The agency alleged that OSCO failed to adequately control carbon monoxide gas emissions from both plants. During the past five years; emissions from the Portsmouth plant were not burned at the required temperature on 390 days, and emissions from the Jackson plant were not burned at the required temperature on 858 days.

"EPA's mission is to protect public health and the environment," said Acting Regional Administrator Bharat Mathur. "We will take whatever steps are needed to ensure compliance with the Clean Air Act."

These are preliminary findings of violations. To resolve them, the EPA may issue a compliance order, assess an administrative penalty or bring suit against the company. The company has 30 days from receipt of the notice to meet with the EPA to discuss resolving the allegations.

When carbon monoxide enters the bloodstream, it reduces delivery of oxygen to the body's organs and tissues. Exposure to high levels of carbon monoxide can cause death or impair vision, hand movement, learning ability and performance of complex tasks. Persons with heart disease have the greatest risk when exposed to this pollutant.