I think you're missing the point. This is a substance that has been shown to cause cancer, and other things, and that should be mentioned in an EPA report, not censored out of it. The article does discuss the severity of the cancer risk, as below.
In a version of the document entered into the division’s computer system on December 17, the toxicologist had included the information about PCBTF, noting that the chemical can be absorbed through the lungs, gastrointestinal tract, and skin. He also identified cancer as one of its hazards, along with liver, kidney, lung, and adrenal gland effects, and calculated the cancer risk associated with precise amounts of the paint. But the next day, hours after the contentious meeting in which the official had tossed the memo, she inserted a note into the assessment, asking the assessor to delete all references to PCBTF.
It was one of the things censored from the report.
Name something that doesn't cause cancer. California requires that every business that could expose you to carcinogens have a notice in public view. Problem being, the list of carcinogens is so long that literally no business can avoid the warning, so everyone ignores the notices because they're meaningless.
Unfortunately this article fails to make clear the severity of the carcinogen risk. If I understand the risk of aspartame (the zero-calorie sweetener) correctly, it was shown to cause something like 4% increase of cancers in rats... given a dose that, adjusted for body weight, would be on par with a few hundred cans of soda per day. Is this stuff more dangerous? Less? Hard to tell.
At the end of the day, there are pros and cons to everything. This thing reduces greenhouse gasses; yay. It has some other deleterious effect? Go figure. There are no magic bullets to solve all our problems, just an infinite plateau of priorities to juggle. So which is more important? Cutting greenhouse gasses, cutting cancer, or avoiding a substance with some utility? Cooking food makes it carcinogenic. Is it better to eat raw foods to avoid cancer? I doubt it. E. coli in the chicken is probably a bigger risk. For sweeteners we have to decide whether it is better to cut calories and risk cancer, accept the calories for a miniscule drop in cancer risk, or forego sweeteners and happiness altogether.