Asbestos in Air Ducts & HVAC: A Complete Guide

The use of asbestos in air ducts began as early as the 1920s and continued until its dangers became widely known in the 1980s. Because they were frequently exposed to asbestos, workers who installed or repaired heating, ventilation and air conditioning (HVAC) systems during this time are at high risk for developing mesothelioma and other serious illnesses.

If you were exposed to asbestos in air ducts and diagnosed with mesothelioma, you may be able to get compensation. In this article, we’ll cover everything you need to know about HVAC and asbestos.

Asbestos Use in Air Ducts

Air ducts connect the rooms of a home or building to its HVAC system. They’re made up of wide, metal pipes, connected by flexible duct connectors and wrapped in insulation. Asbestos in HVAC parts made them more durable and heat-resistant, and it was flexible enough to weave into fabric and tape. Asbestos was used in buildings all over the U.S. for much of the 20th century.

In 1980, the Environmental Protection Agency (EPA) implemented strict regulations for the use, handling and disposal of asbestos products. At the same time, consumers became more aware of its dangers. Although the EPA still has not passed a total asbestos ban, these two factors effectively spelled the end for asbestos ducting.

However, HVAC systems that already contained asbestos were not removed or replaced. Many homes and buildings may still harbor this hidden health hazard in various HVAC parts, including:

Asbestos Insulation & Wraps

Insulation and wraps were applied to boilers, ducts, pipes and interior components of HVAC systems to prevent heat loss and condensation. Paper and cloth insulation were some of the most popular uses for asbestos in HVAC systems. Insulation typically contained about 15 percent chrysotile, the most common type of asbestos.

Asbestos Adhesive & Sealant

Asbestos in air ducts is also often found in the adhesives used to seal HVAC systems. Adhesive was usually applied around the connectors where the pipes bend or come together, as well as where the ducts connect to the wall. Spray-on and plaster adhesives were sometimes used, but asbestos tape was more common. It was completely wrapped around the ducts to create a strong seal.

Asbestos Millboard & Dampeners

Two more specialized HVAC parts often contained asbestos. Millboard, a wood-like product, is used to shield the walls and ceilings around HVAC systems from heat and used to be made with asbestos. Vibration dampeners are applied between metal parts in air ducts to reduce the noise caused by the system. Today they’re made with coated fiberglass cloth, but before 1980 they were often made of cloth woven with asbestos.

Health Risks of Asbestos in HVAC Systems

Asbestos is a mineral that contains long, thin fibers. They’re invisible to the naked eye, and they have no taste or smell. When they’re inhaled, they get stuck in the lungs and can travel to other parts of the body, where they cause inflammation, scarring and even changes to the cells. This leads to asbestos-related diseases like mesothelioma, asbestosis and lung cancer.

Asbestos in air ducts is hazardous because it’s friable, which means it can be easily disturbed. If you touch or move asbestos insulation or tape, especially if it has degraded over time, you could release the fibers into the air. Ducting also pushes air to all different parts of a building, making it especially dangerous if there is asbestos in the HVAC system.

Who Is at Risk for Exposure?

Exposure at work is the number one cause of mesothelioma and other asbestos-related illnesses. The occupations most at-risk from asbestos in air ducts include anyone who installed, repaired or replaced heating ducts or currently works with them, including:

  • Boiler workers
  • Construction workers
  • Demolition contractors
  • Duct installers
  • Electricians
  • Firefighters
  • HVAC workers
  • Insulation factory workers
  • Insulation installers
  • Metal workers
  • Pipefitters
  • Plumbers
  • Steamfitters
  • Steel workers

While today there are strict procedures for those who work with asbestos ducting, before the 1980s it was common for workers to bring home asbestos on their shoes and clothing. Therefore, family members of workers were also at risk of secondary asbestos exposure.

Identifying Asbestos in Air Ducts

It’s extremely difficult to tell by appearance whether metal products like the ducts themselves contain asbestos. Asbestos insulation appears fibrous, as if it has strings or fabric within it. Asbestos tape is often white or gray and is thicker than modern duct tape. It’s best not to rely on appearance when trying to determine if you have asbestos in your HVAC system.

Another way to identify asbestos air ducts is by manufacturer. The following is a list of known asbestos companies that produced ducting and other HVAC parts:

  • Celotex Corporation
  • Duro Dyne
  • Georgia-Pacific
  • Grant Wilson
  • H.B. Fuller
  • Johns Manville
  • Nicolet
  • Rich Tex
  • Turner & Newall
  • W.R. Grace

In general, it’s safest to assume that any HVAC system installed before the mid-1980s contains asbestos, and have it tested. Because there are so many different parts that could contain asbestos, this is a job for a licensed professional contractor.

Preventing Exposure to Asbestos

Asbestos is only a health hazard when it becomes airborne, which is why it’s most dangerous to HVAC workers and others who repair or install these systems. Today, high-risk occupations must follow strict protocols for ventilation, protective equipment, sanitization and disposal to help prevent exposure.

Despite their lower risk of exposure, many homeowners worry about asbestos in air ducts and other parts of the home. If you’re concerned about this, or if you plan to clean, repair or otherwise disturb your HVAC system, you should have it inspected and tested by a professional asbestos abatement contractor.

If asbestos is found, it should be dealt with by a professional. If it’s a small amount of damage, for example a few inches of insulation or adhesive that is breaking down, it can likely be sealed with a coating or covered with a special fabric. This is generally a better option than disturbing asbestos ducting. However, larger amounts will need to be removed by a professional.

Compensation for Mesothelioma Victims

Globally, 125 million people per year continue to be exposed to asbestos at work. Before the mid-1980s, the number was much higher. Because asbestos can take decades to cause health problems, many workers have been exposed without even knowing it.

Asbestos exposure is the only cause of mesothelioma. If you’ve been diagnosed, you may be entitled to compensation from the product manufacturer to help cover your treatment expenses and other pain and suffering.

Early, Lucarelli, Sweeney and Meisenkothen has decades of experience in this specialized area. We’ve fought for victims in court and won mesothelioma compensation in the millions, including $3.4 million for an Oklahoma HVAC worker and $2.6 million for a Navy veteran and HVAC worker in California. Contact one of our advocates today to learn how we can help you.


What are the health risks of asbestos in air ducts?

If it becomes airborne and is inhaled, asbestos in air ducts, insulation, duct tape and other materials can cause diseases like mesothelioma, lung cancer and asbestosis. You won’t know if you’re inhaling asbestos fibers, and health problems can take decades to appear. That’s why it’s so important to test air ducts for asbestos and leave cleaning, repair and removal to a professional.

How can I identify if there is asbestos in my air ducts?

It’s impossible to identify asbestos in air ducts from visual inspection alone. Although asbestos insulation and tape may appear frayed or stringy, that alone doesn’t indicate asbestos. It’s best to assume that any HVAC parts installed before the mid-1980s contain asbestos, and have them tested before proceeding with any projects.

Can asbestos in air ducts be safely removed?

Asbestos in air ducts can only be safely removed by a licensed professional asbestos abatement contractor. Because asbestos is easy to inhale and is a health hazard, homeowners shouldn’t attempt to remove or repair it by themselves.

Request a Free Case Evaluation

Request a free case evaluation now if you or someone you love has been diagnosed with mesothelioma. The evaluation will cost you nothing. Our lawyers will travel to visit you at your convenience or conference call with you over the phone. We understand how difficult a time this is for you and will assist in any way that we can. You can also call us toll-free at 1-800-336-0086 at any time.