2. provide data indicating what types and sizes of particles are not removed by used PHEAF devices, and

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1 Comparison of In-Field Efficiency of 3 Different Types of Portable HEPA filter Equipment by Laser Particle Counter, Condensation Particle Counter and Light Microscopy Particle Counting. This study was conducted in April 2010 at OEHCS s facility in Las Vegas. The test chamber was specifically constructed to collect only the exhaust air from the PHEAF devices being evaluated. Study Hypotheses/Purposes This pilot study was designed and conducted to: 1. provide evidence that used PHEAF devices, as may be found in the field during use, do not remove percent of particles greater than 0.3 microns in size between the air at the PHEAF intake and the air at the PHEAF discharge, 2. provide data indicating what types and sizes of particles are not removed by used PHEAF devices, and 3. compare different particle measuring methods including laser particle counter, light microscopy particle counting, and ultrafine particle counting. 4. document that particles being discharge from PHEAF equipment that is not efficient can contaminate the discharge air spaces in this case the large test chamber. 5. validate that anisokinetics sampling was did not affect sampling results. 6. collect conclusive photographic evidence that carbon particles are not visible in light microscopy analysis air samples and are therefore too small to be of significance in infield testing of PHEAF equipment. 7. To test the effectiveness of HEPA filters for Nano Particle control using an Ultrafine Particle Counter. Study Participants Robert C. Brandys, president of OEHCS, Inc. Hinsdale, IL provided the test facilities, coordinated the experimental design, sampling and data analysis. Dale Walsh, MS, CIH, CSP, CEM (Walsh Certified Consultants, Inc Battle Born Drive, Las Vegas, NV assisted in the experimental design, sampling and data analysis. Daniel M. Baxter, president of Environmental Analysis Associates, Inc Soledad Road, San Diego, CA performed the analysis and photography of the particles on the filters.

2 PHEAF devices used were provided by a Las Vegas mold remediation and water response firm. The were used units ready to be used on mold remediation projects. Sampling Equipment 1. Particle Counter: 6 Channel Particle Counter ARTI Model s were taken for 21 seconds = 1 liter. This is 3 data sets that are averaged by the particle counter. Data sets are processed every 6 seconds by the particle counter. (See section on how laser particle counters work.) 2. Ultrafine Particle Counter: TSI P-Trak 3. Air Velocity: Alnor Junior 4. Air r: SKC Quick Take 15 Sampling Pump with Air-O-Cell inertial impaction aerosol sampling cassettes Test Specifics of the test chamber are shown in the diagram below. Three PHEAF devices were tested from 3 different manufacturers. These included a high volume air scrubber (rated at 1,000 cubic feet per minute [cfm]), a small air scrubber (rated at 500 cfm) and a HEPA back pack vacuum cleaner (rated at 75 cfm). Experiemental Sampling Protocol Data collected in the experiment included respirable particle concentrations between 0.3 and 10 microns in aerodynamic diameter, ultrafine (sub-micron) particulate concentrations, temperature, humidity, particulates collected on Air-O-Cell cassettes, and air velocity of the PHEAF exhaust (to calculate air changes) and of the general air present in the sampling chamber. Because of the size of the collection chamber air velocities

3 were approximately 100 fpm or less so no issues or questions about isokinetic sampling bias were present. Consequently, impacts from high air velocity on particle collection by the measuring devices were minimized. 1. The individual PHEAF device was installed and sealed to the test chamber. 2. The PHEAF device was turned on and operated long enough to produce a minimum of 10 air changes in the test chamber (less for the vacuum due to low air flow). Sampling was then initiated. 3. The air (outdoor air) near the intake of the HEPA device was measured for particle concentrations using the instruments described previously approximately three feet away from the intake and approximately four feet above the ground. 4. Laser particle concentrations were taken at the exhaust centerline discharge of the PHEAF equipment approximately one foot away from the exhaust opening in the test chamber. 5. Laser particle concentrations were measured next to the SKC Quick Take 15 Sampling Pump approximately four feet above the ground inside the test chamber. 6. Laser particle concentrations were also measured at the exit air slit to document consistent particle concentrations throughout the test chamber. 7. Particle concentrations and types were also measured using the Air-O-Cell cassette in the middle of the test chamber. 8. A second duplicate set of samples were collected for each device on the intake and exhaust for all 3 pieces of PHEAF equipment immediately after the first set was completed. Results were averaged were appropriate. 9. The Air-O-Cell samples were carefully packaged and sent to Environmental Analysis Associates, Inc. using Chain-of-Custody procedures for analysis and microphotograph. Analysis by Environmental Analysis Associates, Inc. s were microscopically analyzed for : 1. Opaque particle counts and Total particles > 3 microns. 2. Mold and pollen 3. Photographs of the particles on the filters were taken for visual comparison of intake and exhaust particle types and sizes. Calibration Calibration certificates for the particle counters were provided by the equipment rental company. Particle Data Results From the Study

