Which statement about glutaraldehyde is true?

• A. It is effective against spores when used at 0.5% for 1 hour
• B. It is effective against acid-fast bacilli, vegetative bacteria, spores, fungi, and viruses at 2% for 10 hours
• C. It inhibits cell wall synthesis
• D. In a concentration of 2%, soaked for 10 hours; is effective against acid-fast bacilli, other vegetative bacterial cells, spores, fungi, and viruses

Answer: (D)

Glutaraldehyde acts as a chemical sterilant when used at the right concentration and exposure time by alkylating proteins and nucleic acids, causing cross-linking that inactivates a wide range of organisms. At 2% concentration with a long contact time of about 10 hours, it can achieve sterilization of heat‑sensitive instruments, killing not only vegetative bacteria but also acid-fast bacilli, spores, fungi, and viruses. This long immersion is essential for spores to be inactivated; shorter times or lower concentrations don’t reliably achieve sterilization. Its action is through protein cross-linking rather than inhibiting cell wall synthesis, which is how some antibiotics work. Therefore, the regimen of 2% for 10 hours best reflects glutaraldehyde’s sterilant, broad-spectrum activity.