Paraformaldehyde

Paraformaldehyde

Structural formula of paraformaldehyde

Paraformaldehyde is a polymer of formaldehyde with the chemical formula (CH_O)_, where n is typically 8-100. It is a white, crystalline solid that is used in various applications, particularly in biology and medicine as a fixative for tissue samples.

Chemical Properties

Paraformaldehyde is a polyacetal, which means it is a polymer formed from the repeated condensation of formaldehyde molecules. It is insoluble in water and has a characteristic formaldehyde odor. Upon heating, paraformaldehyde depolymerizes to release formaldehyde gas, which is the basis for its use as a fumigant and disinfectant.

Uses

Paraformaldehyde is widely used in histology and pathology for the fixation of biological tissues. It is preferred over formaldehyde solutions because it can be stored as a solid and dissolved in water to produce formaldehyde solutions of desired concentrations when needed.

Fixation in Histology

In histological applications, paraformaldehyde is used to preserve tissue samples by cross-linking proteins, which stabilizes the tissue structure and prevents degradation. This process is crucial for preparing samples for microscopy and other analytical techniques.

Disinfectant and Fumigant

Paraformaldehyde is also used as a disinfectant and fumigant due to its ability to release formaldehyde gas upon heating. This property makes it useful for sterilizing equipment and surfaces in laboratories and medical facilities.

Safety and Handling

Paraformaldehyde is a hazardous material and should be handled with care. It can release formaldehyde gas, which is a known carcinogen and can cause irritation to the respiratory system, skin, and eyes. Proper personal protective equipment (PPE) such as gloves, goggles, and masks should be used when handling paraformaldehyde.

Related pages

• Formaldehyde
• Histology
• Fixative
• Carcinogen