American Optical Corporation
Allied Minerals
AMCOL International
Brillion Iron Works
C-E Minerals
Chicago Fire Brick Company
Clemco Industries
Dalloz Safety
Eastern Safety Equipment
ED Bullard Company
Elvin Corporation
Encon Manufacturing Company
Flexo Products
Foseco
Foseco Metallurgical
Glendale Protective Technologies
Inco Safety Products
Industrial Holding
Kelco Sales & Engineering
Kyanite Mining
Lafarge Building Materials
Lafarge Midwest
Lockheed Martin
Louis N. Gerson, Inc.
MA Bell
Mine Safety Appliances
3M Company
National Refractories and Minerals
North Safety Products
Norton Company
Ottawa Silica Company
The Pangborn Corporation
Parmelee Industries
PK Lindsay Company
Porter Warner Industries
Pulmosan Safety Equipment
Sammons-BW, Inc.
Scott Aviation Company
Textron, Inc.
Truman’s, Inc.
Unimin Corporation
U.S. Filter Operating Services
U.S. Silica Company
The Vallen Corporation
Wheelabrator Frye