4 The tables below compare the laser particle counting results with the light microscopy particle counting results. Ultrafine particle counts, because they are an integrated counting result for particle between 0.02 and 1.0 micron are analyzed and compared individually after the microscopic and laser particle data. The test results are arranged in the order the testing was done. 1. Large size HEPA air scrubber (1500 cfm), backpack HEPA vacuum (100 cfm) and mini size HEPA air scrubber (500 cfm), Test 1. Large Portable HEPA Air Scrubber Used Laser Particle Counter and Microscopic Particle Analysis Data Showing Removal Efficiency Background Particle Levels (p/ft3) Particle Levels (p/ft3) Test Start At HEPA By 1 in test By 2 in test from Test Efficiency (p/ft3) Removal Efficiency % % % % % % Microscopic Analysis vs. Particle Levels Particle Type Units Removal Efficiency

5 Mold Pollen Opaques Total Particles >3 microns s/m3 p/m3 p/m3 p/m , ,766 67, ,720 96, , ND ,714 13, , ,286 77% 96% 92% 89% Testing Conclusion: This was a PHEAF device that was acceptable for most applications based on the laser particle counter results. The microscopic analysis showed slightly less efficient particle removal. Microphotographs The first two pictures below show the microscopic particles in the background air entering the intake of the large HEPA air scrubber. The next two pictures show the discharged microscopic particles from the exhaust of the large HEPA air scrubber. Some smaller particles are still present in the exhaust as reflected in the particle count and microscopic analysis data. INTAKE SAMPLE 1 LARGE HEPA AIR SCUBBER

6 INTAKE SAMPLE 2 LARGE HEPA AIR SCUBBER EXHAUST SAMPLE 1 LARGE HEPA AIR SCRUBBER SCUSCUBBER

7 EXHAUST SAMPLE 2 LARGE HEPA AIR SCUBBER Test 2. HEPA BackPack Vacuum Used Laser Particle Counter and Microscopic Particle Analysis Data Showing Removal Efficiency Background Particle Levels (p/ft3) Particle Levels (p/ft3) Test Start At HEPA By 1 in Test By 2 in Test Slit from Test Slit from Test Chambe

8 Efficiency (p/ft3) Removal Efficiency % % % % % % Microscopic Analysis vs. Particle Levels Used HEPA Vacuum Particle Type Units Removal Efficiency Mold s/m , % Pollen p/m ND 17 88% Opaques p/m 3 25,371 29,486 27,429 15,771 13,371 14,571 47% Total Particles > 3 microns p/m 3 165, , ,560 57,600 59,520 58,560 74% Testing Conclusion: This was a PHEAF device that was a particle pump for respirable particles. It was actually adding more small particles than it was removing. However, it did have some effectiveness for the larger pollen and mold spores as indicated in the microphotographs. This, of course, questions whether this vacuum actually contained a true HEPA filter or just a high efficiency filter. (The HEPA filter was in the vacuum.) The microscopic analysis showed similar removal efficiency for the larger size particles. However, since microscopic analysis is limited to larger particles it did not detect the large numbers of respirable particles being released by this device. Microphotographs The first two pictures below show the microscopic particles in the background air entering the intake of the large HEPA air scrubber. The next two pictures show the discharged microscopic particles from the exhaust of the large HEPA air scrubber. Some smaller particles are still present in the exhaust as reflected in the particle count and microscopic analysis data.

9 INTAKE SAMPLE 1 HEPA VACUUM USED INTAKE SAMPLE 2 HEPA VACUUM USED

10 EXHAUST SAMPLE 1 HEPA VACUUM USED EXHAUST SAMPLE 2 HEPA VACUUM USED

11 Test 3. Small HEPA Air Scrubber Used Laser Particle Counter and Microscopic Particle Analysis Data Showing Removal Efficiency This was the most interesting test of the 3 HEPA devices. This test showed one of the more interesting properties of some HEPA filters. In this case, the longer the filter operated, the more efficient it appeared to become. This increase in efficiency is reflective of a build up of a static electrical charge (due to air flow friction) that makes the HEPA filter more efficient especially for smaller particles. This was also reflected in the high ultrafine particle efficiency of this filter media. Background Particle Levels p/ft Particle Levels p/ft3 At HEPA By r in Test By r in Test From Test From Test Efficiency p/ft3 Start Removal Efficiency* End Removal Efficiency** Avg. Removal Efficiency , , , *Efficiency At HEPA / Background **Efficiency At last silt exhaust from test chamber/average background Microscopic Analysis vs. Particle Levels Mini HEPA Particle Type Units Removal Efficiency

