President Donald Trump’s executive order reopening meatpacking plants shuttered because of COVID-19 is already drawing scrutiny from an array of labor and civil liberties unions, concerned that his declaration may also be used to circumvent legal protections for workers and the public.

But even that 1950-era legislation known as the Defense Production Act, which gives the president sweeping powers to requisition property, override state and federal regulation and offers some limited immunity for civil claims against company’s ordered into service, doesn’t shield employers from liability for knowingly putting workers at risk of physical harm.