If you’re new to buying sugar internationally, the ICUMSA number on a spec sheet can look like a purity rating. It isn’t, exactly — and understanding what it actually measures will save you from ordering the wrong grade.
What the ICUMSA Scale Actually Measures
ICUMSA (International Commission for Uniform Methods of Sugar Analysis) is a color scale, not a purity scale. It measures how much light passes through a sugar solution, expressed in ICUMSA units (IU) — the lower the number, the whiter and more refined the sugar looks. A sugar with an ICUMSA rating of 45 is highly refined and nearly colorless; a rating in the hundreds to low thousands describes raw or less-refined sugar with a visible amber or brown tint. Purity and color are strongly correlated in practice, which is why the scale works as a practical shorthand, but the number itself is measuring color.
Common Grades and Their Uses
ICUMSA 45 sugar is the standard for retail-ready white sugar, soft drinks, and any application where color and clarity matter. Higher ICUMSA numbers (less refined, more color) show up in brown sugar and muscovado sugar, both valued precisely because they keep more of the molasses content that refining removes — the “less refined” trait is the selling point, not a defect. See the full sugar range for specifications on each grade.
How to Specify Sugar Grade in Your Purchase Order
Don’t just write “white sugar” on a purchase order — specify the ICUMSA rating you need (45, 100, 150, etc.), since two suppliers’ idea of “white sugar” can differ by a meaningful margin in color and price. If your end use is sensitive to color (bottled beverages, confectionery), ask for a certificate of analysis with the actual tested ICUMSA reading on your specific lot, not just the grade’s nominal spec.
Packaging and Storage Considerations
Sugar is hygroscopic — it absorbs moisture from the air, which affects flow and shelf life if storage and packaging aren’t handled correctly. Confirm your supplier uses moisture-appropriate packaging (typically multi-wall or laminated bags) for your climate and transit time, particularly for longer sea voyages to humid destinations.
Ready to specify a grade and volume? Request a quote and we’ll confirm ICUMSA rating, packaging, and lead time before you commit.