12 Mold s/m % Pollen p/m % Opaques p/m 3 8,194 41,829 25,012 4,834 3,600 4,217 47% Total Particles > 3 microns p/m 3 136, , ,880 42,240 19,200 30,720 84% Testing Conclusion: Testing Conclusion: This was a PHEAF device that appeared to become more efficient the longer it was operated. This was a PHEAF device that was acceptable for most applications based on the laser particle counter results. The microscopic analysis showed slightly less efficient particle removal. Microphotographs The first two pictures below show the microscopic particles in the background air entering the intake of the large HEPA air scrubber. The next two pictures show the discharged microscopic particles from the exhaust of the large HEPA air scrubber. Some smaller particles are still present in the exhaust as reflected in the particle count and microscopic analysis data. INTAKE SAMPLE 1 MINI HEPA AIR SCRUBBER 10 µ

13 INTAKE SAMPLE 2 MINI HEPA AIR SCRUBBER 10 µ EXHAUST SAMPLE 1 MINI HEPA AIR SCRUBBER 10 µ

14 EXHAUST SAMPLE 2 MINI HEPA AIR Analysis of Laser Particle Count Data As shown in the tables above as well as the summary data of PHEAF equipment testing in Chapter. PHEAF equipment does not test with a laser particle counter to 99.97% effectiveness at 0.3 microns. Further, some PHEAF equipment can actually function as particle pumps releasing more small particles into the discharge air stream than are entering the equipment. The source of these particles was not investigated but likely sources are small particle collected from previous activities that are shed as the filter degrades during use. They could also be from degradation of the filter media itself. The microphotographs, because they were of particle larger than 3.0 microns provide no information on the source of these particles. The graph below compares the laser particle data to the microscopic data using the assumption of a log normal distribution with a slope established by the shown equations. All data has be adjusted to particles per cubic meter. As one can see, the microscopic particle counts appear to be higher than the laser particle counts. This is probably due to particle >10 microns being counted by light microscopy. As similar difference between background air and discharge in not shown in graph 3 of the backpack HEPA device. This is because the backpack HEPA vacuum was a particle pump.

15 Conclusions based on Laser Particle Count and Microscopic Analysis Data 1. No PHEAF device tested HEPA efficient by any of the particle counting methods.

16 2. Microscopic particle counts were significantly higher than laser particle counts. This may have been due to the fact that the laser particle counter does not count particle greater than the 10 micron cut off diameter. Particles larger than this size would have been counted in the light microscopy analysis. 3. Particle Removal Efficiency Rating of individual PHEAF devices were lower for the light microscopy particle counts that the calculated laser particle count efficiencies. 4. The relationship between µ particles measured by a laser particle counter and the concentration of µ particles measured by a condensation particle counter can possibly be compared assuming a log normal distribution of airborne particles. UltraFine Particulates Ultrafine particle counts, because they are an integrated counting result for particle between 0.02 and 1.0 micron are analyzed and compared individually below. Test 1. Large Portable HEPA Air Scrubber Used Laser Particle Counter and Microscopic Particle Analysis Data Showing Removal Efficiency Background Particle Levels p/cm ,000 15,000 10,500 14,000 13,000 Particle Levels p/cm3 At HEPA By r in Test By r in Test From Test From Test Efficiency p/cm3 Removal Efficiency , % Test 2. HEPA BackPack Vacuum Used Laser Particle Counter and Microscopic Particle Analysis Data Showing Removal Efficiency Background Particle Levels p/cm ,000 15,000 13,000 13,500 13,000 13,700 Particle Levels p/cm3 At HEPA By r in Test By r in

17 Test From Test From Test ,000 13,000 13,500 12,500 12,500 10,625 Efficiency p/cm3 Removal Efficiency ,700 10, % Test 3. Small HEPA Air Scrubber Used Laser Particle Counter and Microscopic Particle Analysis Data Showing Removal Efficiency Background Particle Levels p/cm ,000 14,000 14,000 15,000 15,000 14,400 Particle Levels p/cm3 At HEPA By r in Test By r in Test From Test From Test Efficiency p/cm3 Removal Efficiency , % Data Analysis As one can see in the ultrafine data tables above each of the different PHEAF devices had significantly differing ultrafine collection efficiencies. Conclusions 1. The data shows that ultrafine particulate collection efficiency cannot be determined by micron laser particle counter. 2. Ultrafine collection efficiency can be measured using a condensation particle counter. 3. HEPA filters cannot be assumed to also be effective in controlling ultrafine particles.