For disinfecting surfaces, we can recommend lots of widely available disinfectant sprays such as the Dettol Surface Cleansing Spray. Look out for something that ‘kills 99.9% of germs’ - these products kill viruses, and are thought to be effective against COVID-19.1
But you might now always have a disinfectant to hand.
So we’ve put together a guide on how to make your own disinfectant spray, using some ingredients you probably already have. Regular household bleach can be diluted with water to make an effective disinfectant. If you can't find bleach, we’ve included instructions for disinfecting with hydrogen peroxide. Bleach and hydrogen peroxide aren’t suitable for some delicate surfaces, so we’ve also included an alcohol-based alternative you can use.
Making a bleach-based disinfectant
You will need:
- An empty spray bottle
- Measuring jug
- Household bleach (containing sodium hypochlorite)
- Personal Protective Equipment
To make your disinfectant:
1. Open windows and turn on extractor fans
Bleach fumes can be harmful to your lungs, so open windows and turn on extractor fans to ensure that the room is well ventilated before you begin mixing your disinfectant.2
2. Wash your hands with soapy water for 20 seconds
Before completing any cleaning, you should wash your hands for at least 20 seconds with soapy water. You can view NHS guidance on hand-washing below:
3. Put on protective equipment
Household bleach is an irritant, so make sure that you are wearing Personal Protective Equipment (PPE) before you handle bleach. You should wear a mask, goggles, an apron and rubber gloves while handling and using bleach. Always read the label on your product and follow all instructions to ensure safe use of bleach.
4. Mix your solution
Standard household bleach usually contains 5% sodium hypochlorite, which should be mixed at a dilution of 1:100 with cold tap water.3 If your bleach has a lower concentration, adjust accordingly (i.e. if your bleach contains 2.5% sodium hypochlorite, use twice as much bleach).
5% sodium hypochlorite bleach should be mixed at the following ratios, depending on the size of your bottle:
Screw your lid back on and shake to mix the solution.
5. Handle carefully
Bleach is a powerful chemical, so the following precautions should be taken:
- You should label the bottle containing your bleach solution clearly
- Do not leave bleach in reach of children at any time
- Avoid mixing any bleach solution with other chemicals
- Do not store your bleach solution - mix fresh when required 4
How to use your disinfectant
1. Ensure that your space is well ventilated
Open windows, and turn on extractor fans before you use your disinfectant.
2. Wear protective equipment
Rubber gloves should be worn while applying the disinfectant, and you may also wish to wear a mask, apron and goggles.
3. Clean your surfaces
Before disinfecting, you should first clean your surfaces with warm soapy water and a clean cloth.
4. Apply your disinfectant
Spray your disinfectant directly onto your surface. To adequately disinfect, allow a contact time of at least 10 minutes.5 Bleach is corrosive, and should not be applied to any sensitive surfaces such as marble or granite. If concerned about the suitability of bleach, test on a discrete area first.
5. Wipe surfaces
Once the contact time has elapsed, wipe your surface with a clean damp cloth.
6. Clean or dispose of protective equipment
Non-disposable cleaning equipment, such as cloths and aprons, should now be hand- or machine-washed at high temperatures (60C+).
Any disposable cleaning equipment should be placed in the household waste.
Alternatives to bleach:
In addition to bleach, there are other household chemicals that can be used to disinfect your surfaces and protect against viruses.
Disinfecting with hydrogen peroxide
You can still buy hydrogen peroxide, which can be used directly at a 3% concentration, and is effective against viruses.6 Here’s a link to one that’s still in stock.
How to disinfect with hydrogen peroxide
1. Ensure that your space is well ventilated
Open windows, and turn on extractor fans before you use your disinfectant.
2. Wear rubber gloves
Rubber gloves should be worn while using hydrogen peroxide, and you may also wish to wear a mask and apron.
3. Clean your surfaces
Before disinfecting, you should first clean your surfaces with warm soapy water and a clean cloth.
