The answer to your question is; absolutely yes. Many particles, especially pathogens can be as small as .01 micron. The HEPA filters we use for the final stage of air filtration remove these smaller particles even more effectively than they do the 0.3 micron particles. However, most Industry standards require testing at 0.3 micron because it tends to be the Most Penetrating Particle Size (MPPS). In other words, particles between 0.2 and 0.3 are the most difficult size particles to capture and particle larger and smaller in size or more effectively captured. Therefore, if a filter is 99.995% efficient at capturing particles .3 micron in size, it will be more efficient at the .01 micron size. The reason for this is simply due to the fact that with these types of filters, there are multiple mechanisms associated with particle entrapment including electrostatic attraction, diffusion and Brownian motion. These 3 mechanisms are more effective in capturing the smaller particles than direct impaction from inertia. So, you can rest assured that your AIRBOX™ is working diligently and effectively at removing the full range of particles threatening the health of you and your family.