Samuel Johnson, 76, a Wisconsin entrepreneur and philanthropist who amassed a multibillion-dollar fortune while chairman of S.C. Johnson & Son Inc., a leading maker of bug sprays, household cleaners and personal grooming products, died May 22 at his home in Racine, Wis. He had cancer.

Mr. Johnson, who was listed in Forbes magazine last year as the 25th-richest American with a net worth of $7.4 billion, ran one of the country's largest family-controlled companies from 1967 until his retirement in 2000. He had served as chairman emeritus since retiring.

A native of Racine, he was the fourth generation in his family to run the business. It had been founded by his great-grandfather in 1886 as a manufacturer of parquet flooring.

The company, which later became more commonly known as SC Johnson, soon went from making and selling parquet flooring to producing a specialty paste wax for maintaining floors.

Mr. Johnson, who was known as Sam, was a graduate of Cornell University and Harvard Business School. He served as an intelligence officer in the Air Force before joining the family business, based in Racine, in the mid-1950s.

He initially worked as an assistant to his father, Herbert Johnson Jr., then president of the company, before moving to the product development division. There, the younger Mr. Johnson made his first mark on the company by overseeing a watershed moment: the creation of a formula for Raid House and Garden Bug Killer. The popular insecticide and Johnson Wax became among the company's best-selling consumer products.

SC Johnson's product line expanded further in the 1950s, adding Glade air fresheners, Off! mosquito repellant and Pledge furniture polish. Later, through acquisitions of other companies, SC Johnson began producing such well-known brands as Windex, Drano, Ziploc and Fantastik.

From its corporate headquarters, a modern concrete-and-brick building designed by Frank Lloyd Wright, Mr. Johnson enhanced the company's culture, known for its employee friendly atmosphere. SC Johnson routinely made Fortune's list of the top 100 Best Companies to Work For, citing its employee profit-sharing program and employee use of a vacation resort in northern Wisconsin.

Mr. Johnson earned a reputation as a leading corporate environmentalist for adopting policies to reduce pollution at its plants and increase recycled packaging. In 1975, he voluntarily banned the use of chlorofluorocarbon propellants in its aerosol cans, years before the government made it mandatory.

He also presided over a diversification of the family empire, creating a financial services company and a recreational products manufacturer. In one of his final acts as chairman, he devised a plan to pass the family empire to his children as a way to head off potential squabbling.

A self-effacing business executive who shunned pomp and circumstance, Mr. Johnson was praised for speaking openly about his alcoholism in a documentary film, "Carnauba: A Son's Memoir." The movie documents Mr. Johnson's efforts in 1998 to re-create a flight his father made in the 1930s from Racine to Brazil in search of the rare carnauba palm, a renewable source of wax.

He gave generously to a wide range of charitable, nonprofit and educational organizations, including a $1 million donation to the Smithsonian Institution for the IMAX theater.

Survivors include his wife, Imogene Johnson; four children; a sister; and 15 grandchildren.

Samuel Johnson, chairman emeritus of SC Johnson, was an environmentalist who rallied opposition to a power-plant expansion in Racine, Wis.