With each passing day, scientists are learning more about the properties of the novel coronavirus that causes COVID-19. The spread of the disease has been rapid, reaching most countries in the world, and all 50 of the United States.
Today we'll look at the latest information about how this coronavirus functions, including survival time in the air and on surfaces. Then we'll review the measures you can take to protect yourself and those around you.
What We Currently Know About The Novel Coronavirus
The novel coronavirus is formally named SARS-CoV-2, and is a never-before-seen coronavirus that causes a disease called COVID-19. Other known coronaviruses cause the common cold and the diseases MERS and SARS that emerged over the past twenty years. Humans have no immunity to this new virus, allowing it to spread rapidly across the globe.
SARS-CoV-2 transmits through human respiratory droplets and contact with infected persons. The name SARS-CoV-2 stands for severe acute respiratory syndrome coronavirus 2. The virus is highly transmissible, due in part to its ability to survive outside the human body. Scientists have been conducting studies to determine how long it can survive on different surfaces and in the air.
A study published in the New England Journal of Medicine examined the aerosol and surface stability of SARS-CoV-2. They found that the virus persists as follows:1
- In aerosols: three hours
- On copper: four hours
- On cardboard: 24 hours
- On stainless steel: two to three days
- On polypropylene plastic: three days
Polypropylene is a type of plastic used for food containers, toys, and many other everyday products. Aerosols are solid particles small enough to suspend in the air. The scientists don't have a definitive answer as to why the virus survives such differing lengths of time on different surfaces.
These results are useful for making safety decisions. They indicate that people can acquire the virus through the air and after touching contaminated objects. The long life of the virus on steel and plastic underscores the importance of regularly sanitizing frequently used surfaces and objects.
The 24-hour lifespan of the virus on cardboard has not translated into infections from packages that arrive in the mail. This is likely because shipping conditions kill the virus. Nonetheless, it's important to sanitize everything that enters your home.
While the virus persists for three hours in aerosol droplets, air movement tends to prevent the virus from hanging in the air for long periods. In a study conducted in Singapore, researchers tested the hospital rooms of infected patients and all air samples came back negative.2
In that study, 13 of 15 other room sites came back positive for the virus, including an air vent, suggesting that the virus is traveling via aerosol particles to locations beyond the reach of the infected patient. However, when the rooms of infected patients were tested after cleaning, all the room sites came back negative.2
These study results have been brought into question by a study that examined outbreaks on cruise ships. Researchers found traces of SARS-CoV-2 on surfaces in the cabins of the cruise ship the Diamond Princess as long as 17 days after passengers left, but before the cabins had been disinfected. This finding, although not reproduced in controlled studies, underscores the importance of disinfecting to destroy any trace of the virus.3
SARS-CoV-2, the novel coronavirus that causes COVID-19 can survive on tiny particles suspended in the air for three hours, on copper for four hours, on cardboard for 24 hours, on stainless steel for two to three days, and on polypropylene plastic for three days. Even though a study found traces of the virus lingering in cruise ship cabins for up to 17 days, the results were obtained prior to disinfection. Regular disinfecting is critical to prevent the spread of the virus.
What You Can Do To Prevent Infection And Spread
These results confirm the importance of the social distancing, disinfecting, and isolation practices currently recommended.
Here are the best practices for minimizing contact with the virus:
- Disinfect objects you bring into your home, including boxes, groceries, delivery containers, etc.
- Remove outer layers of clothing when returning home.
- Remove shoes and socks (to avoid slipping!) when you come in from outside and place them in a bag by the door.
- Clean and disinfect frequently touched objects and surfaces using household cleaning spray or wipes.
- Wash your hands when you get home, before you eat or prepare food, and after you cough or sneeze.
- Cough or sneeze into a tissue then throw the tissue away.
- Stay inside your home as much as possible.
- Continue to avoid physical proximity to others – if you go out, remain six feet away from other people at all times.
- Avoid touching your face.
- If you start to feel sick, call a medical professional.
How To Effectively Disinfect Surfaces
Disinfecting frequently touched surfaces and objects is a simple and effective means of reducing your risk of contracting SARS-CoV-2. A study published in the Journal of Hospital Infection examined the results of 22 studies on the persistence of other coronaviruses on surfaces and strategies for disinfecting them.4
According to their results, disinfectants with 62-71% ethanol, 0.5% hydrogen peroxide or 0.1% sodium hypochlorite (bleach) can efficiently inactivate coronaviruses within a minute.
The CDC has stated that diluted household bleach solutions, alcohol solutions containing at least 70% alcohol and most EPA-registered common household disinfectants are effective at disinfecting surfaces against the coronavirus.5
The CDC recommends wearing disposable gloves when cleaning and disinfecting surfaces.
Discard gloves after cleaning. If your gloves are reusable, designate a pair exclusively for cleaning or disinfecting surfaces for SARS-CoV-2. Wash your hands after you remove gloves and store them in a separate bag for future use.
If surfaces are dirty, they should be cleaned using a detergent or soap and water prior to disinfection.
You can use a diluted household bleach solution if it's appropriate for the surface. Follow the label's instructions for application and ventilation. Always check the expiration date and make sure the product hasn't expired.
Prepare a bleach solution by mixing five tablespoons (1/3rd cup) bleach per gallon of water or four teaspoons bleach per quart of water.
For soft surfaces such as carpeted floor, rugs, and drapes, clean with the appropriate cleaners indicated for use on these surfaces. For launderable items including clothes, follow washing instructions at the warmest appropriate water setting and dry completely. Be sure to also disinfect laundry hampers.
Never mix chemicals or cleaning substances together, as they often combine to form deadly gases or highly corrosive acids.
Household cleaners, disinfectants with 70% alcohol, and diluted bleach solutions are effective for disinfecting surfaces. Wear disposable gloves and ventilate the area. Follow label instructions for any products. Laundering clothes and other soft washables will disinfect them.
What This Means To You
Take the simple and effective precautions detailed above to destroy the novel coronavirus and prevent it from spreading. Clean frequently touched surfaces often, since the virus can survive many hours on most materials. We know that maintaining a distance from other people reduces the chances that the virus will reach us in the air.
Follow the disinfecting protocols at home, and reduce your potential for exposure by only leaving the house when necessary. Together we can mitigate the spread of the virus and lessen the impact of the COVID-19 health crisis.