Workers affiliated to National Education, Health and Allied Workers' Union (NEHAWU) staged the protest outside the NHLS headquarters, blocking entrance to the building.
The National Health Department released figures on August 4 reporting that 240 health workers had died from COVID-19 - 203 of which worked in the public sector - and over 27,000 infected.
"We are in a war with the employer. And a war has got a tendency of having fatalities. And it's unfortunate that when those fatalities are happening, it is our own people who are affected," said Juda Mpathi, NEHAWU Branch Secretary.
The NHLS is the largest diagnostic pathology service in South Africa responsible for supporting the national and provincial health departments in the delivery of healthcare.
Health Minister Zwelini Mkhize said in a statement on Monday, "I have recently had serious engagements with a number of trade unions and I have said if there is any health worker that raises matters of safety, it must be taken seriously."
He added, "We have adopted the slogan: NO PPE, NO WORK."
South Africa has reported 611,450 confirmed cases of the virus, and 13,159 deaths.
