Paul F. Oreffice, who as the pugnacious head of Dow Chemical grew and diversified the company at the same time that he rebuffed Vietnam veterans over Agent Orange, argued that the chemical dioxin was harmless and oversaw the manufacturing of silicone breast implants that were known to leak, died on Dec. 26 at his home in Paradise Valley, Ariz. He was 97.

His family confirmed his death.

Mr. Oreffice (pronounced like orifice) spoke in staccato, fast-paced sentences, and they were often deployed in pushing back against environmentalists, politicians and journalists during an era, the 1970s and ’80s, when the environmental movement was gaining force by focusing on toxic chemicals in the air and water.

Under his 17-year leadership, which included the titles of president, chief executive and chairman, Mr. Oreffice weathered intense controversies.

His public relations instinct was for confrontation, not conciliation. He had an intense dislike for what he perceived as government meddling in business, which he traced to his having grown up in Italy under Mussolini. “I’ve seen what overgoverning can do,” he told The New York Times in 1987. “I was born under a Fascist dictatorship, and my father was jailed by it.”

Mr. Oreffice took the reins of the Dow USA division in 1975, when its public image was tainted from campus protests of the 1960s that had vilified the company as a maker of the incendiary agent napalm, which was widely used in Vietnam.

When Dow pulled out of apartheid South Africa in 1987 under pressure from shareholders, Mr. Oreffice said: “I’m not proud of it. I think we should have stayed and fought.”

In 1977, when Jane Fonda lacerated Dow in a speech at Central Michigan University, not far from Dow headquarters, in Midland, Mich., Mr. Oreffice canceled the company’s donations to the school, writing its president that he could not support Ms. Fonda’s “venom against free enterprise.”

Instead, Mr. Oreffice financed the campaigns of anti-regulation politicians. And he sued the Environmental Protection Agency for surveilling Dow’s sprawling Midland plants from the air when the company refused an on-site inspection.

The case made its way to the United States Supreme Court, which in 1986 ruled against the company, at the time the No. 2 American chemical maker after DuPont. (The companies merged in 2017, then split into three companies.)

In 1983, Rep. James H. Scheuer, Democrat of New York, disclosed that Dow had been allowed to edit an E.P.A. report on the leakage of dioxin, one of the most toxic substances ever manufactured, from the Midland plants into the Tittabawassee and Saginaw Rivers and Saginaw Bay.

E.P.A. regional officials told Congress that their superiors in the Reagan administration ordered the changes to comply with demands made by Dow. Mr. Oreffice, appearing on NBC’s “Today” show, offered a sweeping dismissal.

“There is absolutely no evidence of dioxin doing any damage to humans except for causing something called chloracne,” he said. “It’s a rash.”

His statement brushed aside evidence that dioxin was extremely hazardous to laboratory animals and had been shown in some research to be linked with a rare soft-tissue cancer in humans.

One former Dow president, Herbert Dow Doan, a grandson of the company founder, told a public relations publication, Provoke Media, in 1990 that Mr. Oreffice’s style was not one fine-tuned to mollify critics. “The reason is part ego, part pride,” he said. “Paul is inclined to push his line to the point where some people say he is arrogant.”

There is no question that Mr. Oreffice’s strength of will also uplifted Dow’s businesses, which through the 1970s were overly dependent on basic chemicals like chlorine. When a glut of low-priced petrochemicals flooded the global market in the early 80s, he aggressively reshaped Dow by diversifying into consumer products, such as shampoos and the cleaning fluid Fantastik, and by moving into foreign markets. By 1987, Dow posted a record profit of $1.3 billion (about $3.5 billion in today’s currency).

At the same time, a class-action lawsuit on behalf of 20,000 Vietnam veterans and their families against Dow and other makers of Agent Orange was further tarnishing the company’s image. The suit, filed in 1979, charged that dioxin in Agent Orange led to cancer in combat veterans and genetic defects in their children.

Dow argued that it had made Agent Orange at the request of the government and was not responsible for how it was used. But in 1984, the company and other makers of Agent Orange, without admitting liability, settled the lawsuit for $180 million, with the proceeds going to veterans and their families.

In another controversy, Dow Corning, a joint venture between Dow Chemical and Corning Inc., released documents in February 1992 showing that it had known since 1971 that silicone gel could leak from breast implants it made.

Tens of thousands of women had sued the company, claiming their implants had given them breast cancer and autoimmune diseases. Dow Corning agreed to a $3.2 billion settlement after the company had been driven to file for bankruptcy protection.

In 1999, an independent review by an arm of the National Academy of Sciences concluded that silicone implants do not cause major diseases.

Paul Fausto Orrefice was born Nov. 29, 1927, in Venice. His parents, Max and Elena (Friedenberg) Oreffice, moved the family to Ecuador in 1940 as Mussolini declared war on Britain and France. Paul came to the U.S. in 1945, entering Purdue University with fewer than 50 words of English at his command.

He graduated with a B.S. in chemical engineering in 1949, became a naturalized citizen, and after two years in the Army went to work for Dow in 1953.

“When I walked into Midland, Mich., this was ‘WASP’ country, and I was a ‘W’ but I wasn’t an ‘ASP,’” he told The Washington Post in 1986. “I spoke with an accent and combed my hair straight back, which just wasn’t done.”

Mr. Oreffice represented Dow in Switzerland, Italy, Brazil and Spain before being called back to the Midland headquarters in 1969 and appointed the company’s financial vice president. He became president of Dow Chemical U.S.A. in 1975 and was then promoted to president and chief executive of the parent Dow Chemical Company in 1978. In 1986, he added the title of chairman.

To the astonishment of many observers, Dow poured millions of dollars in the mid-1980s into a public-relations campaign to improve its image, including a new slogan, “Dow let’s you do great things.”

Under company rules, when he reached age 60, Mr. Oreffice stepped down as president and chief executive in 1987. He retired as chairman in 1992.

He is survived by his wife of 29 years, Jo Ann Pepper Oreffice, his children Laura Jennison and Andy Oreffice, six grandchildren and one great-granddaughter.

In retirement, Mr. Oreffice pursued a passion for thoroughbred racehorses, investing in Kentucky Derby starters and spending summers at a home in Saratoga Springs, N.Y. He was a partner in a Preakness Stakes winner, Summer Squall, and a Belmont Stakes winner, Palace Malice.

In 2006, he published a memoir about rising from an immigrant with little English to a corporate titan, titling it “Only in America.”