3M Co. said it is racing to meet demand for it N95 respiratory masks amid surging demand brought on by the outbreak of swine flu.

Spokeswoman Jacqueline Berry said the masks are now on back order -- meaning the Minnesota-based company doesn't have enough of them on hand to ship to all the customers who want them. "We've significantly increased production and we are working hard to meet the demand," she said.

Ms. Berry said 3M has ramped up production at facilities in all of its regions, including the U.S., Latin America, Europe and Asia/Pacific. She said the company had added shifts and new production lines to increase output, but she declined to quantify the increase or say how many masks the company normally makes.

-- Joe Barrett