With four days remaining until Gov. Charlie Baker is due to put details on his economic reopening plan, the business community is growing more antsy about how it will all work.

“The state will have a four-phase reopening, however, there are still no clear triggers for each phase, including phase one,” the Greater Boston Chamber of Commerce wrote Wednesday in an update to its previous policy brief which had urged Baker to sketch out public details to ensure businesses have time to plan.

In the update, the chamber described protecting the public health as “the primary concern” but said that when the governor announces his plans on Monday, businesses will be looking for specific information on reopening phases, metrics and triggers and a statewide goal on testing.

The chamber said some employers will want to conduct testing for employees, but said employer-based testing needs to be part of a broader state effort to provide widespread access to affordable testing for all.

“Relying only on employers to coordinate a response may result in haphazard testing for enormous swaths of the population including retired people, students, and those who became unemployed as a result of the economic shutdown,” the chamber said. “The state should also oversee communicating how, where, and when to get tests; detail the statewide capacity to manufacture, administer, and analyze tests; and remove legal or regulatory barriers to ramping up testing capacity.”

Chamber officials are also looking to Baker for information about how Massachusetts will use $45 million in Child Care and Development Block Grant funding from the federal CARES Act, clear guidance to address liability concerns among employers, and, for workers who must use the T to get to their jobs, a “robust communications plan” covering how and when service MBTA will run.

Baker, however, rejected the chamber’s calls Wednesday afternoon and pushed back against critics who have accused him of moving too slowly to restart the state’s economy as he simultaneously tries to steer the state through the COVID-19 crisis.

“I would love to be able to open everything up tomorrow. That would be an incredibly irresponsible thing to do,” Baker said.

Baker addressed questions about his phased-in reopening plan from the parking lot of a community health center in Fall River where he traveled to tour one of the state’s drive-through testing sites. The Stanley Street Treatment and Resources Center was one of the 18 community health centers that the administration teamed with Quest Diagnostics to provide supplies and support for testing.

Baker said residents have sacrificed too much over the past nine weeks to risk a second breakout of the virus because of growing impatience. His message of caution has been reinforced in recent days by officials like Attorney General Maura Healey, who said on the radio Tuesday that a “true patriot” would follow the governor’s instructions.

“People have gone through a tremendous amount of dislocation and discomfort and lost wages and a whole bunch of other things over the course of the past 60 days to get to get to the point where the virus has been contained enough and reduced enough that we can actually start to reopen the economy,” Baker said. “The last thing we’re going to do is reopen it in a way that fires that virus up again.”