Why Govt advised against using N-95 mask?

The central government has issued letters to all the state governments to not use N-95 masks. But the question is Why?Avoid wearing a mask which has valves or openings on the front as it might be a ‘one-way valve’ which is only going to protect the person wearing it. Maks with a one-way valve does not filter aerosols coming out of your mouth, hence, immediately putting those around you at risk.