Chemical purity grades (technical, food, pharma, analytical)
The same chemical is sold in different purity and impurity limits at different prices. Technical or industrial grade is for general manufacturing; food grade (E-number additives, FCC or JECFA specifications, heavy-metal limits) for food and feed; pharmacopoeia grade (USP, EP/Ph. Eur., BP, JP) for medicines and some cosmetics, produced under GMP; analytical or reagent grade (ACS, AR, HPLC) for laboratories. Using a lower grade in place of a higher one breaches regulations, so the grade and reference specification must be written on the order and the COA.
Related terms
CAS number (chemical identifier)
A unique numeric identifier such as “7732-18-5” (water) assigned to each chemical substance by the Chemical Abstracts Service of the American Chemical Society. Because the same substance can be sold under many trade and local names, it is the most reliable way to avoid confusion in sourcing; SDSs, REACH registrations, customs and restricted-substance lists all work by CAS number. Mixtures have no single CAS number – their components are listed separately. In the EU the EC (EINECS) number is also used.
Certificate of analysis (COA)
A document in which the producer or an independent laboratory reports the test results for a specific lot together with the specification limits. It shows the product name, lot number, production date, test method (e.g. ASTM, ISO), measured value and acceptance range. A TDS gives a product’s typical properties; a COA gives the actual values of the lot delivered. Under a letter of credit the COA must be issued by the party and with the content the credit requires.
Food-contact compliance (EU 10/2011, FDA)
Evidence that plastics used for food packaging and equipment do not transfer substances into food above permitted limits. In the EU the framework Regulation 1935/2004 and, for plastics, Regulation 10/2011 apply – a positive list of substances plus overall and specific migration limits; in the USA, FDA 21 CFR Part 177. Buyers should request the supplier’s declaration of compliance (DoC) covering additives and, where needed, migration test reports; recycled plastics are also subject to Regulation (EU) 2022/1616.