IAQ Services Inc.

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Millennium Office Building

Microsoft Corporation

William H Gates, CEO

6683 Columbus Business Pkwy  

Columbus, Ohio 45409

October 17, 2007

Re: Report on Office Indoor Air Quality Assessment: The Problem with Laser Printers

Dear Mr. Gates:

This is a report on the indoor air quality (IAQ) of the Millennium Office Building located at 6683 Columbus Business Pkwy, Columbus, Ohio 45409.

Summary

Air distribution was found to be insufficient and the HVAC system was unbalanced in several offices, especially the administration offices.  The air filter in the south end of the building was especially dirty.  It appeared to not have been changed as recently as the other air condition filters for reasons undetermined. 

There were numerous copiers and printers throughout the office building.  They were tested for particle emissions and four tested "very high" in fine particle emissions.  The mailroom copier was used for high volume printing (up to 10,000 copies per day) and is a high particulate emitter.

Cats are regular visitors to the back patio and other areas outside the building and may contribute to indoor cat allergen levels.  A number of recommendations are offered at the end of this report to address the issues noted.

Observations  See pictures.

Outside of Building	Main Corridor
South End of Offices	AC Filter near Administration
HP Color LaserJet 3550 Printer	Canon imageRUNNER 6020

Testing as a Means of Assessing Indoor Air Quality

There were a number of samples gathered in order to determine if there was contamination present in the offices.  The matrices tested were ambient air and air-condition filters.  Samples were gathered for total particulate, mold spores, common allergens, formaldehyde and volatile organic compounds (VOCs).

Airborne particulate sampling was done throughout the office building.  Particulate sampling was done in numerous areas of the office building with an airborne particle counter.^[1]

Results are shown in the following table:

The following is a graphical representation of the data above.  Note the contribution of four printers to the total airborne particulate.

A table summarizing other physical sample results follows:

Summary of Test Results at Office Millennium Building Alliance

September 15 and October 5, 2007

Discussion of Test Results

Results indicate that airborne particulate from certain printer/copiers is a contributor to poor indoor air quality.  The following room had problematic printers:

v     Small Kitchen-HP Color LaserJet 3550  (p)

v     Sales and Service-HP Laserjet 9050 (p)

v     Sales and Service-HP Color Laserjet (p)

v     Mail Room-Canon Image Runner 6020 at side vent (p)

These printers put out large bursts of ultra fine particulate matter (< 1 micron) in the ranges of 50,000 to 275,000 particles per cubic centimeter (about the size of a sugar cube) while printing was in progress.  Printer toner is being volatilized at high temperatures; and likely contains polyester resins, metallic compounds and amorphous silica.  The particle concentrations decreased rapidly when the printing ceased.  In the case of the mail room, particle counts remained high between printings.  Airborne paper particles may also be a factor here. 

The laboratory sample results were essentially normal except for cat allergen.  It was considered to be present in moderate concentration and likely airborne and inhalable at times since it was entrapped in the AC filter.  Cat allergen, a ubiquitous allergen from cat salivary glands (licking), was found to be present in the ambient office air.

Air circulation was found to be limited in several offices on the south end, especially Jenna and Mary's offices, as determined by carbon dioxide measurements.

Recommendations

1. Replace copiers that are noted to be high particulate emitters. 

2. Improve room ventilation in affected areas.  Improve air flow and rebalance the HVAC system to assure adequate flow of air to all areas of the building, especially the administration offices.  Consider increasing outside air contributions to the total air mix by resetting dampers on the HVAC units. 

3. Continue to use a high efficiency furnace filter, such as a 3M Filtrete Ultra or equivalent filter with a MERV rating of 10 or higher or install an electronic air cleaner on these units.

4. Routinely use a commercial hepa-vacuum[2] for all carpeting and upholstery in the offices within the building to remove settled particulate.  Thoroughly hepa-vacuum all carpeting and upholstery on the occupied floors of the office areas with a commercially available HEPA vacuum cleaner to remove settled particulate.  Wipe down hard, non-porous surfaces with a commercial cleaning product.

About IAQ Services Inc.

IAQ Services Inc. is a full service consulting firm in the areas of environmental health and safety testing and remediation.  Stuart Bagley is a consultant from IAQ Services Inc.  He is a Certified Industrial Hygienist (CIH) and a Certified Safety Professional (CSP).  He has a Master of Science degree in Occupational and Environmental Health from Wayne State University and a Bachelor of Science degree in Biology from the University of Michigan.  Mr. Bagley's field experience includes serving as a Compliance Safety and Health Officer for US Dept. of Labor-Occupational Safety and Health Admin (OSHA), working in corporate safety management, and as a senior consultant for IAQ Services, a total of 25 years.  He has conducted numerous indoor environmental quality investigations.

Thank you for assistance during this vital work.

Sincerely,

Stuart D Bagley

Stuart D. Bagley, MS, CIH, CSP

Attachments:  lab reports, pictures