Lack of asbestos fireproofing (FP) on structural steel could have played a role in the WTC collapse but the source of that argument, proponents of Junk Science and Herbert Levine, are on shaky ground. I've responded to their WTC asbestos-lack argument elsewhere, my main point being that asbestos is only one of several reliable, equally effective, FP materials available -- though asbestos is one of the oldest and the one with the most long-lived die-hards.
(The asbestos industry for over a century promoted its material as a solution to a wide range of hazards, and battled in court repeatedly against those who disagreed -- the comparison with tobacco is apt. And like tobacco, an amazing number of its advocates died from exposure to the material so avidly promoted.) The problem all FP materials share is that of inept installation and poor maintenance, and none are effective if improperly installed and protected against deterioration as was the case with WTC -- not that WTC is unique in this. The installation and maintenance of FP materials in WTC has been documented as poor. Had the material been asbestos not much would have been different, and might have been worse. Installation of asbestos has been long known as poor, not least because the industry made it appear that even poor asbestos installation was superior to any other type. Not true. Independent testing laboratories set standards for FP and rate all materials by the same methodologies -- giving each system a fire-rating based on its resistance to fire and heat -- 1 hour, 2 hour and so on. Various parts of buildings are required by building codes to be fire-proofed for a set hourly resistance, e.g., 3-hours for floors and their supporing structure, 2-hours for interior walls acting as fire separations or mechanical system enclosures, 1-hour for hazardous materials storage. However, over time due to subsequent alterations, installations of mech/elec systems, and building movement, FP is often damaged and needs restoration to maintain its effectiveness. That does not happen. I see deficient FP in every building I inspect, my own work not excepted. You have to battle to get contractors to do it right. And owners to pay for quality work and maintenance rather than wait for vicitms and insurance companies to pay the tithe of negligence. The Port Authority is a negligent landlord and Silverstein is no better. But they are the norm for Junk Property Owners who promote attacks on Junk Science as a cover for their criminal venality. And in this they are kissing kin of the asbestos industry ghouls.