Paraformaldehyde ( Polyoxymethylene ) PFA - 100g

Paraformaldehyde (Polyoxymethylene, PFA)
Other Names: PFA, Polyformaldehyde, Formaldehyde polymer
Chemical Formula: (CH₂O)ₙ
CAS Number: 30525-89-4
Molar Mass: Variable (n ≈ 8–100); often approximated as ~30.03 g/mol per repeating unit
Appearance: White crystalline or powdery solid
Odor: Characteristic pungent, formaldehyde-like odor (due to monomer release)

Paraformaldehyde is a polymerized form of formaldehyde. It consists of linear chains of repeating –CH₂O– units and depolymerizes upon heating or in acidic aqueous solution to release formaldehyde gas. It is commonly used as a source of formaldehyde in various chemical reactions and cross-linking applications.

Chemical and Physical Properties

• Density: ~1.42 g/cm³

• Melting Point: Depolymerizes rather than melts (≈120 °C with decomposition)

• Solubility:

  • Water: Slowly hydrolyzes to formaldehyde in warm or acidic water

  • Solvents: Slightly soluble in alcohol and acetone

• Flash Point: >70 °C

• Stability: Stable when dry; releases formaldehyde gas in humid or acidic environments

• Vapor Pressure: Negligible at room temperature (significant for released formaldehyde)

Applications

Chemical Synthesis

• Source of formaldehyde in condensation reactions (e.g. urea-formaldehyde resins, phenolic resins)

• Used in polymer crosslinking and polymerization initiation

Fixatives and Preservatives (Non-medical)

• Employed in industrial preservation and disinfection processes

Agricultural and Laboratory Use

• Used in synthesis of biocides, pesticides, and reagents

• Commonly used for sample fixation in microscopy and histology (research purposes)

Safety

Signal Word: ⚠️ Danger

Hazard Statements:

• H301: Toxic if swallowed

• H311: Toxic in contact with skin

• H331: Toxic if inhaled

• H314: Causes severe skin burns and eye damage

• H335: May cause respiratory irritation

• H341: Suspected of causing genetic defects

• H351: Suspected of causing cancer

Precautionary Statements:

• P260: Do not breathe dust, gas, or vapors

• P280: Wear protective gloves/clothing/eye/face protection

• P301+P310: IF SWALLOWED: Immediately call a POISON CENTER or doctor

• P305+P351+P338: IF IN EYES: Rinse cautiously with water; remove contact lenses if present

• P403+P233: Store in a well-ventilated place. Keep container tightly closed

• P501: Dispose of contents/container in accordance with local regulations

Handling and Storage

• Handling: Avoid inhalation of dust. Use in well-ventilated areas or fume hoods. Use PPE: gloves, goggles, lab coat, and dust mask or respirator.

• Storage: Store in a tightly sealed container in a cool, dry, and well-ventilated place. Keep away from acids, moisture, and heat sources.

• Decomposition: In humid air or heated conditions, PFA slowly depolymerizes, releasing formaldehyde gas.

Environmental Considerations

Hazardous to aquatic and terrestrial environments if released in large quantities. Avoid release into drains or natural watercourses. Must be disposed of according to hazardous chemical waste regulations.