Fibre Glass Ducts, a Health Hazard?

August 1, 2000

To whom it may concern:

I would like to draw to your attention a serious flaw in the construction industry.

I don't know whether you are aware of it or not, but in the heating and air conditioning systems being installed, the contractors are using fibre glass ducts. It is much cheaper than the metal ducts which are usually wrapped on the outside with foil faced blanket fibre glass which is O.K. health wise. The fibre glass duct is light to handle, much faster to fabricate and much faster to install, and subsequently does not require insulating, being already made of fibre glass. The inside of the duct is raw fibre glass, the pressurized air passing through the duct keeps wearing off and blowing out into the air we (inhabitants of the building) breathe. I have talked to many sheet metal mechanics that have gone back on some of these buildings just a few short years after installation to replace some of this duct work, especially the 90 degree turns, to find only the foil paper left holding it together. Also, when they fabricate the various Y's and T's and various fittings, they install metal dampers so the air flow can be opened, shut off or diverted. When these dampers are operated they scrape the walls of the glass, so more loose fibers are released into the areas they serve.

This duct work is being installed every day, in every conceivable type of commercial buildings, e.g.; schools, office buildings hospitals, clinics ,etc.. One of the major manufacturers, Johns Manville (The Manville Corporation), has a warning label on every carton of fibre glass pipe insulation which is the same kind of glass duct is made of and states "Avoid breathing the fibre glass duct particles and wear protective clothing because this product has been found to cause cancer in laboratory animals". I am enclosing a copy of such a label from a typical carton.

I am not certain about this, but I have been told that the State of California has prohibited the use of fibre glass duct. I know that they require warning labels on fibre glass building products. I have also heard that Japan has considers the fibre glass particles as a real health hazard. Are we going to wait until the general public finds out about this health hazard as we did with asbestos ?

I do not know how many places are fabricating these duct systems but if you wish to see for yourselves first hand, go to the E.J. Bartells Co. at 2600 SE Mailwell, Milwaukie, Oregon (97222) and ask to see the fabrication shop. Have them demonstrate how the dampers work inside the duct. You will note that men doing the fabricating are all wearing masks. What protection does the unsuspecting public have ?

The sooner we stop this practice, the less we will have to remove later as with the legacy of asbestos insulation.

A concerned citizen and retired asbestos worker.

*** POSTED AUGUST 2, 2000 ***