The blue and red logo must be on every cloth mask available to the public from May 11 and is aimed at limiting fraud.The logo shows the capacity of filtration of the mask with the words “filtration garantie.” 

It also shows how many times the mask can be washed with four variations: "testé 5 lavages" (tested for 5 washes), "testé 10 lavages" (tested for 10 washes), "testé 20 lavages" (tested for 20 washes) and "testé 30 lavages" (tested for 30 washes).

A mask that is washable five times can be used six times, and a mask washable 10 times can be used 11 times etc, the Ministry of Economy has said.

The wording "filtration guaranteed" certifies that the mask has passed a test carried out by the French Defence Procurement Agency (DGA). It means that the masks filter particles emitted (of a size equal to or greater than three microns) ranging from at least 70% to more than 90%, said the Economy Ministry in an official statement.

These masks, unlike surgical or FFP2 masks for example, only stop particles from the wearer. Thus, contamination can only be avoided if everyone wears them.

It is stressed that barrier gestures must still strictly be respected when wearing a mask.

Read more: Pharmacies in France will now sell face masks