The EPA said it's been working work Exxon Mobil to monitor air quality near Mayflower, Ark., the site last week's oil spill.
U.S. pipeline regulators estimated at least 3,500 barrels of crude oil spilled from the Pegasus pipeline, which can carries Canadian crude oil. Exxon said more than 10,000 barrels of an oil and water mixture have been removed from the site of the spill.
"As cleanup continues, contaminant levels continue to decrease," the EPA said. "To date, the air quality readings have been below levels likely to cause health effects for the general population with the exception of the cleanup areas where the emergency responders are directly working."
Benzene was detected by Exxon in early air quality samples.
The company said most of the free-standing oil has been recovered and local waterways remain oil free. A plan is in the works to get the damaged section of the pipeline out of the ground.
More than 20 homes were evacuated due to the spill. Exxon said the cause of the incident is under investigation.