"Many countries returned consignments of PPE on the basis of poor quality. SA did not have widely known cases where it returned consignments for poor quality," said Delihlazo.
It was not immediately clear if the national health department would recall the masks.
Approached for comment, department spokesperson Popo Maja asked for the study outcomes to be shared with them. There was no response by the time of publishing.
"In the meantime, Denosa urges all its shop stewards in facilities across the country to up their defence guard and demand proof of safety if nurses working in high-risk areas like Covid-19 units are given the KN95 masks," said Delihlazo.
The study has recommended against the use of the KN95 masks, and said as piles of boxes of these masks remain in institutions, the masks could be moved to other highly infectious and risky areas like TB units.
"Denosa does not trust that government will not move these masks elsewhere once the Covid-19 pandemic has passed," he said.
Delihlazo said the department needed to beef up the number of health workers in facilities to deal with the second wave of the pandemic.