Which of the following substances can act as both an antiseptic and a disinfectant depending on its concentration?

Step-by-step solution

Phenol can act as both an antiseptic and a disinfectant depending on its concentration. A 0.2 % solution of phenol acts as an antiseptic, whereas a 1 % solution of phenol acts as a disinfectant. Analgin and aspirin are analgesics, and sodium pentothal is an anesthetic. Answer: Phenol