- Atochem, Inc. purchased Racon, Inc., operator of a Wichita, KS refrigerants plant
- Atochem North America, Inc. was formed on December 31 as a result of the merger of Pennwalt Corporation, M&T Chemicals, and Atochem, Inc.
- A division of the Rohm and Haas Company began manufacturing Plexiglas® acrylic sheets in Matamoros,Mexico.
- Elf Atochem S.A. and Air Liquide S.A. began hydrogen peroxide operations in Bécancour, Québec, Canada as Oxychem Canada, Inc.
- Elf Aquitaine formed Atochem Inc., a maker of industrial and specialty chemicals.
- Pennwalt's Geneseo, NY plant expanded, doubling the capacity of retone peroxides used in the manufacture of polyester plastics.
- M&T Chemicals, Inc. opened its Mobile, AL plant to manufacture plastic additives
- Pennwalt announced plans for a new 10-million-pound continuous process peroxyester facility at Crosby,TX. The plant was completed in 1979
- New mercaptan plants at Beaumont, TX and at the Pennwalt Holland B.V. subsidiary were completed
- M&T Chemicals, Inc. was acquired by Elf Aquitaine
- A plant for production of methyl and ethyl mercaptans was completed at Beaumont, TX making Pennwalt the world's leading producer of these chemical intermediates.
- The industry's first continuous process for the manufacture of peroxydicarbonates started at Pennwalt's plant in Geneseo, NY.
- Pennwalt formed a thio and fine chemicals division in recognition of the growing sales specialization needed to penetrate vital growth markets.
- The Rohm and Haas Company began manufacturing Plexiglas® acrylic resins in Kensington, CT. (In October 1992, Rohm and Haas and Elf Atochem S.A. became partners in the AtoHaas joint venture for the manufacture of Plexiglas acrylics. In 1998, Elf Atochem became sole owner of the Plexiglas business).
- Pennwalt acquired Ozark-Mahoning, Tulsa, OK the largest producer of fluorspar in the U.S.and manufacturer of fluorine-bearing specialties.
- A major expansion of Pennwalt'sHouston mercaptan plant was completed.
- Rilsan Industrial, Inc., a subsidiary of Elf Aquitaine, opened a new plant in Birdsboro, PA for the production of Nylon II.
- Pennwalt opened a new plant for production of low-temperature polymerization initiators in Geneseo, NY.
- Pennwalt moved its corporate headquarters to a new building at Three Parkway in Philadelphia.