Pressure on global supply lines in March meant PPE was being purchased quickly and often from different sources than those usually used in the health sector.
The ministry has reviewed all orders as part of routine due diligence to ensure quality and authenticity of PPE.
"DHBs that have received the masks of potential concern have been asked to put those items on hold while further quality checks are completed [as] a precautionary move. It does not mean that these items are non-compliant."
The masks will be restocked. The ministry's national store and DHBs have 50 million masks and 90 million are on order.