A Technical Data Sheet (TDS) backed by an independent NABL-accredited lab is the single best protection against inconsistent material. But the figures only help if you know what they mean. Here is a plain-English guide.
SiO₂ (silica content)
The headline number. High-grade RHA runs 85–92% SiO₂. It tells you how much reactive material you are actually buying. A low figure usually signals unburned carbon or mineral impurities.
Loss on Ignition (LOI)
LOI measures the mass lost when the sample is re-heated — largely unburned carbon. Lower is cleaner. High LOI can increase water demand in concrete and reduce performance.
Fineness / particle size
For pozzolanic use, fineness drives reactivity: finer particles have more surface area to react with free lime. For steel-grade products, particle size and flow determine how the material spreads and insulates.
Moisture
Affects handling, storage life and dosing accuracy. Excess moisture also means you are paying freight for water rather than product.
Why NABL accreditation matters
NABL is India’s national accreditation body for testing laboratories. A NABL-accredited report means the lab’s methods and competence have been independently audited — giving export buyers and procurement teams figures they can rely on, not in-house claims.
The bottom line
Ask for a current, NABL-backed TDS, and check SiO₂, LOI, fineness and moisture against your application’s needs. Just as important: ask how consistent those numbers are batch to batch.
Need RHA to a verified spec?
Get NABL-tested, high-silica RHA with documentation. Tell us your volume and target spec.
