Yet Covid patients continued to be scattered through the Oakland hospital, according to complaints to California’s division of occupational safety and health (Cal/Osha).

They include a claim that a Michigan hospital kept patients who tested negative for the virus in the Covid unit in May.

An upstate New York hospital also kept Covid patients in the same unit as those with no infection, according to a closed complaint to the federal Occupational Safety and Health Administration.

At Alta Bates in Oakland, hospital staff made it clear in official complaints to Cal/Osha that they wanted administrators to follow the state’s unique law on aerosol-transmitted diseases.

From 10 March through 30 July, Hill’s union and others filed eight complaints to Cal/Osha, including allegations that the hospital failed to follow isolation rules for Covid patients, with some being placed on the cancer floor.

The string of complaints also say the hospital did not give staff members who cared for virus patients the personal protective equipment (PPE) required by state law – an N95 respirator or something more protective.

Instead, Hill said, staff on floors with Covid patients were provided lower-quality surgical masks, a concern reflected in complaints filed with Cal/Osha.

A Sutter Health spokesperson said the hospital took allegations, including Cal/Osha complaints, seriously and its highest priority was keeping patients and staff safe.

The statement also said that “cohorting”, or the practice of grouping virus patients together is a tool that “must be considered in a greater context, including patient acuity, hospital census and other environmental factors”.

A recent study reported “extensive” viral contamination around patients with Covid-19 there, but noted that with “standard” infection-control techniques in place, staff who cared for infected patients did not get the virus.

Barbara Lewis, southern California hospital division director with the union, said Covid patients were kept on the same floor as cancer patients and post-surgical patients who were walking the halls to speed their recovery.

A hospital spokeswoman, Jessica Chen, said the hospital “quickly implemented” changes directed by state health authorities and does place some Covid patients on the same nursing unit as non-Covid patients during surges