Which one of the following is classified as a halogen disinfectant?

Appeared in: JSSH Staff Nurse - 2019

Explanation

Bleach because it is a chlorine-based compound, and chlorine is a member of the halogen group of elements.
Bleach is an aqueous solution of sodium hypochlorite (NaOCl).
Halogen disinfectants, including chlorine and iodine compounds, work by being strong oxidizing agents that destroy the cellular components of microorganisms.
It is a broad-spectrum disinfectant effective against bacteria, viruses, fungi, and spores.

Option A: Alcohol (e.g., ethanol, isopropanol) is classified as an alcohol, not a halogen. It works by denaturing proteins.
Option B: Biguanide (e.g., Chlorhexidine) is its own class of disinfectant. It works by disrupting the cell membrane of microorganisms.
Option D: Phenol and its derivatives (phenolics) are a distinct class of disinfectants that damage cell membranes and denature proteins.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Classification of Disinfectants as background academic context rather than a clinical decision trigger.
Understanding disinfectant classes is crucial for infection control. Using the wrong disinfectant or an incorrect dilution can lead to the failure of decontamination and the spread of healthcare-associated infections (HAIs).
Nurses are responsible for ensuring that appropriate disinfectants are used for specific tasks, such as using a 1:10 bleach solution for a blood spill versus a 1:100 solution for routine cleaning.
What if? If a nurse used an alcohol-based wipe to clean a surface with a large blood spill, it would be ineffective. The organic load of the blood would inactivate the alcohol, and it is not the recommended agent for this purpose, increasing the risk of pathogen transmission.

How to Approach the Question

First, identify the key term in the question: 'halogen disinfectant'. This tells you the question is about chemical classification.
Recall the major classes of disinfectants taught in microbiology and infection control.
Analyze each option and try to place it into a chemical class.
Option A, Alcohol, is its own class.
Option B, Biguanide, is its own class (e.g., chlorhexidine).
Option C, Bleach, is sodium hypochlorite. Recall that chlorine (in hypochlorite) is a halogen element.

Concept Tested & Keywords

Q9zj8kX1eZuVh-09tzqMO5

E6 Parks TextBook of Preventive & Social Medicine part 1 — Subpart A (pp 26-201 of 604) p. 127-129

E6 Pharmacology Katzung 16e p. 1396-1398

Practise the full JSSH Staff Nurse - 2019

Attempt every question from this paper in a timed mock, then review the full solution for each one.