Application guide / Version 1.0
The cleaning spec does not ask for a percentage
What a governing cleanliness document actually specifies for isopropanol, and what changes between 70 and 99.9.
Read what the process specification asks for
NASA JSC PRC-5001 Revision G, §5.12, states that “Isopropanol (IPA) must meet the requirements of TT-I-735A filtered to 10 microns or better prior to use.” It names a specification and a filtration state. It does not name a percentage. In the same paragraph, aqueous fluids “must utilize reagent grade water” meeting ASTM D1193 Type II except that silica content is not required, and where water is the verification fluid it must meet Grade A of JSC-SPEC-C-20D. Test fluids “shall be selected by the user and approved by the NASA procuring activity.”
That is the shape of a real cleanliness requirement, and a purchase request modelled on it looks nothing like “99.9% IPA.” It names the governing document and its revision, the specification the material must meet, the filtration or particulate condition required before use, and the authority that approves the fluid. A percentage on its own answers none of those. Confirm the current status and revision of any Federal Specification cited to you before writing it into an order; the designation on a decades-old drawing may no longer be active.
What the concentration figure actually changes
The difference between a 70 and a 99.9 figure is water, and water is a specification parameter with consequences you can reason about. It changes what is left behind when the solvent evaporates: nonvolatile residue is measured on the residue, and any dissolved or suspended matter carried in the diluent contributes to it. It changes evaporation behaviour and therefore drying and rinsing. It changes the handling classification of the delivered liquid: published closed-cup flash points aggregated for isopropanol give 12 °C (53 °F) for the substance and 75 °F open cup for a 91 percent solution, and 29 CFR 1910.106(a)(14)(iii) requires a mixture of compounds with different volatilities to be flash-tested in the form it is shipped.
It also changes what distillation can deliver. Isopropanol forms an azeotrope with water at 87.7 percent by weight, boiling at 80.37 °C at 760 mm Hg, so concentrations above that point are not reached by simple distillation and the higher figure implies a different production route and a tighter water specification. A container opened repeatedly in a humid room drifts back toward that composition, which is why the water content on the certificate and the water content at the bench are different numbers.
What the concentration figure does not do is make an antimicrobial claim. Efficacy statements for a specific concentration belong to registered products and their approved labelling, and this library makes none. Where a program requires an antimicrobial outcome, that requirement is answered from the governing document and the registered product’s label, not from a purity figure.
Separate the fluid record from the hardware record
PRC-5001 keeps cleanliness levels explicit and separable: Level 200 refers to size and count limits on particulate matter only, Level A refers to nonvolatile residue limits only — 1 mg per 0.1 m² — and Level 200A covers both. Verification is method-bound too: NVR determined in accordance with ASTM D2109-01, particulate determination in accordance with SAE-AS598, hydrocarbon content by total organic carbon per ASTM G144-01 where high-purity water is the final rinse. For HFE-7100 as a verification fluid, NVR “shall not be greater than 10 milligrams per one liter (mg/L)” determined by SSP 30573.
Our proposed record keeps three columns apart: what the delivered chemical is documented to be, what the cleaning process is approved to do, and what the component was verified to meet. The percentage on a drum sits only in the first column. Alliance sends a Certificate of Analysis when a customer asks, at no charge; name the analytes, methods and reporting limits you expect in the purchase order, and note which of your specification limits the certificate does not address at all.
- Which document and revision governs, and what does it name — a specification or a percentage?
- Is the requirement stated as assay, or as a maximum water content, and on which basis?
- What filtration or particulate condition must the fluid meet before use?
- Which cleanliness level applies to the hardware, and who approves the fluid for it?
Requirement → evidence → decision boundary
An editorial checklist for your review—not a table of product specifications.
| Requirement | Evidence to request | What it does not establish |
|---|---|---|
| Governing requirement | Document identifier, current revision, and the specification it names for the fluid | A percentage is not a specification, and a specification is not an approval to use. |
| Delivered material | Assay and water content with basis and method, plus filtration state | Assay does not establish nonvolatile residue or particulate cleanliness. |
| Hardware verification | Cleanliness level, verification method and the program’s acceptance record | A chemical certificate is not a hardware cleanliness record. |
Make the open questions useful
Record requirements, evidence gaps and approval owners in a downloadable purchasing brief.
Open the requirements worksheet →Revision record
1.0 · September 12, 2026 — Source-based editorial edition. No original testing or product qualification is claimed.
For commercial aerospace materials and purchasing reviews. No flight qualification, oxygen-service approval, propellant formulation or cleaning procedure is provided.
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