The European manufacturer of Pyrex, Arc International, uses borosilicate glass in its Pyrex glass kitchen products;[2] however, the U.S. manufacturer of Pyrex kitchenware uses tempered soda-lime glass.[3] Thus Pyrex can refer to either soda-lime glass or borosilicate glass when discussing kitchen glassware, while Pyrex, Bomex, Duran, TGI and Simax all refer to borosilicate glass when discussing
Otto Schott in the late 19th century[1] and sold under the brand name "Duran" in 1893. After Corning Glass Works introduced Pyrex in 1915, the name became a synonym for borosilicate glass in the English-speaking world.