Mike Bowen can’t remember exactly when the calls started. As the co-owner and executive vice president of Texas mask manufacturer Prestige Ameritech, he says the last few months have been a blur. His office phone and cell now ring practically nonstop, and Bowen says he often ends the day with more than 150 missed calls and hundreds of emails. (During one 40-minute interview, the company’s office line rang so often it was difficult to tell when a new call began.)

Bowen’s voicemail inbox is littered with messages from hospitals and medical distributors in dire need of surgical masks, N95 respirators, and other forms of essential protective gear his company makes. There are also emotional pleas from elderly people and fearful parents of immunocompromised children desperate for a way to limit their potential exposure to the novel coronavirus, as the pandemic sweeps around the globe. And then there’s the stream of callers looking to capitalize on the global shortage of personal protection equipment by buying masks in bulk to sell at a markup on ecommerce platforms like Amazon and eBay, a practice that the companies have recently curbed due to a wave of price-gouging.

In an attempt to keep up with demand, Prestige Ameritech’s management team is working 80-hour weeks, bringing previously idle machines online, and hiring and training dozens of new employees to augment its staff of around 100. Back in what Bowen calls the “peacetime,” before the pandemic, Prestige Ameritech made roughly 250,000 masks a day. Now the company has ramped production up to 1 million masks a day.

But even that isn’t enough. “Since February 1, we’ve had to turn down orders for 100 million masks or more a day on average,” Bowen says. “Sometimes, we turn down 200 million or 300 million [masks] a day. It’s kind of surreal.”

US mask manufacturers say they are experiencing unprecedented demand. With the pandemic and trade restrictions pressuring already-overwhelmed global supply chains, companies are struggling to keep up. Like much of the mask manufacturing industry, industrial giant 3M has been ramping up production since January–including expanding the output of its US based factories, hosting job fairs, and hiring employees on the spot. Yet some US hospitals are still unable to obtain new shipments of surgical masks and N95 respirators.

“There’s a really, really high demand for respirators and really all other products being used in response to the coronavirus to help treat and protect people,” Jennifer Ehrlich, communications manager for 3M told WIRED. “It’s more demand than any one company can supply, and we expect it to remain high for the foreseeable future.”

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One reason is that over the last two decades China has become the primary manufacturer for the world’s masks and respirators. When the virus swept through China in late 2019 and early 2020, the country’s increased need for masks dealt a double whammy to the global supply. The US is particularly reliant on China for masks and other medical gear. According to the Department of Health and Human Services, 95 percent of surgical masks and 70 percent of respirators used in the US are made overseas, and China is one of the biggest producers.

“We were already in the middle of a bad flu season, and now we’re having a pandemic in the middle of the flu. Couple that with with American hospitals gearing up, people panic buying, and China now cutting off a good portion of the masks they send to the US–it’s a perfect storm,” says Bowen.

That’s led to a lot of hard decisions for manufacturers. Faced with hundreds of millions of orders a day, and a limited number of masks, Prestige Ameritech decided to sell only to hospitals, rather than the general public, and has prioritized working with medical centers that will sign five-year contracts, to reduce the likelihood that the company will have to lay off all its new employees once the pandemic subsides.

The policy is rooted in history. The last time the country faced a comparable mask shortage was during the 2009 H1N1 outbreak. To meet increased demand, Prestige Ameritech hired hundreds of new employees and expanded its manufacturing capabilities. But after the outbreak died down, Bowen says that most hospitals that had relied on Prestige Ameritech went back to Chinese suppliers, which typically sell masks and respirators for less than it costs him to produce.