How Can We Use Bleach Solution as a Disinfectant?
Different Ways of utilizing Bleach Solution as a Disinfectant
Have you heard about Javel Water? Most readers may not have the slightest idea about it. Indeed, you must have heard about bleach. Well, Javel water or Eau de Javel was the first bleach that was commercially available. The active ingredient used in bleach is sodium hypochlorite. It was after 1820 that disinfection using hypochlorites became famous and was widely used. Bleach is considered one of the most effective disinfectants. This article will explore bleach and its application as a disinfectant.
What is Bleach?
The active ingredient of bleach is sodium hypochlorite about 5.25% in concentration. It is a disinfectant that is strong enough to destroy various pathogens, including bacteria, fungi, protozoan, and viruses. It does so by denaturation of the protective & building protein molecules of the pathogens. Due to its low cost, ability to destroy a wide range of pathogens, and availability, bleach solutions are used as a disinfectant for domestic as well as industrial applications.
Commercially, bleach is available as 5.25% sodium hypochlorite as an active ingredient. For household purposes, bleach can be diluted with water for necessary disinfection. This inexpensive disinfectant when diluted with the appropriate amount of water, produces high level disinfectant, intermediate level disinfectant, and low level disinfectant.
Refer to the following table to know more about the preparation of respective bleach solutions and their uses:
The type of Disinfectant |
Dilution ratio |
Preparation instructions |
Uses |
Contact time with the surface for effective disinfection |
High level disinfectant |
1:10 |
10 mL (2 teaspoons) of Bleach solution in 100 mL of water |
Mainly used for industrial applications primarily public healthcare. |
10 minutes |
Intermediate level disinfectant |
1:50 |
10 mL (2 teaspoons) of Bleach solution in 500 mL of water |
Disinfection of bathrooms & toilets. Disinfection of frequently used surfaces (with high pathogen count). Disinfection of surfaces and articles that are stained by blood and excretions. |
1 to 2 minutes |
Low level disinfectant |
1:500 |
5 mL (1 teaspoon) of Bleach solution in 2500 mL of water |
Disinfection of household items & surfaces with frequent contact with food, especially in the kitchen. It can be used for general household disinfection too. |
At least 1 minute. |
Curious individuals can check out our dedicated blog on high level disinfectants.
FAQ - Does bleach eliminate the novel coronavirus?
During the COVID-19 pandemic, bleach was widely used to disinfect. According to the CDC (Centers for Diseases Control and Prevention), using bleach is highly recommended for disinfection of contaminated areas. So, the answer is yes, bleach can eliminate the novel coronavirus.
What to do before the preparation of the Bleach solution?
Before diluting the bleach, get hold of all the handy equipment. These would be measuring equipment, PPE, and cleaning equipment. Measuring equipment can be any tool that can be used to measure water & bleach. It can be a spoon, a cup, or a bottle. One must ensure that there is no direct contact with bleach, and appropriate PPE must be used. The PPE that one should don includes a respirator, hand gloves, and safety goggles. Cleaning equipment includes wipes, mops, spraying equipment, brushes, mug, and bucket.
Check out our blog on PPE for eye protection.
How to prepare Bleach solution?
Before beginning the disinfection with the help of bleach solution, begin cleaning the surface, especially dirty surfaces with soap, detergent, or any other cleaner. Now, disinfection using bleach should be done following the instructions mentioned by the bleach manufacturer. Don necessary PPE and get hold of cleaning & measuring equipment. Ensure that there is proper ventilation. It could be done by keeping windows open.
Depending on the type of disinfectant you are preparing, add bleach (5.25% sodium hypochlorite) accurately. For the ratio & proportion, refer to the above-mentioned table. Preferably use well-calibrated measuring devices to add bleach to the water. It helps to minimize errors.
If the concentration of sodium hypochlorite deviates from 5.25%, then consider the following equation -
Amount of Bleach = 5.25/Concentration of the sodium hypochlorite in bleach * Amount of the bleach that would have been added if the concentration of the sodium hypochlorite was 5.25
For example if the concentration of sodium hypochlorite in bleach is 2.5%, then from the formula, the amount of bleach is 5.25/3.5*100 mL = 150 mL. The formula is applicable for concentrations greater than 5.25 as well.
While adding & mixing bleach with water, ensure that proper precautions are taken. Don a respirator that will protect you from the irritating chlorine & other fumes, which can cause a great deal of trouble. If required wear a body protective PPE as well. There should be no contact of bleach with the skin, so hand gloves are highly preferred. Use cold water only! Hot water is strictly a NO for bleach. Hot water can negatively impact the disinfection properties of sodium hypochlorite.
How Can We Use Bleach Solution as a Disinfectant?
- Clean the surface using a cleaning agent like soap or detergent.
- Rinse with water.
- Apply bleach solution on the surface using cleaning equipment like wipes or a mop.
- Allow the bleach solution on the surface for a stipulated contact time.
- Allow air to dry.
Precaution while disinfecting using a Bleach solution
- Always follow the instructions mentioned by the manufacturer on the label.
- When diluting bleach, ensure that there is no mixing with any other chemical.
- Please ensure that a respirator is donned throughout the process of dilution.
- Always ensure that the dilution of bleach is done with proper ventilation.
- Use bleach with 3% to 9% of sodium hypochlorite. If the concentration is not in the range, then don’t use them. These bleach products are not fit for disinfection.
- For the preparation of high level disinfectants, intermediate level disinfectants, and low level disinfectants, try to follow the above-mentioned table for the ratios & proportions for bleach dilution.
- Always allow the bleach solution to have a contact time as mentioned in the table. The surface should be wet for the whole period of contact time.
- Avoid using bleach on metals & painted surfaces.
- The effectiveness of diluted bleach stays for about a day but it is recommended to use diluted bleach as soon as possible.
- Bleach should be properly stored in a dry place away from sunlight.
- Bleach loses its effectiveness and expires in a year.
You can check out more precautions on the blog working safely with bleach.
Conclusion -
Bleach has been widely used for many years as a disinfectant. For household purposes, bleach should be diluted and then used. Bleach has an active ingredient called sodium hypochlorite which is majorly responsible for the destruction of pathogens. In this article, various points are related to the preparation of bleach solution and precautions while using & preparing it.