Since the creation of the first central heating systems (HVAC), researchers as well as construction workers and the HVAC technicians themselves have tried many different materials to keep the heating ducts from leaking the heated or cooled air. After being used for years in thousands of HVAC units, lagging tape is still one of the products most commonly used. This tape can be found in the corners, crevices, and cracks of the heating ducts, in any area that may be susceptible to leakages.
During the first decades of use for HVAC system, this lagging tape was made largely from asbestos. The mineral was popular for a lot of things because it was strong and could resist fire and heat. Asbestos was also easy to get and relatively inexpensive. This helped reduce the overall cost of making any product used in construction for insulation.
When the 1970s came along, people who had been working with HVAC systems and using the asbestos lagging tape began to show certain health issues. Many of them were diagnosed with diseases related to asbestos like mesothelioma. This led to a number of lawsuits against the companies that manufactured products that contained asbestos.