ACS stands for American Chemical Society. ACS is a professional commercial entity selling membership and technical documents. Among the documents offered by ACS are ACS quality documentation. ACS has defined specifications for different chemicals. Such specifications can be purchased and accessed in different formats. When a chemical product meets the specification defined by ACS, it is called ACS grade.
USP is a publisher of quality standards and test methods for chemicals used in pharmaceutical industries. UPS stands for United States Pharmacopoeia.
CHEMDIRECT is an online marketing website for chemicals.