Forget Millennial Pink walls, beautifully landscaped outdoor living spaces, and fancy backsplashes. With tensions mounting between the U.S. and nuclear-armed North Korea, there's another home amenity that's in raging demand right now: air filtration systems designed to screen out deadly contaminants.

After all, who needs new patio furniture if the apocalypse is near?

Ever since North Korea's recent missile test and a war of words between its leadership and President Donald Trump, business has been booming (sorry) at bunker and safe room companies across the country. And their go-to items these days are the filters that provide air or water protection to increase the odds of survival if there's a nuclear, biological, or chemical attack.

As it turns out, it's not just the stereotypical preppers living off the grid and stockpiling supplies and ammunition to get ready for mass annihilation who are purchasing these systems. More and more otherwise ordinary folks are now looking into buying the potentially life-saving devices, according to the companies that sell them.

For the first time since the height of the Cold War with the Soviet Union, Americans are taking the threat of nuclear war seriously, says Don Mann, a former Navy SEAL who has written 14 books, including one on survival tactics.

"We could be hit with a nuclear attack," he says bluntly.

Many owners of disaster-prep businesses say it's the busiest they've been since right before the presidential election, when clients fearing civil unrest wanted to hole up with a bunch of weapons. Now customers are more worried about a cataclysmic attack, so they're putting their money where their fear is: They are clamoring for military-grade air filters, which start at around $5,000 to $6,000.

"It's a wise decision to get prepared ahead of time," says Salt Lake City–area prepper Chrystle Poss, who runs the Survival Spot blog. "If [disaster] happens—and it will happen without any warning—there won't be any time to run to the store and get the things that you need."

Who's worried about a nuclear attack? Everyone

If you want to survive a nuclear attack, you need an air filtration system. American Safe Room

The demographics and political profile of disaster-preparedness paraphernalia customers are changing dramatically.

"We have more of the Democrat side making purchases now," says Clyde Scott, owner of Rising S Bunkers in Murchison, TX. "And we have Hollywood calling."

His company's luxury bunkers start at $45,000. (Hey, you might as well survive the end of the world in style.)

The air systems bring in air from the outside and force it through carbon and HEPA filters to remove dangerous contaminants and particles. They are, in the simplest terms, essentially very high-tech vacuum cleaners. The devices also expel the carbon dioxide that people exhale, which can build up in a contained space and, in toxic environments, become deadly.

Many models run on solar and/or battery power. If all else fails, most can be hand-cranked. But, if disaster does strike, they're good for only one attack—not multiple ones over days, weeks, or months. After each "event," the filters inside most systems need to be changed. That can run $500 or higher for each replacement pack.

Even those who can't afford to build a bunker deep underground are taking precautions. Many are turning their basements or closets into safe rooms that they fortify themselves, says Mike Peters, president of Ultimate Bunker, outside of Salt Lake City. They'll make the spaces airtight, reinforce the walls, put in a pipe to facilitate the flow of air, and install a filtering system.

Water filtration systems are also popular in case the water supply is tainted in an attack. Rising S sells ones that use UV lights to kill bacteria in contaminated water and filter out unwanted particles. They go for about $1,800 and can purify about 5,000 gallons of water.

The Survival Spot's Poss believes sales of the filtration systems will be brisk—at least for the next few weeks. Or until threat levels ratchet up again.

"Everybody gets upset and stocks up on supplies ... and then as the threat is gone, it goes back to business as usual," she says.

You don't need to go off the grid to protect yourself

You don't need to move to the middle of nowhere to prepare for doomsday. Some wealthy urban dwellers who don't have basements or yards for a bunker are opting for safe rooms.

In the biggest cities, the main concern is a dirty bomb that would release nuclear, biological, or chemical gases into the atmosphere, says Tom Gaffney, president of Gaffco Ballistics. His Londonderry, VT–based company installs high-end safe rooms, primarily for the New York City elite.

Those with safe rooms equipped with the filters could conceivably wait out the chaos breathing in purified air until it was safe to go outside again.

But this backup plan doesn't come cheap. Resistant to bullets and forced entry, safe rooms start at $250,000 and go up to about $1.5 million. The filtration systems add an additional $40,000 to the bill. Despite the high price, Gaffney has seen a 60% to 70% increase in calls from potential customers since Trump's "fire and fury" comments.

"It's a sense of a lack of security in the world we live in today" that's driving sales, Gaffney says.

Sales of air filtration systems are on the rise due to the threat from North Korea. American Safe Room

Keep calm and don't panic ... yet

Folks shouldn't freak out and start stocking up on air and water filtration systems just yet, says Mann, the former Navy SEAL and survivalist author. First, North Korean leader Kim Jong Un appears to have backed off from his threats to attack the U.S. territory of Guam as an opening salvo. So things seem to be calming down, at least for the moment.

But regardless of what happens, consumers should realize that the air filtration systems aren't foolproof, Mann says.

"There are all types of other things that can happen, like windows that aren’t sealed, [air that can seep in] underneath doors and by the door hinges," he says. Radioactive fallout could create dust (fatal if inhaled) that could make its way into homes as easily as ants or rodents get in. Filtration systems are "not a fail-safe measure."

Creating breathable air is just one of many, many steps you should be taking if you're really concerned about an attack, says Mann.

"The priority is shelter, food, and water." So you'd better stock up while you can!