The deadly flu outbreak in Mexico has 3M Co. racing to meeting rising global demand for its N95 respirator at a time when the Maplewood-based manufacturer has joined several other Minnesota companies in restricting travel there until more is known about the new virus.

3M spokeswoman Jackie Berry said the N95 respirator -- a form-fitting mask that was in high demand during the 2003 SARS outbreak in Asia -- is on back order. The company is accelerating production at plants in the United States, Latin America, Europe and Asia, she said. The respirators are stocked by hospitals and health-care organizations as well as businesses and governments.

"We significantly increased our production and are working hard to meet demand," Berry said.

The Centers for Disease Control and Prevention in Atlanta on Monday recommended that U.S. travelers forgo nonessential travel to Mexico, where 149 deaths have been linked to the flu outbreak so far.

Twin Cities companies, including 3M, Cargill Inc., General Mills Inc., Medtronic Inc. and Best Buy Co. Inc. are restricting or temporarily postponing travel to and from Mexico. Some companies are encouraging employees in Mexico to work from home if possible.

"This is a new strain and we will monitor it closely," Cargill spokesman Mark Klein said in an e-mail.

Cargill's facilities in Mexico continue to operate but the Minnetonka-based company has given parents there the flexibility to stay home and take care of children, as many schools were temporarily closed.

"We are telling employees that if they have non-essential travel to Mexico City or other affected areas in the country, that they should defer it a bit until we all know more information," Klein said.

It's a similar story with other Twin Cities employers.

Medtronic Inc. decided Monday to temporarily restrict travel to Mexico City and encourage those employees in Mexico who can work from home to do so. The Fridley-based medical device manufacturer has 2,700 employees in Mexico at its sales office in Mexico City and a stent assembly plant in Tijuana, said company spokesman Chuck Grothaus.

The Mosaic Co., a Plymouth-based manufacturer of agricultural fertilizer, said it has told its 10 employees in Mexico City to work from home until more is learned about the flu virus.

MoneyGram International Inc., the St. Louis Park-based money transfer company, has asked its employees to avoid all travel to Mexico "unless it's absolutely essential," said spokeswoman Lynda Michielutti.

MoneyGram, which operates in 190 countries, has about 12,000 branches in Mexico that provide money transfer services. Managers at the company occasionally travel from the United States to Mexico to provide training and to meet with potential clients. The company is now asking employees to conduct meetings via telephone or the Internet.

The Minnesota Pork Producers Association is working to deflect concern about the nation's pork supply. It referred calls to the Des Moines, Iowa-based National Pork Board, which said pork is perfectly safe to eat.

The Minnesota group posted this notice on its website: "National Pork Board is urging pork producers to enhance the biosecurity plans on their farms as the result of a new strain of the swine influenza virus type H1N1 being reported by the U.S. Centers for Disease Control and Prevention (CDC). The virus is unique and has not been seen in the U.S. swine herd. At this time, no pigs have been found to be infected or sick with the virus. It is unknown if this new strain causes any type of illness in swine. However, because it is novel, the National Pork Board is urging producers to take extra precaution to protect our industry's workers and our animals."

Just how much effect the flu will have on Minnesota businesses is anybody's guess.

"We don't know," said airline analyst Terry Trippler, president of Terrytrippler.com in Minneapolis. "No one knows how bad it [the contagion] is."

Travel companies continued fielding calls from travelers as many major U.S. air carriers, including Atlanta-based Delta Air Lines, are waiving change penalties. Delta is allowing travelers to make a one-time, penalty-free change to flights until May 4 for flights to, from or through Mexico. Company spokesman Anthony Black said Monday that Delta had seen minimal changes to bookings. Delta has not made any operational changes, he said, other than reminding crews in targeted areas to be vigilant about hand-washing and other cleaning procedures.

Delta flies six flights each day to Mexico City, from Atlanta, New York, Detroit and Salt Lake City.

George Wozniak, president of Hobbit Travel, said the outbreak's immediate impact on the U.S. travel industry is limited by the fact that summer is a slow season for Mexico travel. Hobbit currently has an agent in Acapulco attending Tianguis Turístico, a major annual tourism trade show sponsored by the Mexican government, Wozniak said. The show attracts thousands of people. He said he'd heard that bars and clubs in Acapulco have shut down in response to the outbreak.

"I wonder what they're doing now at night, all these people," he said.

La Jornada, a major Mexican newspaper, reported that President Felipe Calderon had suspended his plans to visit the trade show in Acapulco.

Star Tribune staff writers Christopher Serres, Matt McKinney and Steve Alexander contributed to this report.

Jennifer Bjorhus • 612-673-4683