Here is a link to a well-informed site :
ECDC risk assessments aim at supporting the EU/EEA countries and the European Commission in their preparedness and response to a public health threat.
www.ecdc.europa.eu
If the face-mask has not specifically been made for use in infectious situations (we talk about a virus here, not bacteria), they are useless.
And indeed, as for now, infection is transmitted by droplets (coughing, sneezing, ...) and via the faecal-oral route.
So the old hygienic measures : do not spit, cough behind your hand, sneeze in your handkerchief, WASH your hands after using toilet or public transportation, before eating, wash fruit and vegetables, ... still are valid.
DO NOT PANIC !