MONTREAL -- Daycare services in Quebec have been using the wrong masks for months.

Families Minister Mathieu Lacombe sent a notice to daycare services on Tuesday asking them to immediately stop using MC9501 masks distributed to many of the province's 15,000 daycare centres. 

They're being recalled because they do not meet safety requirements, according to the Robert-Sauvé, from the research institute in occupational health and safety. 

The filtration of the mask is what's problematic; it doesn't always work.

These masks were distributed in daycare centres between May and November. 

The ministry says it received the information from the CNESST on Tuesday, the same day it informed the daycare services.

"As soon as we learned about it, we acted immediately. The health and safety of the members of the staff of the network is really our priority," Lacombe said in an interview on Wednesday.

By a "combination of circumstances" the ministry had already ordered other masks that do fit the guidelines. 

"We were working with the stock of masks that we had since the start of the pandemic, it was known that this stock was coming to an end. We had to order new ones," Lacombe said. 

The new masks are already at daycare centres or will be in the coming days, he added. 

Lacombe also said the situation in childcare settings is "exceptional" since there have been only 951 cases associated with the centres since the pandemic began. 

"Things are going well in our educational childcare services," he said. "When we look at the results, we see that the protective measures are effective even if in this case we are told by the CNESST that a more efficient mask should be used." 

This report by The Canadian Press was first published in Dec. 23, 2020. With files from CTV's Kelly Greig.