Office disinfection during flu season: which surfaces and how often

During flu season, it is usually enough to clean surfaces that many people touch more often in the office: door handles, light switches, shared keyboards, desks, the kitchenette and toilets. In addition, ventilate regularly and have soap at the sinks. Add disinfection selectively where someone has been ill or where several people take turns at one spot, always only after washing the surface and observing the contact time from the label.

This article does not replace a regular cleaning plan. It describes only what to add to it in flu season. You can find the basic list of tasks in the article daily, weekly and monthly office cleaning checklist.

How flu spreads in the office

According to the National Institute of Public Health (SZÚ), flu is most often transmitted through the air, by droplets produced when breathing, talking, coughing, blowing the nose and sneezing. It is also transmitted via contaminated hands and objects, because the virus can survive for a certain time outside the human body. As examples, SZÚ mentions telephone receivers and used tissues (SZÚ, Chřipka).

The US CDC adds that infection can spread when a person touches a contaminated object and then touches their eyes, nose or mouth (CDC, Healthy Habits to Prevent Flu).

This gives an order of priorities. First come ventilation, hand washing and people who are ill not coming to work. Surface cleaning is an important supplement, but it has no effect on droplets in the air.

Cleaning or disinfection?

The CDC states that cleaning with soap or detergent and water alone removes most germs from surfaces. Disinfection then kills those that remain, and it is carried out only on a cleaned surface. According to the CDC, regular cleaning is enough for routine prevention, and it recommends disinfection mainly where people have clearly been ill (CDC, When and How to Clean and Disinfect a Facility).

For an office, this means:

• Cleaning more often: all frequently touched surfaces throughout the season.
• Targeted disinfection: the workstation and shared items of a colleague who went home with symptoms, places affected by coughing or sneezing, and toilets when several people in the team are ill.

The difference is covered in more detail in the article the difference between cleaning and disinfection.

Which surfaces and how often

The CDC lists door handles, handrails, lift buttons, touchscreens, toilet fixtures, desks, counters and writing instruments, among others, as frequently touched surfaces. The following table is an indicative suggestion. Adjust the frequency to the number of people and how the premises are used.

A personal desk used by only one person can usually be handled by its user. It is enough to provide them with wipes or a cloth and a suitable cleaning product.

Disinfection step by step

Equipment:

• disposable gloves (and other protective equipment, if the label specifies it),
• a cleaning product or detergent and water,
• a disinfectant suitable for the given surface, with a stated effect on viruses,
• microfibre cloths or disposable wipes, ideally colour-coded for toilets and the kitchenette.

1. Read the label. Find out which surfaces the product is intended for, whether and how it is diluted, what the contact time is and what protective equipment to use.
2. Ventilate. Before disinfecting, the CDC recommends opening windows and doors or increasing the output of the ventilation system. Put on gloves.
3. Wash first. Clean the surface with soap or detergent and water. Disinfection does not work reliably on a dirty surface.
4. Prepare the solution. If the product is diluted, use room-temperature water according to the CDC, unless the label states otherwise. Measure, do not estimate.
5. Apply and leave to act. The surface must stay wet for the whole contact time.
6. Finish according to the label. If the label requires rinsing (typically for surfaces that come into contact with food), rinse the surface with clean water.
7. Clean up after yourself. Wash or throw away the cloths, take off the gloves and wash your hands.

Safety when working with chemicals:

• Never mix products. The CDC warns that mixing can be dangerous. In particular, never combine products containing chlorine with acids or ammonia. You can find details in the article which cleaning products should never be mixed.
• Do not decant products into unlabelled bottles, and store them out of the reach of children and animals.
• Test a new product first in a hidden spot, especially on varnished wood, plastics and upholstery.

Contact time: why it matters

The US EPA explains contact time as the time for which a product must remain on the surface in order to work, and the surface should be visibly wet for that entire time (EPA, Selected EPA-Registered Disinfectants). The contact time varies by product and by microorganism, so always look for it on the label. This also applies to disinfectant wipes.

The most common mistake is to spray the product and wipe it dry immediately. This approach merely cleans the surface. If the surface dries before the contact time has elapsed, apply more of the product.

The EPA lists apply to the US market. In the Czech Republic, follow the product label, which should state what the product acts against and for how long it must act.

Keyboards, telephones and other electronics

For electronics, the CDC recommends following the device manufacturer's instructions and considering washable covers, which are easier to clean. In general:

• switch off or unplug the device before cleaning,
• do not spray the product directly on the device; apply it to a cloth, which should be only damp,
• make sure that liquid does not get into openings or between the keys,
• for touchscreens, check in the manual which products the surface can tolerate.

Ventilation

The National Institute of Public Health lists regular ventilation of rooms among the basic hygiene measures against flu, alongside frequent and correct hand washing and the use of disposable tissues and towels. Government Regulation No. 361/2007 Coll., in Section 41(1), stipulates that sufficient air exchange by natural, forced or combined ventilation must be ensured at the workplace to protect employees' health (Government Regulation No. 361/2007 Coll.).

In practice, short intensive ventilation during the day, airing the meeting room after a meeting and checking that the ventilation system is running in the set mode all help. If it is managed by the building owner, check the settings with them.

What an employer or office manager can arrange

• Soap and disposable towels at every sink and a bin for used tissues.
• Hand sanitiser where water and soap are not at hand, for example at the entrance or in the meeting room. The CDC recommends it as a substitute when soap and water are not available.
• Rules for people who are ill. The CDC recommends staying at home when ill. Agree a clear procedure for taking leave or working from home, so that people with symptoms do not come to the office.
• Vaccination. SZÚ generally recommends that employers offer employees discounted or free flu vaccination.
• Seasonal adjustment of cleaning. Add more frequent cleaning of contact points and rules for hot-desking to the cleaning plan.

If cleaning is provided by an external company, agree with them on a seasonal extension of the scope and on which products will be used. Úklid 1-2-3 offers this type of cleaning as part of its office cleaning service. An indicative overview of what affects the price is on the page how much office cleaning costs.

An employer's obligations regarding the working environment are governed by the Labour Code and implementing regulations. This text is general information, not legal advice. Check your specific situation with an occupational health and safety specialist or with the regional public health authority.

When someone in the office falls ill

1. The person with symptoms should go home, ideally without stopping in shared areas.
2. Ventilate the room where they worked.
3. First clean, then disinfect their desk, keyboard, mouse, telephone and shared items they touched, following the procedure above.
4. Also go over the routes they took: handles, the kitchenette and the toilet.
5. Throw used tissues and wipes into a bin, ideally one with a lid, and wash your hands.