4. Transfer your hydrogen peroxide to a spray bottle
Transfer enough hydrogen peroxide to cover your surfaces into an empty spray bottle.
5. Spray hydrogen peroxide directly onto your surface
Spray your hydrogen peroxide directly onto your surface to disinfect. 3% hydrogen peroxide has been shown to kill viruses with a contact time of 6-8 minutes, so it’s best to allow a contact around 10 minutes for disinfection.7
Hydrogen peroxide is acidic, so should not be applied to sensitive surfaces, such as marble or granite. If unsure of suitability, test hydrogen peroxide on a discrete area before disinfecting your surfaces.
6. Wipe surfaces
After allowing sufficient contact time, you should wipe your surfaces again with a clean, damp microfiber cloth.
7. Clean or dispose of protective equipment
Non-disposable cleaning equipment, such as cloths and aprons, should now be hand- or machine-washed at high temperatures (60C+).
Any disposable cleaning equipment should be placed in the household waste.
Disinfecting with rubbing alcohol
You can still purchase rubbing alcohol, also known as isopropyl alcohol, which has also been shown to be effective against viruses, including the influenza virus and rhinovirus.8 Alcohol should be used at concentrations of 60-90% to maximise virucidal effectiveness.9 Here’s a link to one that’s still in stock.
How to disinfect with rubbing alcohol
1. Ensure that your space is well ventilated and safe
Open windows, and turn on extractor fans before you get started. Alcohol is highly flammable and can be toxic, so ensure the room is well ventilated and there are no naked flames in the vicinity.
2. Clean your surface
Begin by cleaning your surface with a clean cloth and warm, soapy water.
3. Transfer your rubbing alcohol to a spray bottle
Transfer enough rubbing alcohol to cover your surfaces into an empty spray bottle.
4. Spray rubbing alcohol directly onto your surface
To disinfect, spray your rubbing alcohol directly onto your surface. Allow a contact time of ten minutes.
Do not use rubbing alcohol on varnished surfaces or furniture, as this could strip the surface of its varnish. Alcohol can also damage rubber and plastics.
5. Wipe surfaces
Once the contact time has elapsed, wipe your surface with a clean damp cloth.
6. Clean or dispose of protective equipment
Non-disposable cleaning equipment, such as cloths and aprons, should now be hand- or machine-washed at high temperatures (60C+).
Any disposable cleaning equipment should be placed in the household waste.
Staying safe while using chemicals
Bleach, hydrogen peroxide and rubbing alcohol are all strong chemicals and should be handled with care. Observe the following guidelines to avoid damage to persons or property:
- Keep chemicals out of reach of children
- Wear appropriate PPE while handling and using chemicals
- Only use chemicals in a well-ventilated space
- Clearly label any spray bottles containing chemicals
- Never mix chemicals
- Always read the labels on products carefully and follow all instructions
References
1. https://www.nea.gov.sg/our-services/public-cleanliness/environmental-cleaning-guidelines/guidelines/interim-list-of-household-products-and-active-ingredients-for-disinfection-of-covid-19
2. https://medlineplus.gov/ency/article/000143.htm
3. https://www.ncbi.nlm.nih.gov/books/NBK214356/table/annexg.t1/?report=objectonly
4. https://www.ncbi.nlm.nih.gov/books/NBK214356/
5. https://www.ncbi.nlm.nih.gov/books/NBK214356/table/annexg.t1/?report=objectonly
6. https://www.journalofhospitalinfection.com/article/S0195-6701(20)30046-3/fulltext
7. https://www.cdc.gov/infectioncontrol/guidelines/disinfection/disinfection-methods/chemical.html#Hydrogen
8. https://www.ncbi.nlm.nih.gov/books/NBK214356/
9. https://www.cdc.gov/infectioncontrol/guidelines/disinfection/disinfection-methods/chemical.html