its always better to be safe than sorry but you should be just fine as long as you wasn't going ape shit sharpening it. Others have said they've seen no SDS stating to wear a respirator but you wont find a SDS on silicon carbide products 90% the time and that will cause silicosis which is a basically a brutal form of COPD because the more silicon carbide in your lungs the more those fine particles will destroy your air passages to absorb oxygen.