The Washington state Department of Health will no longer recommend health care workers wear air-filtration masks when caring for patients diagnosed with COVID-19.

The change is a departure from guidelines issued by the Centers for Disease Control and Prevention on personal protective equipment for health care providers treating people with COVID-19. Instead, the state DOH is opting for the World Health Organization’s guidelines.

The largest difference between the two sets of guidelines lies in the type of mask a health care provider wears when treating a patient with COVID-19.

Current CDC guidelines require N95 protective masks or respirators for health care workers treating patients with COVID-19, which filter at least 95% of airborne particles. N95 masks block airborne and droplet transmission and fit much tighter around the face.

Current WHO guidelines require normal or surgical facemasks, which protect against droplet transmission, from sneezing or coughing, but do not form a seal around a person’s face, Food and Drug Administration guidance shows.

A letter from Sara Podczervinski, who manages the state DOH infection resistance program, to health care partners lists the gear now necessary for health care workers.

The WHO’s guidelines include a facemask, gown, gloves and eye protection. N95 respirators are required for aerosol-generating procedures.

“This departure from CDC will allow Washington State healthcare providers to maintain consistent infection transmission precautions across multiple care settings,” Podczervinski wrote.

The DOH did not respond to requests for comment about why they have made this decision by press time. On Friday a coalition of unions that represent health care workers released a statement calling on the CDC to keep its personal protective equipment guidelines.

In her statement, Sally Watkins, executive director of the Washington State Nurses Association, said that N95 respirators are the necessary, minimum protection for nurses and health care workers.

“In Washington state, we have heard from nurses that they don’t feel they have the personal protective equipment (PPE) they need, are not getting adequate real-time training, and don’t feel prepared,” Watkins said in the news release. “Lowering the standards for protective gear will weaken the ability of nurses and other frontline caregivers to safely care for their patients in this public health emergency. N95 respirators are the necessary and minimum protection for our nurses and healthcare workers.”

Watkins called on the federal government to increase the national supply of N95 respirators and other PPE.

“The federal government should do all in its power to increase the supply of N95 respirators and other PPE, which includes releasing the national stockpile and targeting supplies to areas where the outbreak has already occurred; incentivizing U.S.-based companies to produce more N95s; and promoting the use of powered air-purifying respirators (PAPRs) in healthcare settings,” her statement continued. “Healthcare professionals also need training in real time on how to properly use the respirators, with opportunities to practice and to ask questions.”

WHO guidance on personal protective equipment says that the COVID-19 virus is transmitted between people through close contact and droplets, not by airborne transmission, acknowledging that those who care for COVID-19 patients are most at risk of infection. Additionally, the WHO guidance on PPE says the global supply is low.

“The current global stockpile of PPE is insufficient, particularly for medical masks and respirators; the supply of gowns and goggles is soon expected to be insufficient also,” interim guidance from WHO says.

Some nurses and health care workers are concerned about the state health department’s switch to WHO guidelines because they view the CDC as the gold standard.

“My main concern is that we’ve always used the CDC as our gold standard, and now the Washington Department of Health has decided to go against what we’ve always considered to be the gold standard in this country,” Clint Wallace, a local intensive care unit nurse, said. “That’s putting a lot of nurses and health care workers on edge.”

Wallace said he would not have been concerned with the state’s move to WHO guidelines if the CDC had issued such guidance first.

“If the CDC were to make this change I think everybody would know they have the evidence-based information to make that change, but they have not made that change,” Wallace said.

The CDC was still recommending airborne precautions at press time.