Feel free to talk to us! Phone Number: 973-366-4660

Black Streaks in my Office: Mold or What?

If you need mold sampling/testing assistance as discussed in this article call us at 973-366-4660 or email us at info@atlenv.com for details and a free estimate.

Written by Robert E. Sheriff, MS, CIH, CSP, President and Henry P. Shotwell, Ph.D., CIH, Vice President

February 4, 2020

Black Streaks in my Office: Mold or What?

I see black streaks radiating out from ceiling diffusers. The question asked is “Is this Black Mold?” Rarely is it Black Mold, but it’s not impossible. Black Mold usually grows on damp paper such as the paper surface of sheetrock. It can grow outdoors on decomposed wood and be brought into the HVAC system. More often than not though, that black stuff is soot. In many cases, it is carbon from vehicle tires especially in metropolitan areas or where there is a large amount of vehicle traffic. It can also be carbon emissions from vehicles and stationary sources.

Soot is formed from the incomplete combustion of carbon-containing fuels. Although natural gas, wood fires, candles, and home heating oil are typical sources, soot can be formed during any combustion process. A recent research project which looked into this Black Soot Deposition (BSD) phenomenon revealed that candles are a common (but not the only) source of BSD. Soot can also be from diesel (truck) engines. Thus, in cities and towns, the diesel soot is likely to appear on the diffuser bringing outside air into the office. Soot can also come from cigarettes, pipes, and cigars. Also, soot can come from boilers, lift trucks, lubricating oils, welding, and any other combustion.

Soot particles are extremely small, usually less than a micron in diameter (a micron is 4.4 millionths of an inch). They are so small that they easily pass through air-conditioning filters but are too small to be seen until they accumulate. Soot particles tend to deposit on cool surfaces such as walls, floor carpeting, and air supply vents, which are precisely where they are seen. They also deposit on electronically charged surfaces like computer screens and plastic Venetian blind slats. Also, because soot particles are so small, they can penetrate to the alveoli, the deepest parts of the lungs, where gas exchange occurs.

If a soot problem exists, testing/sampling the office air quality and inspection of the HVAC system by an Indoor Air Quality Expert is the proper first step. Laboratory analysis by optical microscope or the more precise SEM (Scanning Electron Microscope) is necessary to define what the black particles are—mold or soot.

Having the Heating, Ventilating, Air Conditioning (HVAC) system inspected regularly, filters changed regularly, and the entire HVAC system cleaned is recommended.

For more information contact Atlantic Environmental.

Our primary service areas are NJNYNYCPACTDE(Boston) MARIWash DCWIMDMI(Chicago) ILVAIN(Atlanta) GAALNCSCTN(Dallas, Ft Worth) TXOKDCAR. We can service most other areas of the U.S. but with some added travel charges.

This entry was posted in Indoor Air Quality (IAQ) News & Technical articles, Uncategorized and tagged . Bookmark the permalink.