Would you expect a 6' tall man to wear the same size shoes as a 5'2" female? Probably not. The same applies to respirators. Each person's face is unique. For a respirator to protect, it must seal snuggly to the face at all sealing surfaces. This is why OSHA and the University require all respirator users to have a fit test.
Yes, if you are assigned to wear any tight fitting respirator, such as a disposable N95, half-mask or full-faced cartridge respirator. Even a day's stubble will compromise your protection by interfering with the mask to face seal. You can have a moustache and a tightly trimmed goatee that ends right at the chin line. Consider keeping shaving supplies at work if your need for a respirator is hard to predict from day to day. Loose-fitting hooded PAPRs (Powered Air Purifying Respirators) are the only approved respirator for bearded individuals. PAPRs cost much more than other respirators. Decisions are made at the department level as to whether budgets allow for PAPR purchase.
No. Unless you find a marking on the mask itself, or on the box that states "NIOSH certified N95 respirator," the mask is limited to protecting patients from your cough droplets, and protecting you from large droplet splashes, large dusts or your fingers from landing in your mouth or nose. These masks neither fit as well, nor filter as well as N95 respirators. N95s are designed to both fit better and effectively filter out tiny aerosol particles – such tuberculosis, mold or lab animal allergens. Please note that medical N95s also are approved for surgery. The N in N95 means the respirator is not resistant to oily particles such as mists from machine oils, oil-based spray paint, or pesticide spraying. For these oily aerosol hazards a R95 (Resistant to oil) or a P95 (oil Proof) respirator is needed – often in combination with an organic vapor cartridge. For more information please see the 3M Respirators and Surgical Mask Comparison (PDF format).