SEATTLE — Chipotle Mexican Grill on Nov. 10 said it will begin reopening all 43 restaurants in the Pacific Northwest that the company voluntarily closed at the beginning of the month after more than 20 people became ill with E. coli. Chipotle said health officials have concluded there is no ongoing risk from the incident, and the company has replaced all ingredients in the closed restaurants with a fresh supply of new ingredients.

Steve Ells, chairman and co-CEO of Chipotle

“The safety of our customers and integrity of our food supply has always been our highest priority,” said Steve Ells, chairman and co-CEO of Chipotle. “If there are any opportunities for us to do better in any facet of our sourcing or food handling, from the farms to our restaurants, we will find them. We are sorry to those affected by this situation, and it is our greatest priority to ensure that we go above and beyond to make certain that we find any opportunity to do better in any area of food safety.”

In order to ensure its food is as safe as possible, Chipotle said it will take additional steps, including conducting additional deep cleaning and sanitization in all its restaurants nationwide; confirming that none of its employees in the affected restaurants had E. coli; testing fresh produce, raw meat and dairy items prior to restocking restaurants; and testing food, restaurant surfaces and equipment in its restaurants.

According to the Oregon Health Authority, as of Oct. 31, there were three reported cases in Oregon and at least 19 in Washington. One third of the cases have been hospitalized, but there have been no deaths. The most recent reported date that a meal was served that may have been linked with the incident was Oct. 24, Chipotle said.

During the investigation, Chipotle said it conducted independent testing in its restaurants and distribution center, assisted health authorities during all phases of the investigation, and retained two food safety scientists to help the company assess and improve upon its food safety standards.

The restaurant chain said no cause has been established between the outbreak and any ingredient.

“Both Chipotle and health officials have been conducting food and environmental testing in Chipotle restaurants and distribution centers, but tests have not confirmed a link to any ingredient,” Chipotle said.