Does Chlorine Kill Coronavirus?
Summer's here, and everyone is wondering if it's safe to go back in the water.
Now that temperatures are rising across the country, people are looking for ways to cool off—and stay safe from the novel coronavirus. Travel may never get back to normal after the coronavirus, but beaches and community pools are beginning to reopen in some states, and families are pulling the covers off their backyard pools. The promise of sweet relief from the heat, along with a little relaxation and a sense of summer normalcy, is almost palpable. Still, a lot of people (understandably) have questions about how the virus may or may not spread while they’re splashing around.
Water? No worries
Research has found that the family of germs known as coronaviruses can survive in water for days or even weeks, but surviving and having the ability to infect are two different things. The U.S. Centers for Disease Control and Prevention (CDC) says there is no evidence that the novel coronavirus—the one that causes the pandemic illness known as Covid-19—can actually spread or infect people who come in contact with it in the water. (But can you catch coronavirus from swimming?)
Chlorine kills viruses
Chlorine is the most commonly used disinfectant in public and private pools, and for good reason. It has a long history of successfully killing viruses in the water, including SARS, another type of coronavirus. The CDC says, similarly, that “proper operation and disinfection of pools, hot tubs, and water playgrounds should kill the virus that causes Covid-19.”
Testing the waters
Pools that use chlorine should be tested at least twice daily to make sure the disinfectant remains at an effective level. The CDC recommends maintaining a free chlorine concentration of at least 1 part per million in swimming pools, and at least 3 ppm in hot tubs. Pools should also strive for a pH of 7.2 to 7.8. Any higher, the CDC says, and the chlorine is not as successful at killing germs; any lower, and the pool’s pipes are likely to corrode. (That’s also the range that keeps swimmers’ eyes and skin from feeling overly irritated.) While there’s no data yet on how quickly the chlorine will work against the coronavirus, it generally takes less than a minute for chlorine to kill some bacteria, and less than an hour with other microbes.
Showering before entering the pool helps the chlorine do its job. The CDC also notes that other body secretions in the water, like pee, poop, and sweat, use up the free chlorine that’s normally available to kill germs. By reducing how much work the chlorine has to do against those unsavory elements, it can fight harder against coronavirus and other germs. If you’re visiting a pool that doesn’t have a shower or restroom readily available, consider the possibility that the chlorine might have to work harder there. And if you’re smelling a strong odor, it’s probably the opposite of too much chlorine.
Do a spot check
Basic pool maintenance can also limit the spread of coronavirus and other germs. Do a quick check before entering a pool to make sure drains (usually at the deep end) are visible and securely covered—and not clogged with hair, bandages, or other debris. You can even test the chlorine and pH levels yourself before you get in. Pool test strips are available at most hardware and pool supply stores. Test them out with your home tap water first, so you know how to use and interpret them before dunking them in the pool. (Here are 17 hidden pool dangers you need to know.)
Keep your distance
Even if the water is sparkling clean, you could still get sick. That’s because people, not surfaces, are still the biggest threat when it comes to spreading coronavirus. For that reason, people who haven’t been quarantining together should still maintain a social distance of six feet—in and out of the water. People should also continue to wear masks any time they are not in the water. (But not in the water, where a wet mask could be dangerous if it obstructs your breathing.)
Forget what you learned in kindergarten
These days, not sharing is caring. Bring your own pool noodles, swim goggles, inflatables, and towels, and clean them after every use. Likewise, don’t share food or utensils with people you haven’t been quarantined with. The CDC advises that everything and anything else that gets touched frequently—think handrails, lounge chairs, tabletops—should be sanitized regularly. If you’re swimming at a public pool, you may want to stash some disinfectant wipes in your bag and give any surface a once-over before touching it, just in case.
Have a ball at the beach
Going to the beach, if it’s permitted in your state, can be a healthy option, too. The risk of coronavirus transmission is lower outdoors, according to research from China published in the BMJ, and wide-open spaces at the beach can make it easier to avoid breathing other people’s air.
But many of the guidelines for safe beach enjoyment are the same as for pools: Stay at least six feet apart from other people on land, and wear a face-covering when that’s not possible. (And maybe bring an extra mask in case one gets wet.) Following this advice is especially important in potentially crowded areas like boardwalks, snack bars, and restrooms.
Be a game-changer
Be mindful of the activities you participate in at the beach. While beach volleyball might seem like the perfect weekend exercise, it can get pretty germy with all those hands on the same ball, not to mention the inevitable body bumps and slams with other participants. More solitary pursuits, like running along the shoreline or snorkeling with your own equipment, have lower risks.
Keep your crew small, too, wherever you may swim. The general advice to limit gatherings to ten people or fewer still applies. If the pool is crowded or the parking lot for the beach is packed, reconsider your plans. A run through the sprinkler or a dash down a backyard water slide might be just as refreshing and with lower risk. If you do find yourself around other people from outside your home —who may have the virus even if they don’t exhibit any symptoms—limit the amount of time you spend with them. The longer you’re exposed to them, the greater your chances of becoming infected.
Keep it to yourself
Regardless of whether your swimming adventures take you to the pool or the ocean, everyone should follow basic hygiene practices. For example, don’t ever spit, blow your nose or cough into the water. And, of course, if you’re sick, stay home.
- U.S. Centers for Disease Control and Prevention: "Considerations for Public Pools, Hot Tubs, and Water Playgrounds During COVID-19"
- Water Research: "Survival of surrogate coronaviruses in water"
- U.S. Centers for Disease Control and Prevention: "Disinfection & Testing'
- Journal of Virological Methods: "Study on the Resistance of Severe Acute Respiratory Syndrome-Associated Coronavirus"
- U.S. Centers for Disease Control and Prevention: "Visiting Parks and Recreational Facilities"
- USAToday: "Swimming during the pandemic: What the CDC wants you to know before you hit the pool"
- BMJ: "Indoor transmission of SARS-Cov-2"
- U.S. Centers for Disease Control and Prevention: "Public Health Guidance for Community-Related Exposure"