ICUMSA 45 vs ICUMSA 150: What the Number Really Means

Sugar contracts are quoted by an ICUMSA number as if it were a product name. It is not. ICUMSA stands for the International Commission for Uniform Methods of Sugar Analysis, and the number is the colour of a sugar solution measured in ICUMSA units (IU) under one of the Commission's standardised methods. Lower means whiter. Knowing what the number does and does not tell you prevents the most common specification disputes in refined-sugar trade.

How the colour is measured

A sample is dissolved, filtered and the absorbance of the solution is read at 420 nm, normally at pH 7.0, using the ICUMSA GS2/3 methods for white sugar (the GS2/3-9 and GS2/3-10 solution-colour procedures). Polarisation, the second figure on every certificate, is determined by polarimetry under ICUMSA GS2/3-1 and is expressed in degrees Z. Both figures depend on correct sampling: a sample drawn from the top of one bag in a warehouse says little about a 12,500 MT cargo.

Rule: ICUMSA is a colour result on a specific sample. It is not a quality grade, not a certification and not a guarantee of any other parameter.

ICUMSA 45: refined white sugar

ICUMSA 45 is the commercial name for fully refined white sugar with a maximum solution colour of 45 IU. Typical contract specifications used in international trade include:

• Polarisation: minimum 99.80 °Z
• Moisture: maximum 0.04 % m/m
• Ash (conductometric): maximum 0.04 % m/m
• Colour: maximum 45 IU
• Reducing sugars: maximum 0.04 % m/m
• Sulphur dioxide: maximum 20 mg/kg (lower in EU food contracts)
• Granulation: fine to medium crystal, free flowing, no lumps
• Radiation, heavy metals and microbiology within the limits of the destination food law

Refined sugar of this quality broadly corresponds to the EU standard quality for white sugar (Category 2 of the EU sugar classification). It is the grade for beverage producers, pharmaceutical use and retail packing, and it is the grade on which most fraudulent offers are built because the name is well known.

ICUMSA 150: white crystal sugar

ICUMSA 150 describes a white crystal sugar, often called plantation white or mill white, that has been clarified at the mill rather than fully refined. The typical specification is:

• Polarisation: minimum 99.70 °Z
• Moisture: maximum 0.06 to 0.10 % m/m
• Ash: maximum 0.10 % m/m
• Colour: maximum 150 IU
• Sulphur dioxide: maximum 70 mg/kg (sulphitation process)

The sugar is slightly off-white, has higher ash and a wider grain distribution and is perfectly suitable for industrial baking, confectionery and many domestic markets. Brazilian crystal sugar sold at ICUMSA 100 to 150 is the largest single stream of this grade. Below it sits VHP raw sugar at 600 to 1,200 IU, which is a refinery feedstock, not a food product.

Side by side

Why the other parameters decide the deal

Buyers who fixate on the colour value lose on the parameters that cause rejections. Moisture above 0.06 % in bagged sugar leads to caking during a 30-day voyage. High ash in a beverage plant shows up as haze and off-taste. Sulphur dioxide above the destination limit makes an otherwise perfect cargo unsaleable in the EU. Grain size affects dissolution rates and dust in automated lines. A professional specification therefore lists all of these with test methods, and the certificate of analysis at loading must report every one of them.

Packing, sampling and documents

Refined sugar is shipped in 50 kg polypropylene bags with polyethylene liner, in 1,000 kg big bags, or in bulk in container liners. Sampling follows the inspection company's plan (typically square root of the number of bags, minimum fixed number per lot), composite samples are sealed and split between buyer, seller and laboratory. The contractual document set is the certificate of analysis, certificate of weight, certificate of origin, phytosanitary certificate and, for most destinations, a radiation certificate. If the letter of credit does not call for these documents by name, the ICUMSA figure in the contract is unenforceable at the bank.

Reading an offer

1. Check that the colour and polarisation are stated with ICUMSA methods, not as "approximately".
2. Check that the origin matches the process: a mill cannot produce 45 IU without a refinery stage.
3. Match the price to the grade. ICUMSA 45 trades at a premium over the London No. 5 white sugar contract; ICUMSA 150 trades at a discount to it. An ICUMSA 45 offer priced below the futures benchmark is not an opportunity.
4. Require analysis at loading by an inspector you appoint and pay.

The number is where the conversation starts. The certificate on the loaded cargo is where it ends.