NEW YORK- Hundreds of grocery store workers have died from the novel coronavirus, despite wearing masks, having their temperatures taken, and stores implementing capacity restrictions meant to keep them healthy and safe.

Supermarkets have resisted banning customers from coming inside, however, union leaders and grocery owners believe it has become too dangerous to let customers browse aisles, coming into close range with workers.

Experts say it's time for large chains to go "dark" to the public and convert to curbside pickup and home delivery for food and other essential goods, CNN reports. 

"Careless customers" are "probably the biggest threat" to workers right now, according to Marc Perrone, president of the United Food and Commercial Workers' union. The union said 85% of its grocery store member workers reported that customers are not practicing social distancing in stores.

"Anything that reduces the need for interaction with the public and allows for greater physical distancing will ultimately better protect grocery workers," said John Logan, professor and director of Labor and Employment Studies at San Francisco State University. "Shuttering stores and repurposing them for pickup and delivery only would be a positive step."

General manager of Takoma Park Silver Spring Co-op in Maryland, Mike Houston, decided to close his grocery store to the public in late March when the state announced a shelter-in-place order and switch to curbside pickup.

"It was clearer that there was no real way to protect my staff and the public, especially as we served 960 people a day on average in a 4,200-square-foot store," Houston said. "I'm unwilling to put grocery store employees, essential though we are, in a position to risk what can be a fatal infection."

Public safety officials are not requiring essential stores to shut down to customers, however, the US Labor Department recommended that retailers start "using a drive-through window or offering curbside pick-up" last week.

The California Department of Industrial Relations said that companies should "encourage customer use of online order and pickup."

Some big grocers are slowly starting to move in this direction. Whole Foods has closed down a store in New York City's Bryant Park area and transitioned it into an online-only store, focused solely on deliveries. Kroger and Giant Eagle have switched a few stores to pickup and delivery-only locations. 

These are just a fraction of stores in their wide networks and most large chains have hesitated to shut down to the public. Instead, they are implementing more limited policies like taking workers' temperatures and restricting the number of customers inside stores at a time.

Companies are asking families to cut back on their trips to the store each week and to shop alone if possible.

City and state governments are stepping in to force stricter measures than the companies have adopted.

Some states require shoppers to wear face masks in stores, some require big-box chains, like Walmart, to close down their non-essential sections like furniture, home and garden, and arts and crafts.

Many companies and safety experts say it is not feasible to convert all grocery stores to delivery and pickup-only outposts.

Ordering for both pickup and delivery is completely overwhelmed by a crush of demand from customers in many areas of the country.

"We have no choice. They have to stay open. [America's grocery] delivery system has not matured to the point where we can switch to an entirely remote system," said Seth Harris, former deputy secretary of labor during the Obama administration.

Online pickup and delivery services require a large staff, much larger than grocery stores are currently equipped with. This could fill grocery stores to capacity with workers alone, which would defeat the purpose of removing the public from stores. In addition, having to pay more workers to manage pickup and delivery services would not be possible for many supermarkets.

They have already hired more workers during the pandemic to meet demand, and they're raising pay for existing employees to convince them to stay on the job. Grocers operate on razor-thin margins, and for many, the recent increase in sales because of coronavirus has been wiped out by the increases they've needed to make in payroll," CNN reports.

"I think that's one of the major reasons chains are reluctant to do the switch," said Logan from San Francisco State University.

A Trader Joe's representative said that while "we understand that during this time customers would appreciate a delivery or pick up service, the grocer's systems are not set up in a way that would allow us to be able to offer these services, and at the same time maintain our commitment to offering value to our customers."

Switching to online pickup and delivery is also a burden for customers who cannot afford fees that often come along with these services, customers without internet access, and food stamp recipients who are not able to use their assistance to purchase groceries online.