One of the workers said he had worked at QSi for several years and said he felt it was cold and ruthless the way they had been let go.
"A lot of people have got a lot of resentment here," the worker, who did not want to be named, said.
QSi has been approached several times for comment, but has not responded.
The company manufactures and distributes safety and medical products out of its Pacific Place site.
Staff were told company directors had discussed and agreed upon which parts of the business were "core" and which parts were "non-core".
As well as the masks and respiratory part of the business there were also height safety, signs, first aid and medical, spill and absorbency, sewing and safety products.
The assets in the height safety part of the business would be sold and a "tentative agreement" had been reached with another company, Amtech Medical, to take it over from June.
Amtech Medical is a medical supplies company with its head office in Heads Rd in Whanganui.
Jeremy and Craig Anderson are both listed as major shareholders of Amtech Medical Ltd.
The staff being let go were told two part-time jobs at Amtech were available if they wanted to apply.
The spill and absorbency as well as first aid and medical parts of QSi are also under "tentative agreement" to go to Amtech.
QSi will shut down its signs, sewing and safety products parts of the business and all of them would have staff reductions.
The worker said management asked the staff being made redundant to give them their CVs and they would ask other businesses if they needed staff.
But the worker said that had not led to anything.
"They just tell us what we want to hear and then nothing."
In April 2020, QSi cranked up its production of face masks as the Covid-19 pandemic took hold in New Zealand and the Government had put everyone under lockdown.
In August that year, Prime Minister Jacinda Ardern visited the factory to see the mask production in action.
