Firefighters who responded to a blaze at a vacant Oklahoma City elementary school were exposed to asbestos, authorities said.

The crew responded to the fire at Columbus Elementary School early in the morning of October 16. They found a pile of trash burning in the school’s basement.

Upon finding asbestos on site, authorities called in a hazardous materials unit to decontaminate any firefighters who had been exposed to asbestos.

The Columbus Elementary building has been vacant since hosting its last classes in June 2014, when the school moved to a new location. The original, over-100-year-old building had been used as an elementary school since 1910.

Historical Use of Asbestos

At the time Columbus Elementary was built, the construction industry used asbestos in construction materials whenever possible. It offered natural insulation and fireproofing properties in addition to being inexpensive and readily available. It found its way into insulation, cement, construction adhesives, ductwork parts, and floor backing materials.

At the same time, the medical community had become aware of the health hazards associated with asbestos since as early as the late 19th century.

Research through the first half of the twentieth century revealed more and more cases of asbestos lung cancer and mesothelioma, and in 1964 the first case of mesothelioma definitively linked to asbestos exposure was recorded. Yet throughout that period, commercial and industrial use of asbestos only increased.

Today, asbestos is associated with several different deadly respiratory diseases like lung cancer and mesothelioma. These diseases have a very long latency period, which is the time between the exposure to asbestos and the development of the disease to a point at which it can be diagnosed. Some cases of asbestos disease take as much as 50 years to develop. So a person can develop asbestos disease today based on exposure from way back in the mid-20th century.

Federal Asbestos Regulation

Despite the health risks, asbestos is still not completely banned in the U.S., and it’s still possible to be exposed to asbestos today. The U.S. Environmental Protection Agency began restricting asbestos use in the early 1970s with regulations that banned certain asbestos-based fireproofing and insulation materials.

The Consumer Product Safety Commission also enacted a ban on certain household products that sometimes contained asbestos, like artificial fireplace embers and wall patching compounds.

In 1989, the EPA attempted to enact a ban on the manufacture, importation, processing, and distribution of most asbestos-containing products. But in 1991, a federal court vacated and remanded that rule.

The court said that ban failed to comply with a requirement under the Toxic Substances Control Act that regulation of a material must be the “least burdensome” means of controlling that substance.

Today, perhaps contrary to many consumers’ understanding, U.S. asbestos regulation is piecemeal. Some products that have historically contained asbestos can still be manufactured and sold with some asbestos content. The list of such products includes many common construction materials like cement pipe, cement shingle, vinyl flooring tile, and roofing felt.

Many automotive parts are also still manufactured with asbestos. Parts that must withstand large amounts of heat or friction, like gaskets, clutch facings, brake blocks, disc brake pads, drum brake liners, and parts of automatic transmissions, can still be made with asbestos.