Chemical Grade Definitions from Highest to Lowest Purity.
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 U.S.
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 National
Formulary (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.
Dietary supplements must meet USP standards IF they include the letters “USP” on the label. Many dietary supplement companies choose not to include “USP” on their label because it may increase their risk of regulatory action from the FDA even when they do follow USP standards. This makes it difficult for pharmacists, healthcare practitioners or consumers to know if a dietary supplement product is made to conform to USP’s quality standards.
USP standards for the following quality indicators are based on laboratory testing.
- Identity–is the product what it claims to be
- Potency–is it present in the right amount
- Purity–is it free from impurities, contaminants or other unwanted ingredients
- Performance–will it dissolve and disintegrate in the body so the active ingredient can be absorbed
Professional doctors became more prevalent after 1765, when the country’s first medical school was established in Philadelphia. At that time doctors diagnosed disease as well as compounded and dispensed medicine. However, even though the doctors were trained in how to properly prepare medicine, there was no assurance that the medicines they made were composed of quality materials or even if they were potent.
Prominent national and medical figures such as Benjamin Franklin and John Morgan, founder of the medical college, spoke about the need for a formulary of accepted medical treatments and a national pharmacopeia to set “some Standard amongst ourselves.” Part of their goal would be realized in 1820, with the publication of the first United States Pharmacopeia.
The U.S. Pharmacopeia is a reference of uniform preparations for the most commonly used drugs—with tests to ensure their quality, potency and purity.
As the practice of pharmacy grew, medicines were increasingly made not only by pharmacists but by commercial providers. Companies like Eli Lily began to include “U.S.P.” on their product labels to indicate to pharmacists, medical practitioners and patients that the product was made in accordance with the quality standards of the United States Pharmacopeia.
These three letters convey a great deal of information to the healthcare practitioner. They let the pharmacist or doctor know that the medicine or product in the bottle meets several key quality attributes that are necessary to ensure the medicine will perform as expected. USP standards for the following quality indicators are based on laboratory testing.
