Two chemical labels need a clear explanation
Hong Ha’s hydrated lime catalog lists Ca(OH)2 above 90% and CaO above 70%, alongside impurity limits and a 200 mesh format. The entry does not identify a total or available assay basis. Treat those numbers as published references and request clarification before comparing them with your own specification.
The National Lime Association describes hydrated lime as the hydroxide product made from quicklime and water. A result labelled CaO and a result labelled Ca(OH)2 describe different reporting expressions; do not add the two percentages or assume they are interchangeable purity claims.
Make the COA comparable with your specification
Ask the supplier and your laboratory to identify the measured parameter, analytical method and reporting basis. If your acceptance limit refers to available content, a result with an unspecified basis is not enough to show compliance. Record the agreed basis in the purchase specification as well as the analysis review.
A certificate of analysis should also identify its sample or batch and report date. A historical report can show what was tested at that time; it does not replace analysis relevant to the material now offered.
Review physical and application requirements separately
A 200 mesh description still needs the sieve standard and required passing fraction. Add the impurity limits and any end-use approval evidence your process requires. An industrial catalog entry alone does not establish potable-water, food or another regulated-use approval.
For handling arrangements, request the current safety data sheet and have the receiving team review packing and storage requirements. A COA and an SDS answer different purchasing questions.
A short document review checklist
- Do the product name and offered grade match the enquiry?
- Are CaO and Ca(OH)2 results clearly labelled with methods and assay basis?
- Are required impurities and fineness reported or covered by an agreed test?
- Is the sample or batch identifiable, and is the report relevant to the offer?
- Has the buyer’s technical team approved the intended application?
Review hydrated lime catalog references ↗ · Understand quality evidence ↗