Coronavirus can survive on nonliving surfaces like glass, wood, metal, etc for up to 72 hours. Thus it is important to disinfect surfaces like elevator walls, doors, bells, etc from time to time.
Calcium Hypochlorite or Sodium hypochlorite, commonly known as Bleaching Powder is a powerful disinfectant and can work very well for protection against Coronavirus. Bleaching powder is readily available in supermarkets and many grocery shops too in packets of 100g – 1Kg. Many industries use it too and thus could be easily available with industrial chemical suppliers. Bleach is also used in cleaning swimming pools.
Calcium hypochlorite and Sodium hypochlorite, when dissolved with water, releases hypochlorous acid. Hypochlorous acid is highly active against all bacterial, viral, and fungal human pathogens and a small amount of HOCl can kill these microorganisms in a short time period.
How to prepare
Raw materials: Pure Bleaching powder, water, wooden stick or spoon to stir, bucket or containers, ph strips
Note: Avoid using things made of metals in any of the above processes.
Quantity: Buy pure bleaching powder from the market. For home use, a quantity of 500g is sufficient for multiple uses. For large scale use in societies, apartments, offices, etc bulk quantities can be bought.
Put on gloves or simply cover your hands with polythene. Mix 15g of bleaching powder in 10 liters of water. Slowly pour the powder while stirring the solution. If fumes start coming out, wait for a few seconds before pouring more. While preparing this, the water temperature is recommended to be below 25-degree celsius. In the case of hotter places, to maintain temperature, ice cubes could be used. Avoid direct sunlight or hot temperatures while preparing the solution.
After adding the powder and stirring the solution, leave it to settle for 30 mins and then collect it in a closed container leaving any material settled at the bottom. The solution prepared is good for use up to 4 hours. However, we recommend use within 2 hours.
The solution thus prepared can then be used for cleaning the surfaces, mopping the floor, etc. Simply spray the solution on surfaces or wet a cloth and wipe on the surface. Leave it to dry. It could also be sprayed on containers, parcels, packages received from outside.
For apartments, it can be used to wipe walls and switches of lifts every 4 hours for added precaution.
1) Spray bottle 2) Mop 3) Wiping Cloth 4) using in lift
Safety Precautions: While preparing the solution, do not inhale the fumes and avoid fumes getting in your eyes. It is advised to use gloves, goggles and wear a mask while handling the preparation of this solution. The solution is safe even if it comes in touch with the skin but can cause some irritation or allergy. In such cases simply wash that part of the skin with running water.
References and Detailed SOP – https://drive.google.com/file/d/1J8n5xqih_9jH6t1u-HL3WZ7pySqEdo0D/view
The solution in the same proportions can be prepared in bulk for disinfecting common or public places like hospitals, apartments, offices, etc. For example, mix 150g of pure bleaching powder in 100litres of water. Use that to spray around the building, or washing the floors, etc.
The spraying can be done using a spray machine and the surface left to dry on its own.
Note: Make sure the excess water is washed down through the drains.
Use of the solution for human disinfection.