common name of this substance comes from its similarity and relation to formic acid. Formaldehyde is an important precursor to many other materials and chemical compounds. It is mainly used in the production of industrial resins, for the manufacture of particle boards and in the coating industry.

Hexamethylenetetramine or methenamine is a heterocyclic organic compound with the formula C6H12N4. This white crystalline compound is highly soluble in water and polar organic solvents. It has a cage-like structure similar to adamantane. It is useful in the synthesis of other chemical compounds, e.g., plastics, pharmaceuticals, rubber additives. It sublimes in vacuum at 280 °C. Hexamethylenetetramine is prepared industrially by reacting formaldehyde and ammonia. The reaction can be conducted in gas phase and in solution.

Paraformaldehyde (PFA) is the smallest polyoxymethylene, the polymerization product of formaldehyde with a typical degree of polymerization of 8–100 units. Paraformaldehyde commonly has a slight odor of formaldehyde due to decomposition. Paraformaldehyde is a poly-acetal. Paraformaldehyde forms slowly in aqueous formaldehyde solutions as a white precipitate, especially if stored in the cold. Formalin actually contains very little monomeric formaldehyde; most of it forms short chains of polyformaldehyde. A small amount of methanol is often added as a stabilizer to limit the extent of polymerization.

Formaldehyde is a naturally-occurring organic compound with the formula CH2O. It is the simplest aldehyde and is also known by its synonyms name formalin or methanal. The common name of this substance comes from its similarity and relation to formic acid. Formaldehyde is an important precursor to many other materials and chemical compounds. It is mainly used in the production of industrial resins, for the manufacture of particle boards and in the coating industry.