Amphibole and tremolite are related forms of contaminant asbestos that are extremely toxic in nature. However, the U.S. Environmental Protection Agency (EPA) has not specifically listed these asbesti-forms in the Clean Air Act (CAA) or its implementing regulations because they are not commercially produced. This exclusion is difficult to justify in light of the well-established link between exposure to these contaminants and asbestos-related disease. This Note discusses the regulatory loophole created by the current CAA regulatory scheme and uses the pending criminal action against W.R. Grace & Company to expose the need for regulations in this area. This Note calls for EPA to promulgate explicit regulations on contaminant-asbestos. Absent regulatory action, this Note urges courts to interpret the CAA in accordance with congressional intent to ensure that the knowing emission of hazardous pollutants does not go unpunished.