During the purchase or renovation of a property built before the 1980s, many homeowners will question if asbestos-containing materials are present. When inspecting a property, many people ask what were the peak years for asbestos to be used in homes. Overall modern asbestos production started in the 1800s during the industrial revolution and dropped off in the late 1970s after regulation banned certain asbestos products and uses. According to the USGS the United States was the leading country in asbestos usage until the 1960s, when it was surpassed by the Soviet Union. While there are a plethora of asbestos-containing materials, in this blog we will discuss the years of use for pipe insulation, vermiculite, and wall systems.
Asbestos insulation was used widely in homes and typically associated with piping and ductwork. One of the more common insulation products is known as AirCell, a thermal system insulation (TSI). Air-Cell pipe insulation was created by the John Manville Corporation in 1908 and discontinued between 1915-1920. In a 1990 study conducted by the EPA, they found that out among various building types, buildings built before 1944, apartment buildings, and buildings with 8 floors or more are most likely to contain some form of TSI. Even though Air Cell was discontinued in the early 20th century, John Manville produced other similar pipe insulations such as Asbestocel until the 1970s.
Vermiculite refers to a mineral that is coveted for its insulating properties and commonly used as attic insulation. Its appearance is a gold to brown pebble material that shimmers in the light. The mineral was usually mined in Libby Montana, which was contaminated with the regulated asbestos mineral Tremolite, and the unregulated Libby amphibole minerals. One common commercialized product of vermiculite is known as Zonalite. According to the EPA, between 1919 to 1990 over 70% of the Vermiculite sold in the United States originated from Libby Montana. The EPA recommends if Vermiculite is observed in a home to assume it is asbestos-containing.
Asbestos-Containing Wall Systems
Some common wall systems where asbestos is present are plaster and drywall. Plaster walls are usually made of a mix of sand, lime, and cement mixture. It can appear in various textures, such as popcorn, stucco, acoustical, and decorative designs. Asbestos-containing plaster was produced by United States, National Gypsum Gold Bond, Georgia-Pacific, and other manufacturing corporations primarily between 1920-1976.
Asbestos can be found not only in drywall sheets but also it’s joint compound. Asbestos can be found in drywall from 1930 and in joint compound from the 1940s until the 1980s. Although banned in the year 1977, asbestos can still be found for a few years later. Last week I inspected a home built in 1980 that had asbestos-containing joint compound.
US consumption of asbestos peaked in 1973 and the first bans began shortly after. While the dates listed for phased out asbestos-containing materials may be used as a guide, it should not be assumed that asbestos will be absent after those dates. Certain materials such as joint compound, vinyl floor tiles, and mastics have a long shelf-life and may have been stored away and used after the materials were phased out.
If you are unsure about a material in your home, visit our page for asbestos inspections. For more information about what to do after asbestos has been confirmed in your home, please refer to our previous entry on that topic. (https://indoorscience.com/blog/what-do-i-do-with-it/)
U.S. Federal Bans on Asbestos | Asbestos | US EPA
The History of Asbestos – Importing, Exporting & Worldwide Use
Protect Your Family from Asbestos-Contaminated Vermiculite Insulation | Asbestos | US EPA
Is There Asbestos Hiding in Your Walls? The Truth About Asbestos Drywall