Intel’s failure to report its fluoride emissions in Washington County to the state for years was an “inadvertent oversight,” a company spokeswoman said Friday in a written statement.

The chip-making company has been emitting fluoride since 1978, but only recently added the pollutant to an air quality permit application with the state. Company spokeswoman Chelsea Hossaini said in a statement to The Oregonian that the company notified the state’s Department of Environmental Quality about the omission in 2012.

The statement also said an Intel analysis showed the fluoride levels would have been below significant state emissions levels. But the company declined to provide a tonnage per year in emissions, which determines whether an emission is significant. Hossaini said the company had no further comment.

“Fluoride is unfortunately a bit of an oversight,” state environmental engineer George Davis told Hillsboro residents at an Intel air permit meeting this week. “It should have been in the permits in the past. We’re correcting that oversight now.”

Davis added that it was a “bad oversight” but not a violation.

The admission comes as Intel is applying for a new air quality permit in Washington County that will increase its volatile organic compounds limit and add greenhouse gases and fluoride to its current permit.

Greenhouse gases, which Intel emits in large quantities, were added to a list of regulated pollutants in 2011 and that prompted the company to seek a different type of permit with DEQ. In compiling information for the air permit application, Intel officials realized the company’s fluoride emissions “triggered reporting requirements,” according to the statement.

The company plans to emit up to 6.4 tons per year of fluoride” as part of its $3-billion expansion in Hillsboro. That cap is more than the 3 tons per year considered a “significant emission.”

DEQ approved the company’s massive expansion in 2010 before greenhouse gases were a regulated pollutant. Once the gases became regulated, Intel was deemed a “federal major source.” That classification comes with a slew of Environmental Protection Agency regulations to discourage excess pollution. But because the classification was triggered after Intel had gotten DEQ approval, the company’s expansion isn’t bound by regulations under the EPA’s Prevention of Significant Deterioration program.

When Intel applied for D1X approval it did not include its fluoride emissions.

In Hossaini’s statement, she said “changes are being implemented at Intel” because of regulations. She declined to offer specifics.

A public hearing for the company’s air quality permit will be held Monday in Hillsboro.