Los Angeles Mayor Eric Garcetti said free public coronavirus testing will be opened up to workers “on the frontlines,” such as grocery clerks, janitors, city workers and healthcare workers, starting Thursday, April 23.

Previously, tests had only been available to people with symptoms at the centers, which grew from a handful to 34 spanning the county over the past two months.

Garcetti described this latest expansion as a “very important milestone on the road to reopening,” during Wednesday’s briefing on the city’s response to the novel coronavirus crisis.

Garcetti listed the eligible workers as “healthcare professionals, grocery-store workers, first-responders and critical government personnel.”

Workers will need to go through their employers to sign up for the tests, according to the mayor. As of early Wednesday evening, the online application still required that a person have “flu-like symptoms, such as cough, fever, and shortness of breath” before they could sign-up.

The announcement came on a day in which Gov. Gavin Newsom recommended that people without symptoms also be tested. But Garcetti said that the priority for testing of asymptomatic people would be limited, for now to these essential workers.

Garcetti said the public testing sites have the capacity to test 12,200 people a day.

“We wish we could open that up to everybody,” Garcetti said, “but I think we all know that we have firefighters and police officers, doctors, nurses, janitors and hospitals folks that are in grocery stores and pharmacies, that are putting themselves out on the line.

Those workers “interact with so many people that we can make sure that they’re not spreading,” he added.

County public health officials have begun shifting their focus more toward testing asymptomatic people at institutional settings, starting with nursing homes.

In the latest figures released Wednesday, 40% of the deaths countywide have been at such group settings, with many of them at nursing homes.