Lt. Gov Karyn Polito addresses reporters at an April 22 press conference. State House News Service Photo / File

The first wave of businesses shuttered by the COVID-19 pandemic could begin to reopen around May 18 if public health data continues to trend in a positive direction, Gov. Charlie Baker said Monday as his administration unveiled a four-step plan to move from widespread shutdowns into a “new normal.”

One week before a panel tasked with laying out reopening strategies publishes its report, Baker and Lt. Gov. Karyn Polito offered an outline of how the process will unfold. It will start with industries that are best able to limit face-to-face interaction and transmission risks for the highly infectious virus.

All businesses will face a range of new mandatory safety standards once they resume operations, and state officials will also lay out industry-specific requirements.

All employers in Massachusetts will be required to follow a set of safety standards unveiled Monday. Officials hope the stricter requirements – which cover hygiene, cleaning, social distancing and business operations – will lower the risk of coronavirus spread and stave off a potential second surge in cases. Industry-specific safety standards will be released in the coming days, Polito said.

To comply with the standards, every business must ensure customers, employees and vendors are at least 6 feet apart “to the greatest extent possible.” Employees must wear face coverings or masks and wash their hands frequently, and employers have to ensure disinfection of all shared or frequently touched surfaces “at intervals appropriate to said workplace.”

Any workers who display COVID-19-like symptoms should not report to work, the regulations order, and if any employee is diagnosed with the illness, the employer must conduct a round of cleaning and disinfecting.

That first phase, which the administration titled “Start,” could begin as soon as next week. Phases two, three and four – dubbed “Cautious,” “Vigilant” and “New Normal,” respectively – will follow. The timeline for those phases will depend on how well the state is able to contain COVID-19.

“The goal is to begin this process around May 18, but it will be gradual and facts on the grounds will determine if we actually hit that goal,” Baker said.

During a question-and-answer period with reporters, Baker noted that other states are pacing phases one month apart unless COVID-19 case data indicates changes should be made. Signage, public education campaigns and social pressure will be a critical component of enforcing safety regulations in public spaces, he said.

“I’m confident Massachusetts residents will stand up and accept their responsibility,” Baker said.

Updated: 8:12 a.m., May 12, 2020: This story has been updated to include information about standards all businesses must follow, and a link to a Baker administration presentation offering more detail.