Early construction of the twin towers used asbestos. Contractors used asbestos materials in the lower floors of the North Tower, before the dangers of asbestos exposure became widely recognized in the early 1970s. In early April 1970, the New York City Department of Air Resources established asbestos spray insulation regulations.

Contractors using asbestos insulation in the twin towers failed to comply with these regulations. As a result, the Department ordered contractors to stop all asbestos use in the World Trade Center.

The upper levels of the North Tower and the entirety of the South Tower contained asbestos alternatives.

Why Was There Asbestos in the Twin Towers?

Asbestos was used in the twin towers mainly for insulation. The mineral also offered strength, fire resistance and heat resistance to the tower’s infrastructure.

Contractors applied spray insulation to the steel beams in the lower levels of the North Tower for strength and fireproofing. The steel and concrete framework held up the towers, supporting elevator shafts and stairwells.

In addition to insulation, other suspected uses of asbestos-containing products include cement, flooring and foam board.

How Much Asbestos Was in the World Trade Center?

The North Tower contained an estimated 300 – 400 tons of asbestos. The twin towers also contained many contaminants. In total, the buildings were constructed with 424,000 tons of concrete and 485,000 tons of other materials.

Was Asbestos Removed from the World Trade Center?

The Port Authority of New York and New Jersey instated regulations for asbestos use and abatement in 1971. Early estimates of asbestos abatement from the World Trade Center totaled close to $1 billion.

In the mid-1980s, Port Authority undertook an extensive asbestos-removal program to remove the mineral from the World Trade Center. Because asbestos was used in the framework of the buildings, removal was difficult and expensive.

Information regarding asbestos abatement from the twin towers is limited. Some reports indicate the program was able to remove some of the asbestos. However, testing of 9/11 dust and rubble confirms much of the mineral still remained.

02. Asbestos Exposure

The Twin Towers and Asbestos Exposure