1968: P&G researcher Robert Volpenhein and his supervisor, Fred Mattson, were studying fat digestion and absorption in Miami Valley Labs when they ran an experiment giving enzymes different kinds of fat. When the resulting fat, called sucrose polyester, was not broken down in the body by enzymes, the two knew they were on to something: a fat that was not digested by the body.
1971: P&G begins talking informally with the Food and Drug Administration (FDA) about use of sucrose polyester, then dubbed olestra.
1975: In what is later viewed as a strategic error, P&G files an investigational new-drug application. The application put olestra in regulatory limbo amid a debate on whether olestra was a drug or a food.
1985: Research shows olestra does not reduce serum cholesterol levels by at least 15 percent, the minimum requirement for approval as a drug.
April 1987: P&G applies to the FDA for approval to use sucrose polyester as a fat substitute in snack foods and cooking oils that would be sold to consumers and food-service firms. Analysts estimate olestra could produce more than $1 billion a year in sales for P&G and change consumers' eating habits.
September 1987: P&G establishes a separate division to manage the olestra business.
December 1987: The Center for Science in the Public Interest calls for more research into olestra, saying P&G's research showed some rats used in its studies developed leukemia, pituitary tumors and liver abnormalities. The FDA later asks for new tests to be performed on mice.
February 1990: P&G chief Edwin Artzt says olestra's approval is taking longer than the company expected. The FDA ''continues to think of new questions to ask and data they want to see because it's apparent this is one of the biggest food-additive petitions they've ever faced.''
December 1993: President Clinton signs a bill allowing two one-year extensions on the olestra patent.
January 1994: P&G says it expects an FDA decision on olestra during the year.
October 1995: P&G chief John Pepper resurrects hope for olestra, predicting the company's Pringles potato chips and other products containing olestra could be on store shelves in 1996 if FDA approval comes soon.
November 1995: An FDA advisory panel deems olestra safe and recommends its approval in a 16-5 vote. FDA Commissioner David Kessler says he will make a decision within two months.
January 1996: FDA approves the use of olestra in certain snack foods and requires labeling on products containing the fat substitute. Frito-Lay is the first non-P&G company to say it will test snacks made with Olean, P&G's brand name for olestra.
March 1996: P&G commits to building its national olestra production plant in its Ivorydale complex in Cincinnati, and pledges to begin operations within three years.
May 1996: Frito-Lay begins selling potato and corn chips made with olestra in three small test markets: Eau Claire, Wis.; Cedar Rapids, Iowa; and Grand Junction, Colo.
June 1996: Frito-Lay becomes an equity partner in the olestra plant and, in return, is assured of receiving a national supply of olestra beginning in 1998. Other snack food companies have to wait until mid-1999.
September 1996: P&G rolls out fat-free Pringles potato chips made with olestra in Columbus.
February 1997: Frito-Lay begins a new, larger test market in Indianapolis.
March 1997: P&G extends its test of fat-free Pringles into portions of Indiana.
April 1997: Nabisco begins test-marketing the first crackers made with olestra - Fat Free Ritz crackers and Fat Free Wheat Thins - in stores in Marion, Ind., and Grand Junction, Colo.
Feb. 10, 1998: P&G and Frito-Lay announce plans for the national rollout of salted snacks containing olestra.
MAIN STORY
Infographic: The making of olestra
Mission: Get people to try one
Plant built on time
