Now it’s the critical period to fight COVID-19 epidemic. In addition to staying at home as far as possible, wearing masks, washing hands frequently, ensuring good ventilation, experts also recommend sterilizing cell phone screens, computer keyboards, door knobs, faucets, and keys to prevent the virus from spreading indirectly.

Novel coronavirus is sensitive to ultraviolet light and heat, keeping the temperature at 56 ℃ for 30 minutes, using 75% ethanol, ether, chlorine-containing disinfectant, peracetic acid, chloroform and some other lipid solvents can effectively inactivate the virus. However, improper disinfection products and methods may also bring risks to your health and safety. So in this special period, what should you pay special attention to during disinfection and sterilization? I’ve collected some reference Q&A, let’s have a look.

1. Is the concentration of alcohol the higher the better?

It’s true that the alcohol with low concentration can hardly kill the virus. But the alcohol with a too high level can create a protective layer on the surface of the virus, preventing alcohol from entering the virus body and making it difficult to kill the virus thoroughly.

75% medical alcohol is most effective to kill the coronavirus.

2. Where can 75% medical alcohol be used, and how?

75% medical alcohol can be used in cell phone screens, computer keyboards, door knobs, faucets, keys, thermometers, etc.

When disinfecting the surface of objects such as keys, door handles, keyboards, mice, etc., the alcohol can be put in a small spray bottle and sprayed on the surface of objects with paper towels or alcohol wiping 1-2 times.

Remember to turn off the phone when you disinfect it, and then rub the surface with alcohol wipes.

To disinfect thermometer, you can immerse thermometer completely in 75% alcohol for 1 minute, and shake the water off for further using.

75% medical alcohol can be used to disinfect hands as well. Spray it on the front and back of the hand, then rub them thoroughly to achieve the purpose of disinfection.

3. Is it dangerous to disinfect with alcohol? What should I pay attention to?

Alcohol has a low ignition point and is flammable when exposed to fire or heat. Due to this reason, you can’t spray it in the large area like corridor, conference room, office, etc.

It’s not recommend to spray alcohol to your clothing as well. Otherwise when it’s exposed to open flame or static electricity, combustion may occur.

Fires can also start when the concentration of ethanol in the air is more than 3%, so it is more dangerous to spray alcohol into the air in large quantities than to ignite it directly.

When storing alcohol at ordinary times, it should be divided into small bottles, sealed and stored in a cool, dry, ventilated, dark place, and of course, away from fire.

4. Can I mix several disinfectants?

First of all, 84 disinfectants cannot be mixed with toilet cleaner. This is because the main component of 84 disinfectants is sodium hypochlorite, and the toilet cleaner’s is dilute hydrochloric acid. Once the two contact, the mixing will occur reaction, and produce toxic chlorine gas, which can cause serious damage to our respiratory system, and in severe cases, even lead to death.

In addition, when disinfecting, don’t use 84 disinfectant and alcohol together. The mixing of these two can not only reduce disinfection effect, but also produce the poisonous gas that contains chlorine.

5. Can ultraviolet light effectively kill the novel coronavirus?

The ultraviolet ray with enough intensity can kill virus, but the wavelength of the ultraviolet lamp equipment of household use does not necessarily apply to disinfect, so if your use the purple lamp as disinfect equipment, it may not be effective.

If a special disinfection uv lamp is purchased, the product instructions should be strictly followed during operation to ensure that it is used in an unmanned environment to avoid injuries to eyes and skin, and the toxic and harmful substances such as ozone which may be generated during ultraviolet irradiation.

To sum up, although uv disinfection is useful, it is not recommended for home disinfection.

The outdoor air circulation is very good, and the survival time of the virus in the external environment is very short, so it is not necessary to sterilize the external environment on a large scale.

It is not appropriate to use drones, or hot smoke machines, fog gunners for spray disinfection as well. They will only pollute the environment and cause unnecessary harm to the crowd.

If the environment is directly contaminated by the patient’s vomit, excreta, secretions, etc., the aerosol can be used for disinfection. It is not necessary to conduct disinfection on the ground, the surface of the vehicle and the wheels, etc.

7. Should I disinfect the express?

It’s hard not to order takeout when you’re at home, and it’s impossible not to pick it up when you get a delivery. However, many people are concerned that the deliveryman travels from community to community and comes into contact with many households every day, what if they accidentally catch the virus?

In fact, different viruses have different survival times outside the human body, and the virus attached in the express delivery should have long died. But there’s a chance that the virus infected recently still be alive.

If you’re concerned about indirect contact, you can ask the delivery guy to leave it at the door and wait until he’s gone (it’s safe for both parties to have less contact), then wipe the packaging with alcohol and wash your hands before opening it. You can also wipe the outer packing to reduce the risk.