COVID-19: Cleaning frequently asked questions

Information about general cleaning during the COVID-19 response.

Last updated: 7 August 2020

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What is the difference between cleaning and disinfecting?

Cleaning means to physically remove germs (bacteria and viruses), dirt and grime from surfaces using a detergent and water solution. It is an essential first step in any disinfection process.

Disinfecting means using chemicals to kill germs on surfaces. It’s important to clean before disinfecting because dirt and grime can reduce the ability of disinfectants to kill germs. The disinfectant concentration and contact time are also critical for effective surface disinfection.


How to clean and disinfect

Gather your equipment such as cleaning and disinfecting agents, cleaning cloths and mops, and protective equipment to wear (eg, gloves) before you start cleaning.

Clean surfaces first with detergent and warm water. Anything labelled as a detergent will work. Disinfectants should only be used once the surface is fully cleaned because dirt and grime can reduce the effectiveness of a disinfectant to kill germs, including the COVID-19 virus.

Disinfectants come with instructions from the manufacturer describing how to safely use them. Make sure you give the disinfectant time to work – disinfectants require dwell time to be effective at killing germs. Dwell time is the amount of time the disinfectant should remain wet on a surface before drying. If no time is specified on the manufacturer’s directions, leave the disinfectant for ten minutes before drying the surface with a clean cloth. 

When cleaning it is good to remember two general principles:

  • top to bottom: start cleaning surfaces higher up and work your way to the floor. This method ensures that any particulates or debris fall to the floor which will be cleaned last
  • clean to dirty: start cleaning with the cleanest surface first, progressively moving towards the dirtiest surface (eg, toilets).

When floors are cleaned, they should be left dry before walking on to reduce the risk of slips and falls.


What products can be used to disinfect?

You can use hypochlorite disinfectants (bleach), products that contain ≥ 70% alcohol, or products that state on the label that they have antiviral activity, meaning they can kill viruses.

If using bleach, mix with water following the dilution instructions provided by the manufacturer. Fresh bleach solution should be made every 24 hours. If the solution is not prepared and used as described in the instructions, it is unlikely to be effective.


Can I use a product that claims to clean and disinfect at the same time?

Yes, some products can be used for both cleaning and disinfecting, which can save time and effort. If using these products, make sure that you read and follow the instructions on the label to ensure they work effectively.


What is the difference between household grade disinfectant and hospital grade disinfectant?

Hospital grade disinfectants must meet government standards for use in health care settings. A household or commercial grade disinfectant must also meet government standards, but the testing is not as comprehensive as it is for hospital grade disinfectants and the standards to be met are lower. The label on the product will say if it is a hospital grade disinfectant.

Household or commercial grade disinfectants are suitable for use in places that are not health care settings.


Which areas should be cleaned and disinfected, and how often?

Any surfaces that are frequently touched should be prioritised for cleaning, such as door handles, light switches, horizontal surfaces including tables and counter tops, phones, EFTPOS machines, touch screens, and workplace amenities (such as toilets). Any surfaces that are visibly dirty should also be cleaned as soon as they are identified, regardless of when they were last cleaned. 

Buildings that are accessed by the public should be cleaned at least every day. If your building has many customers or others entering each day, more frequent cleaning is recommended.


What is meant by a frequently touched surface?

A frequently touched surface is a surface that is touched multiple times each day by the same person or different people. Door handles and push plates, light switches, and handrails are examples of frequently touched surfaces in public thoroughfare areas or hallways.


How do I use cleaning and disinfecting chemicals safely?

Know what chemicals you are handling. Read the product label before use, and make sure you understand the instructions and follow all recommendations. You may need to wear personal protection items.

Make sure you only use chemicals in well ventilated areas, as many release fumes that can irritate your eyes and lungs and cause nausea or headaches. Be especially careful when diluting concentrated cleaners. Be aware of potential irritation from the cleaning chemicals to passers-by.

Never mix different chemicals together, unless the product label explicitly tells you to do so. Some common cleaning chemicals react when combined to create toxic gas that can be fatal if inhaled.


Do I need to wear protective equipment when cleaning?

For routine cleaning (when there has not been a known case of COVID-19), you should wear appropriate gloves and any other protective items recommended by the manufacturer of the products you are using.


What if a known case of COVID-19 has been in the building?

The building will need to be cleaned and disinfected as soon as possible. Generally, the cleaning and disinfecting that occurs after a case of COVID-19 can be done with the same products that are usually used for cleaning and disinfecting.

Contact the local public health unit or DHB IPC Service for further advice about what needs to be done. Read more about cleaning following a confirmed case of COVID-19.


How should soft or porous surfaces be cleaned?

Follow your usual procedures for cleaning or laundering soft or porous materials like carpet, rugs or seating.


Are there any cleaning methods I shouldn’t use?

You should avoid any cleaning methods that may spread the virus or create droplets, such as using pressurised water, pressurised air (including canned air cleaners), dry cloth and dusters.


Is ‘fogging’ an effective disinfectant method?

Physically cleaning surfaces with detergent and warm water, followed by disinfection when needed, is the most effective way to kill the virus that causes COVID-19. Fumigation or wide-area spraying (known as ‘disinfectant fogging’) does not clean surfaces effectively and there is little evidence that it is effective at killing COVID-19. Additionally, if fogging is not done correctly, it can expose workers and others to hazardous chemicals.


Is a sanitiser a disinfectant?

A sanitiser is a chemical that is designed to kill some, but not all, bacteria and some viruses that can cause disease in humans or animals. These chemicals are not as strong as disinfectants, which makes them safe to use on skin. For example, provided your hands are not soiled, when you should wash your hands with soap and water, a hand sanitiser with ≥60% alcohol will kill the COVID-19 virus. If you’re disinfecting a hard surface or object use a disinfectant not a sanitiser.


Does heating or freezing kill the virus?

Extreme heat will destroy the virus that causes COVID-19 but is not recommended as a general disinfection method. Viruses are generally resistant to the cold and can remain viable if frozen.


Can I make my own disinfectant?

Store-bought disinfectants meet government standards, so you know they will work. However, if you don’t have store bought disinfectant available, you can prepare a disinfecting solution using bleach and water. If using bleach, mix with water, following the dilution instructions provided by the manufacturer. Fresh bleach solution should be made every 24 hours. Do not use products such as vinegar, baking soda, essential oils, mouthwash or saline solution – these will not kill COVID-19.


Will an antibacterial product kill COVID-19?

Most disinfectants will kill both bacteria and viruses. To be called a disinfectant wipe or solution it must kill both bacteria and viruses. Antibacterial products are designed specifically to kill bacteria, however, COVID-19 is caused by a virus rather than by bacteria, so unless it has an antiviral claim, an antibacterial product may not be effective.

Detergent and warm water are suitable for cleaning surfaces and should be used prior to using a disinfectant.

For cleaning hands, regular soap and warm water, then thorough drying with a clean towel/paper towel is effective.


Can I use the same disinfecting wipe on multiple surfaces?

No. Disinfecting wipes are designed to be used on a single surface and then disposed in a rubbish bin (not flushed down the toilet). If you use a disinfecting wipe on multiple surfaces it will lose its effectiveness and may even transfer germs from one surface to another. If the product you are using is not a combined (2-in-1) cleaning and disinfecting wipe, clean the surface first.

Ensure you read and follow the directions that come with the disinfecting wipes.

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