Malcolm W. (Mac) Jensen, 65, a retired director of the Bureau of Product Safety in the old Department of Health, Education and Welfare and a former official of the National Bureau of Standards, died Jan. 20 at the Wake County Medical Center in Raleigh, N.C., after heart surgery.

Mr. Jensen, who was born in Edgertown, Wis., was educated at the University of Wisconsin. He moved to the Washington area in 1950 and joined the National Bureau of Standards, where he became chief of the Office of Weights and Measures, manager of Engineering Standards and acting director of the Institute of Applied Technology.

In 1971, he became director of the Bureau of Domestic Commerce in the Commerce Department. He was director of the Bureau of Product Safety in HEW when he retired from the government in 1973.

Subsequently, Mr. Jensen was president of the Can Manufacturers Institute in Washington. He moved from Potomac to Raleigh in 1976 and was a product safety consultant at the time of his death.

Mr. Jensen was a former director of the American Society for Testing and Materials and the American National Standards Institute and a member of numerous other professional organizations.

Survivors include his wife, Gladys Couper Jensen of Raleigh; three sons, Malcolm Wayne Jr., of Gaithersburg, Donald Frederick, of Endicott, N.Y., and Robert Couper, of Raleigh; his mother, Gertrude Tallard Jensen of Raleigh, and eight grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the American Heart Association, or to a charity of one's choice.