HEPA filters are standard and remove 99.99% of particulate to 0.3 micron. In fabrication, dust happens. It's very small, floats everywhere, lands on everything in sight, and gets inside your tools. Due to its minute size, wood dust particles can be particularly troublesome to remove from an environment once airborne. The fine dust that is ejected into the air can make you sneeze, cough, and experience other allergy-like symptoms. Experts agree that limiting your exposure is the best protection.