Patching
Asbestos in Patching and Other Building Materials
The term "patching" usually refers to "patching plaster", a substance that has historically been used to plug holes, cracks, gaps and other types of blemishes and damage in building walls and ceilings. Plaster itself is a dry-mix compound made from gypsum, lime, cement and various types of fiber – including asbestos fibers. When water is added to patching plaster, it forms a substance that is similar in texture and consistency to mud and can be spread, molded and applied to other surfaces. Eventually, it dries and forms a hard surface.
In patching plaster, two types of asbestos were generally found. The most common type of asbestos used commercially was chrysotile. This was the most likely asbestos ingredient in patching plaster, and accounted for about 95-98% of all commercial asbestos. Another type of asbestos commonly found in patching plaster is tremolite. While never commercially mined, processed or sold, tremolite was a contaminant in another substance known as vermiculite. The latter was mined near asbestos sources, and was used not only as an ingredient in patching plaster, but insulation and even gardening products as well.
Patching Products Containing Asbestos
The following partial list of patching products were known to contain asbestos:
| Product Name | Start Year | End Year |
|---|---|---|
| Bondex Handy Patch All Purpose Patcher | ||
| Bondex Multi-Patch | ||
| Bondex Reardon’s Handy Patch All Purpose Patcher | ||
| NARCO BOF-Patch | ||
| Synkoloid Flexi-Patch | ||
| Synkoloid Stucco N Cement Patch | 1950 | 1975 |
| Synkoloid Synko Patch-All | ||
| Synkoloid Vinyl Concrete & Masonry Patch | ||
| United States Mineral Cafco Patching Fiber |
Hazards Associated with Patching Products
Builders, repairmen, and building maintenance workers are the people most likely to have been exposed to asbestos as a result of contact with patching plaster. The dry plaster material was the most dangerous in terms of asbestos exposure, as it contained raw asbestos fibers that could very easily be inhaled. Patching plaster, once applied, is relatively safe unless the material begins to peel or crack, again allowing individual fibers to escape. Inhalation of asbestos fibers is strongly linked to the development of lung cancer, asbestosis, and malignant mesothelioma.
Sources
Bowker, Michael. Fatal Deception: The Untold Story of Asbestos (New York: Touchstone, 2003)
