1. A.C.S.

A chemical grade of highest purity and meets or exceeds purity standards set by American Chemical Society (ACS).

2. Reagent

High purity generally equal to A.C.S. grade and suitable for use in many laboratory and analytical applications.

3. U.S.P.

A chemical grade of sufficient purity to meet or exceed requirements of the United States Pharmacopeia (USP); acceptable for food, drug, or medicinal use; may be used for most laboratory purposes.

4. N.F.

A grade of sufficient purity to meet or exceed requirements of the United States National Formulary. (Since bought out and merged with the United States Pharmacopeia, USP-NF.)

5. Lab

A chemical grade of relatively high quality with exact levels of impurities unknown; usually pure enough for educational applications. Not pure enough to be offered for food, drug, or medicinal use of any kind.

6. Purified

Also called pure or practical grade, and indicates good quality chemicals meeting no official standard; can be used in most cases for educational applications. Not pure enough to be offered for food, drug, or medicinal use of any kind.

7. Technical

Good quality chemical grade used for commercial and industrial purposes. Not pure enough to be offered for food, drug, or medicinal use of any kind.