Ask the Expert Question-and-Answer Archive

by Ron Joseph

August, 2009

319 compliant- Filter Efficiency vs 3 Physical Stages

Q. Have you heard of any legislation that has shown that two or three stages are not necessary as long as the final stage has been certified to comply with the minimum efficiency levels found in Method 319.

If a booth operator does not install the sacrificial layer of a filter system it seems like it should not be a problem because the final filter meets the method 319 so the other two stages are just to save money and save having to replace the final filter as pressure drops get out of range.

A. I believe you are correct. If the regulation requires you to have a two-stage filter but you would prefer to have only a single stage, you must meet the capture efficiency requirements of the second stage. Similarly, if you are subject to a regulatory requirement of a three-stage filters system your final filter must pass the third stage capture requirements of EPA Method 319. You do not need to have prefilters if prefer not to.

Regards,

Ron Joseph