CAS Registry Number: Chemical Abstracts Service Registry Number is a unique identifier for a chemical and its synonyms. CAS numbers identify the chemical, but not its concentration or specific mixture. CAS Registry Numbers are assigned by the Chemical Abstracts Service, a division of the American Chemical Society.
A package is a small container in which a quantity of something is sold. Packages are either small boxes made of thin cardboard, or bags or envelopes made of paper or plastic. ...a package of doughnuts. It is listed among the ingredients on the package.
noun push the envelope a flat paper container, as for a letter or thin package, usually having a gummed flap or other means of closure. 1; noun push the envelope something that envelops; a wrapper, integument, or surrounding cover. 1; noun push the envelope Biology. a surrounding or enclosing structure, as a corolla or an outer membrane. 1 noun push the envelope Geometry. a curve or surface tangent to each member of a set of curves or surfaces.