Frank Popoff, who as chief executive and chairman tried to make Dow Chemical more conciliatory toward regulators and environmentalists in the late 1980s and ’90s, and who prodded the chemical industry to adopt safer practices, died on Feb. 25 at his home in Midland, Mich., where Dow is based. He was 88.

A spokesman for the company said the cause was cancer.

When the Bulgarian-born Mr. Popoff was named Dow’s president and chief executive in 1987, the company had begun trying to shed its image as a pugnacious chemical giant that had manufactured napalm and the defoliant Agent Orange for the U.S. military during the Vietnam War; released toxic waste, like dioxins, into the Tittabawassee River from its plant in Midland; and fought the Environmental Protection Agency to prevent flyover inspections of its emissions.

An estimated $50 million advertising campaign, begun two years before Mr. Popoff rose to the top, used the slogan “Dow lets you do great things.” It was intended to change public perceptions of Dow, promoting an image of it as a nicer corporation, underlining its charitable giving and humanitarian uses of its products.

“I think we have a fair amount of work to do in terms of the way we are viewed,” Mr. Popoff told The New York Times in 1987, shortly before succeeding Paul F. Oreffice as chief executive. “We know we’ll never change Ralph Nader’s mind. But Dow is at peace with itself, and we want our people to feel good about the company, too.”

The company was best known then for manufacturing chemicals, including chlorine, as well as for using chemicals in making plastics, pharmaceuticals and supermarket goods like Saran Wrap, Fantastik cleaning liquid and Ziploc bags.

Regulators and environmentalists were heavily focused on chemicals at the time. In 1991, Mr. Popoff and another Dow executive, David Buzzelli, set up a panel of outside environmental policy advisers — among them Lee Thomas, a former E.P.A. administrator — who scrutinized Dow’s operations and were able to obtain confidential information. A current version of that panel remains in place at Dow.

Between 1988 and mid-1991, Dow reduced by almost one-third its emissions of 121 harmful chemicals that the E.P.A. had tracked, and the company was on the way to its goal of cutting emissions by one-half.

“I’m in the chemical business,” Mr. Popoff told The Detroit Free Press in 1992. “That’s synonymous with a lot of bad things. But I’m for environmental responsibility.”

In a speech to the Economic Club of Detroit a year later, he elaborated on the need for Dow to be open to ideas from regulators and environmental activists. “There is no alternative to environmental reform in our industry,” he said, arguing that chemical companies should lead such efforts or be forced to deal with poorly designed regulations.

Carol Browner, who was the E.P.A. administrator at the time, recalled in an email that Dow was “easier to work with” under Mr. Popoff. But when she suggested in 1994 that the agency wanted to “substitute, reduce or prohibit” the wide use of chlorine and chlorinated products within three years, Mr. Popoff sent a testy letter to President Bill Clinton.

“It would be irresponsible to pursue a policy that presumes all chlorine products are bad without considering either the weight of scientific evidence on chlorine chemistry or the economic ramifications of a chlorine ban,” he wrote. He added: “The decision to pursue such a sweeping approach to this very complicated issue was reached without industry’s participation. The Dow Chemical Company is committed to constructive participation.”

Jack Doyle, who wrote “Trespass Against Us: Dow Chemical & The Toxic Century” in 2004 for the Environmental Health Fund, an advocacy group, said in an email that chlorine was too important to Dow’s bottom line for the company to give it up without a battle.

Dow’s commitment to the chlorinated industry was “so dominant and so woven into the world’s economy,” he added, “that making any real dramatic changes were out of the question.”

Frank Popoff, whose given name was Pencho, was born on Oct. 27, 1935, in Sofia, Bulgaria, to Eftim Popoff, who was also known as Frank, and Stoyanka (Kossoroff) Popoff, who was called Stany.

He emigrated to the United States with his parents and sister in 1939, and they settled in Terre Haute, Ind., where his parents ran a dry-cleaning business.

Inspired by a high school teacher who had been gassed while fighting in World War I, Mr. Popoff studied chemistry at Indiana University, where he earned bachelor’s and master of business administration degrees in the same year, 1959.

He did not want to be a chemist, however.

“Perhaps I lacked the creativity and the vision that successful chemists have,” he said in an interview in 2012 with the Chemical Heritage Foundation in Philadelphia (now the Science History Institute). “I was really interested in the commercialization and application of chemistry.”

He joined Dow in 1959 and stayed with the company for 41 years. He worked in its urethane laboratory, then in technical services and chemical sales in the early 1960s. He would later move into increasingly influential positions: president of Dow Europe in 1981, executive vice president of Dow Chemical in 1985 and, two years later, president and chief executive. He was named chairman in 1992.

Under Mr. Popoff, Dow Chemical expanded its Asian operations and bought a majority stake in the drugmaker Marion Laboratories in 1989 (it was renamed Marion Merrell Dow) before selling it six years later amid patent expirations and heavy competition.

In the early 1990s, Dow Chemical became enmeshed in controversy over the safety of silicone breast implants made by Dow Corning, its joint venture with Corning Inc.

“Rightfully or wrongfully, there are a lot of people outraged about the implants,” Mr. Popoff told The Free Press in 1992. But, he added, “Our liability is limited to that of a shareholder, because that’s what we are.”

In 1995, however, the company was found liable by a Nevada jury for more than $14 million in damages after a woman suffered health problems caused by leaky implants. The next year, the New York State Appellate Division ruled that Dow Chemical was not liable in 1,400 lawsuits over the implants.

Mr. Popoff stepped down as chief executive in 1995 and as chairman in 2000. He later taught at Indiana University for a time and served on corporate boards.

He is survived by his wife, Jean (Urse) Popoff, whom he met in college and married in 1958; three sons, John, Thomas and Steven; and four grandchildren.

Jim Fitterling, the current chairman and chief executive of Dow, said that Mr. Popoff’s most important achievements revolved around making safety a critical goal — “not that it wasn’t important, but he put it front and center” — and being an early proponent of sustainability. That included generating less waste, consuming fewer resources and better ensuring employee safety. He helped advance a voluntary industrywide code of conduct, called Responsible Care, which formalized those principles.

But Mr. Popoff said it wasn’t always easy to get other companies to comply. Early on there was pushback.

“Some things had more impact for large companies versus small companies,” he told the Science History Institute. “Then the hard work began, that of making sure everyone was compliant. And what can you do? You can use whatever bully pulpit you have to assure other people that it is not only in their best interest, but it’s mandatory for the industry to survive without pulling down the animosity and the ill will of society, which the chemical industry on occasion is capable of doing.”