Technical Grade and Pure Grade are chemical grade designations indicating purity tier. Technical grade is the industrial-use grade, typically 90-99% pure with trace impurities acceptable for most industrial processing applications. Pure grade, variously called reagent grade, ACS grade, or analytical grade, is 99.5%+ pure with controlled impurity profiles, used in laboratory analysis, electronics manufacturing, and pharmaceutical applications. Pharmaceutical (USP / EP / JP) and food grades (FCC) have specific impurity thresholds beyond simple purity numbers. The grade designation drives a 2-10x price differential between technical and pure grades for the same nominal substance, and determines which manufacturing applications the chemical is suitable for.
The chemical grade hierarchy
| Grade | Typical purity | Impurity profile | Common applications |
|---|---|---|---|
| Crude / Industrial / Technical | 90-99% | Trace impurities; not specified individually | Industrial processing, manufacturing inputs, water treatment, metal processing |
| Commercial | 95-99% | Specified within ranges | Specialty manufacturing, formulation |
| Reagent / ACS | 99.5%+ | Specified maximum levels for ~10-20 named impurities | Laboratory analysis, R&D, fine chemistry |
| USP (US Pharmacopoeia) | 99.5%+ | USP monograph-specified impurity limits | Pharmaceutical manufacturing in US |
| EP (European Pharmacopoeia) | 99.5%+ | EP monograph-specified | Pharmaceutical manufacturing in EU |
| JP (Japanese Pharmacopoeia) | 99.5%+ | JP monograph-specified | Pharmaceutical manufacturing in Japan |
| FCC (Food Chemicals Codex) | Specified per substance | FCC monograph; food-contact and food-additive | Food and beverage manufacturing |
| Electronic Grade / Semiconductor Grade | 99.999%+ | Sub-ppm metal impurities; sub-ppb for some | Semiconductor manufacturing |
| HPLC Grade | 99.9%+ | Tested for HPLC suitability | Analytical chemistry |
| Spectroscopy Grade | 99.9%+ | UV/IR transparency required | Analytical chemistry |
The grade hierarchy is roughly continuous, a “reagent grade” from one factory may be 99.6%, while another factory’s “USP grade” is 99.7%. The COA’s specific numerical specification matters more than the grade name.
Worked grade examples
For sodium hydroxide (CAS 1310-73-2):
| Grade | Typical purity | Application |
|---|---|---|
| Industrial 50% solution | NaOH content 49-51% by weight | Pulp and paper, textile, water treatment |
| Industrial 99% solid | NaOH 99%+ | Chemical synthesis, soap manufacture |
| Reagent grade pellets | NaOH 99.0%+, low Na2CO3 | Laboratory titration |
| USP grade | NaOH 99.5%+, USP monograph compliant | Pharmaceutical formulation |
For acetic acid (CAS 64-19-7):
| Grade | Typical purity | Application |
|---|---|---|
| Glacial acetic acid (industrial) | 99.5-99.8% | Acetate production, vinyl acetate monomer |
| Glacial acetic acid (commercial) | 99.85% | Food and pharmaceutical inputs |
| ACS reagent grade | 99.7%+, low water | Lab analysis |
| FCC food grade | Specified per FCC | Food acidulant |
| Electronic grade | 99.99%+ | Semiconductor cleaning |
Why grade selection matters
Three operational reasons:
- Price differential. A reagent-grade chemical typically costs 2-5x the technical grade for the same molecule; pharmaceutical grade can be 5-15x; electronic grade can be 10-50x. Specifying higher grade than the application requires wastes money.
- Manufacturing compatibility. A pharmaceutical formulator cannot use technical-grade input material without violating GMP requirements. A semiconductor manufacturer cannot use reagent-grade acetic acid because the metal impurities exceed device-fabrication tolerances. Grade has to match the application.
- Regulatory documentation. USP / EP / JP grades require specific batch-level testing per the relevant pharmacopoeia monograph. Without the monograph-compliant testing, the cargo is not pharmaceutical grade regardless of purity numbers.
How grade selection catches buyers off guard
Three failure patterns recur:
- Grade name mismatch between supplier and buyer. A Chinese factory’s “reagent grade” may not match a US lab’s “ACS reagent grade.” Always specify the grade by reference standard (USP, ACS, FCC) rather than by generic name.
- Spec-creep across batches. A factory may produce nominally the same grade with varying actual specs across batches. The buyer’s QC discovers a tighter spec needed and complains; the factory says “you ordered the standard grade.” Specify the actual numerical specification on the purchase order.
- Grade upgrade for higher prices. A buyer paying premium prices for “USP grade” should verify the COA actually shows USP monograph compliance. Some Chinese factories label as USP but ship technical grade with USP-compliant testing only on a sample batch.
Practical sourcing notes
For chemical buyers specifying grade:
- Reference the standard explicitly. “Acetic acid 99.7% reagent grade per ACS specification” is unambiguous; “high-purity acetic acid” is not.
- Specify the numerical specs that matter for your application, purity, water content, specific impurity limits, particle size, etc.
- Require monograph-compliant COA for pharmacopoeia grades.
- For new factory relationships, do a factory audit to verify the factory has the analytical capability to support the claimed grade.
- Cross-check via third-party inspection for first shipments of higher-grade products.
Grade and the CAS number
The CAS number identifies the substance, not the grade. The same CAS number applies to technical grade and to pharmaceutical grade of the same molecule. The grade is a separate specification layer above the substance identity.
For REACH and TSCA registration, the substance is registered by CAS number; the grade is specified in the marketing documentation but does not create a separate regulatory entity. A factory registered for technical-grade and pharmaceutical-grade of the same CAS number is registered for one substance, not two.
Related terms
COA is the per-batch quality certificate that confirms the grade. MSDS is largely grade-independent (the substance hazards are similar across grades). CAS Number identifies the substance regardless of grade. Factory Audit and Third-Party Inspection verify the factory’s grade-claim integrity. Batch Number tracks specific production runs.