Extra Pure Grade chemicals

What the grade means

Extra pure is a manufacturer-defined grade, common in Indian and European catalogues, that sits between laboratory reagent and analytical reagent. It typically offers an assay of 98.5 to 99.5 percent or higher and more impurity parameters than LR, often with limits close to AR for the commonest contaminants.

Some catalogues abbreviate extra pure as EP, which is easily confused with the European Pharmacopoeia. Zemixal writes Ph. Eur. for pharmacopoeial material, and every COA states the specification basis so there is no doubt.

Typical specification points

Assay of 98.5 percent or more, insoluble matter at or below 0.01 percent, chloride and sulfate in the hundredths or thousandths of a percent, heavy metals at or below 10 ppm and iron at 5 to 10 ppm.

When to choose it

Extra pure is a good fit for synthesis that needs cleaner inputs than LR, routine QC tests that do not depend on trace impurities, and pilot work where AR prices would add up quickly.

Documentation

Each lot comes with a COA and GHS SDS. Compare LR and AR before deciding.