The ratio of mixing bleaching powder and water for acting as a disinfectant is:

Appeared in: Combined AIIMS - 2020 (Jodhpur, Bhopal, Patna, Raipur)

Explanation

The ratio of 1 part bleaching powder to 99 parts water is the standard for preparing a 1% hypochlorite solution.
A 1% chlorine solution is the widely recommended concentration for general-purpose surface disinfection in healthcare settings.
This concentration effectively kills a broad spectrum of pathogens, including bacteria and viruses, on non-critical surfaces.
It provides an optimal balance between antimicrobial efficacy and safety, minimizing damage to surfaces and risk to personnel.

Option A: A 1:1 ratio would create a thick, unusable paste, not a liquid solution suitable for disinfection.
Option B: A 1:50 ratio creates an approximately 2% solution. This is stronger than necessary for routine environmental disinfection and can be more corrosive to surfaces and irritating to users.
Option D: A 1:1000 ratio creates a 0.1% solution. This is too dilute for effective general surface disinfection and may not kill all harmful microorganisms.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Preparation of Disinfectant Solutions as background academic context rather than a clinical decision trigger.
Correctly preparing disinfectant solutions is a fundamental nursing responsibility for infection prevention and control.
Using an improperly diluted solution can lead to the failure of disinfection, contributing to the spread of healthcare-associated infections (HAIs).
Nurses must educate other healthcare workers and cleaning staff on the importance of correct mixing ratios, contact time, and the need for fresh solutions.

How to Approach the Question

First, identify the core of the question: it's asking for the standard mixing ratio of bleaching powder for disinfection.
Recognize that 'disinfectant' in a general nursing context usually refers to surface disinfection.
Recall the standard concentrations for disinfectants. A 1% solution is a common benchmark for general use.
Convert the given ratios into percentages to evaluate them. A 1:99 ratio corresponds to 1 part in a total of 100 parts, which is 1%.
Eliminate the other options based on practicality (1:1 is a paste) or application (1:1000 is for sanitizing/water treatment, not general disinfection).
Select 1:99 as the most appropriate and widely accepted standard for general disinfection.

Concept Tested & Keywords

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Practise the full Combined AIIMS - 2020 (Jodhpur, Bhopal, Patna, Raipur)

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