(Q4) Shelf Life of Formaldehyde

Question 1

Factors Influencing Shelf Life of Formaldehyde

Answer 1

• Temperature
• Time
• pH
• Light

Question 2

Temperature

Answer 2

• Increased temperatures may convert formaldehyde to formic acid
• Decreased temperature favor polymerization
• Ideal temperature for preservatives is in the 60’s and 70’s

Question 2

Time

Answer 2

• Polymerization occurs over time
• Methanol is added as an anti-polymerization agent
• 2-5 years is the average shelf life of fluids

Question 3

pH

Answer 3

• Strongly alkaline solutions cause decomposition of the formaldehyde
• Highly acidic solutions promote polymerization

Question 4

Light

Answer 4

• Light may cause color changes due to the oxidation of the fluid components
• May also speed up the rate of polymerization (sunlight oxidizes chemicals which cause polymerization)
• Use tinted containers to prolong shelf life