Asbestos, a natural mineral that is responsible for a rare and aggressive form of cancer known as mesothelioma, has been historically used in thousands of products. It was used so extensively because it is flexible, durable, resistant to fire, and cheap. Because of its wide use, millions of people have been exposed to the asbestos fibers that can be easily inhaled or ingested, becoming lodged inside the body.
One such product in which asbestos was used was welding blankets. It was woven into the fabric because it was both durable and heat resistant. Welding results in a lot of sparks, which could easily catch the clothing worn by welders on fire, and these asbestos welding blankets were flame retardant. Not only were the welding blankets dangerous because they were made with asbestos, but there was the added danger of asbestos fibers breaking free from welding rods and landing on the blanket.
Generally, when contained within the blanket, asbestos fibers were not harmful, but as the blankets would wear down over time with use, the danger that those fibers would be released into the air increased. Fireproof welding materials are no longer manufactured using asbestos in the United States, so older welding blankets should be carefully disposed of according to federal and state regulations.