Why MEG Quality Is Not Always “Standard”

On paper, MEG appears uniform: high purity, low moisture, and minimal impurities. In practice, however, cargo quality depends heavily on:

• Feedstock origin

• Production technology

• Storage conditions

• Transport method

Different producers operate under varying purification standards. While contract specifications may look identical, the actual delivered quality can differ meaningfully.

Even small deviations in aldehydes or glycol impurities can affect polyester polymerization efficiency.

2. Water Content: The Most Common Silent Problem

Excess moisture is the single most frequent quality issue in MEG shipments.

Water enters MEG cargoes through:

• Improper tank cleaning

• Condensation during loading

• Leaking valves or pipelines

• Poor nitrogen blanketing

For textile-grade applications, moisture levels above acceptable thresholds can reduce intrinsic viscosity and compromise fiber strength.

Spot cargoes are particularly vulnerable, as they often change tanks multiple times before reaching the end user.

 Table 1 — Common MEG Quality Deviations and Their Impact

3. The Rising Risk of Off-Spec Cargoes

Off-spec MEG shipments are increasing as market volatility pushes traders to move marginal material.

These cargoes may technically meet minimum specs but fail to perform in downstream processes.

Buyers often discover problems only after unloading — when laboratory results reveal deviations from agreed parameters.

At that point, renegotiation becomes difficult, especially in spot transactions without strong quality clauses.

4. Why Spot Buyers Face Higher Exposure

Contract buyers typically benefit from:

• Pre-shipment inspections

• Certificate of analysis verification

• Defined rejection rights

Spot buyers, on the other hand, often accept material “as is,” increasing exposure to hidden defects.

This makes spot MEG trading significantly riskier during tight supply cycles.

 Table 2 — Risk Comparison: Spot vs Contract MEG Purchases

5. How Professional Buyers Mitigate MEG Quality Risks

Experienced importers apply several safeguards:

• Independent surveyors at loading ports

• Strict moisture and impurity limits

• Retention samples for dispute resolution

• Performance-based supplier evaluation

• Preference for producers over traders

These practices dramatically reduce exposure to off-spec material.