BATH — More than 70 state lawmakers joined Maine delegates and union leaders in pleading for Bath Iron Works to do more to protect the health and safety of its 6,800 workers as statewide cases of coronavirus approach 700, but BIW held firm in its plan to stay open unless otherwise directed by the Department of Defense.

In a letter sent Monday to BIW President Dirk Lesko, legislators noted the Bath shipyard was designated as “essential” by Gov. Janet Mills and “critical infrastructure” by the Department of Homeland Security but wrote, “This designation allows, but does not require, a private business to stay open.”

BIW is a subsidiary of defense and aerospace company General Dynamics.

“DHS explicitly states that its designation of critical infrastructure is only ‘guidance,’ is ‘not binding,’ and ‘does not compel any prescriptive action’” legislators wrote. “Rather, it is a ‘decision support tool to assist state and local officials’ as they balance ‘public health concerns with infrastructure resilience.’”

Lawmakers also cited a letter then-acting Secretary of the Navy Thomas Modly sent to Rep. Chellie Pingree, dated April 7, in which he stated that “it is not appropriate for the Navy to direct how a contractor manages its workforce.”

Lesko responded Monday with a letter to the state legislators in which he wrote, “The Department of Defense is charged with responsibility for national security and it is up to the DoD to decide whether we remain in operation.”

Lesko said he received a letter from James Geurts, assistant secretary of the Navy, on March 19 that stated BIW is expected to continue operations during the COVID-19 pandemic.

“We have and will continue to provide our employees with choices to do what is best for their individual circumstances, while working to preserve the health and economic security of our workforce and communities by continuing operations in the safest manner possible,” wrote Lesko.

Legislators acknowledged steps the shipyard has taken to protect workers, such as requiring workers to wear face masks, suspending the use of private vans for commuting and sanitizing workspaces, but stated additional measures must be taken to protect public health.

“Individual employees report a close proximity of desks and other workspaces, not allowing for six-foot physical distancing,” legislators wrote. “Would BIW object to unannounced inspections of workspaces by state, local or federal health or safety officials to verify compliance with these or other health and safety imperatives?”

Maintaining a six-foot buffer between others has been repeatedly recommended by health officials, as coronavirus can spread from person to person through respiratory droplets in the air produced when an ill person coughs or sneezes.

Lesko wrote regulators are welcome to inspect BIW’s facilities, but the shipyard must be notified in advance and visitors will be required to undergo a security and health screening before entering because “national security protocols must be followed and during the time of pandemic we have severely restricted access to our facilities.”

Legislators also asked the company for details on what benefits are offered to employees who contract the virus, how many N95 face masks the company has, and what job security reassurance BIW has given to employees who choose to take the extended unpaid leave.

An N95 face mask is a respiratory protective device designed to filter airborne particles. The “N95” designation means that when subjected to careful testing, the respirator blocks at least 95% of small test particles, according to the FDA.

Lesko said the shipyard provides health insurance for workers and their families and offers employees “expanded eligibility and improved access for short-term disability benefits, company paid time for quarantine due to workplace direct contact with a COVID-19 confirmed positive individual, 100% coverage for COVID-19 testing and associated medical visits and waived all telehealth cost sharing to increase access for routine medical treatment.”

The company provided 3,200 N95 masks to Maine Health, but Lesko did not say how many masks the company has.

Legislators explained preventing an outbreak at the shipyard is imperative because, “We recall past episodes at BIW such as the tuberculosis outbreak in 1989-1990 or the 1918 flu fatalities in the BIW region, and hope to avoid a similar experience.”

After a tuberculosis outbreak at the shipyard infected over 570 workers in 1989, the Center for Disease Control conducted a study in which it noted, “Workers on the ships work in small, enclosed areas. … Conditions on the ships are frequently crowded; physical contact with people in some areas (passageways and cubbyholes) is almost impossible to avoid.”

These 72 lawmakers are not the first to demand answers and action from the shipyard.

Leaders of two of the shipyard’s largest unions, International Association of Machinists and Aerospace Workers locals S6 and S7, have called on the company to close and give employees paid leave repeatedly in the past several weeks as the virus continues to spread throughout the state.

The union’s calls for BIW to close were only renewed after BIW confirmed a second case of COVID-19 at the shipyard earlier this month.

Union leaders did not return requests for comment Monday, but Chris Weirs, president of Local S6, told television station WCSH6 last week, “I’d be shocked if there’s not a strike.”

Rob Hopper, a BIW employee for over six years, has both asthma and diabetes. He said he’s not concerned about getting sick. Instead, he took unpaid leave to protect his son, who has epilepsy, and doesn’t know when he’ll go back to work.

“I think BIW should close because it’s only a matter of time until they have a serious problem,” said Hopper. “I have friends who are still working, but they don’t want to, but they can’t afford (to take unpaid leave).”

David Arsenault, a BIW shipfitter of six months, hasn’t worked since Friday, March 13. He said he chose to stay home to keep both himself and his family safe and believes BIW should close for public safety.

“I think it’s in the state’s best interest to close because if it starts spreading in there, it’ll spread throughout the state,” said Arsenault. “Any county you go to, you’ll see someone wearing a BIW sweatshirt.”

As of Monday, Maine health officials reported 698 coronavirus cases in Maine, an increase of 65 cases from Sunday.