Question

When using ethyl alcohol or isopropyl alcohol as a disinfectant, the strength of the solution must be at least:

a) 25%
b) 50%
c) 75%
d) 70%

Answer 1

The strength of the solution when using ethyl alcohol or isopropyl alcohol as a disinfectant must be at least 70% to be effective at inhibiting microbial growth.

Step-by-step explanation:

When using ethyl alcohol or isopropyl alcohol as a disinfectant, the strength of the solution must be at least 70%. Alcohols like ethyl alcohol (ethanol) and isopropyl alcohol (isopropanol) are commonly used as disinfectants because they denature proteins and disrupt membranes in microorganisms, inhibiting their growth. It is important to note that alcohol solutions that are too strong, such as 100% alcohol, are less effective than solutions with a concentration of around 70% because higher concentrations coagulate surface proteins and prevent effective penetration of cells.