Aerospace materials & cleanliness handbook

Two objects, two evidence records

NASA JSC’s PRC-5001 Revision G describes hardware cleanliness in terms that can include particulate and nonvolatile residue criteria, with precision-cleaning verification beyond visual inspection. Its requirements have a defined program and process context; they are not a universal solvent specification.

The purchasing distinction is important: a chemical lot record describes the supplied material, while a hardware acceptance record addresses a component after the relevant process. Neither record should silently stand in for the other.

Ask for the method and the acceptance authority

Our proposed review captures the required property, method, units, limit and governing document revision in separate fields. If a request says only “low residue,” ask which object is being evaluated, how it is evaluated and who sets the limit.

A product’s advertised grade does not by itself demonstrate that a specific component meets a program cleanliness requirement. Request the exact chemical documents, then keep the component verification and process approval with the responsible engineering and quality team.

• Does the requirement apply to the liquid product, an extract or the hardware?
• Are particulate and residue requirements separately identified?
• Is the document revision the one required by the purchase order?
• What evidence must exist before the component can be released?

Requirement → evidence → decision boundary

An editorial checklist for your review—not a table of product specifications.

Cleanliness is part of a hazards assessment

NASA White Sands describes assessing oxygen-system cleanliness requirements and the risks associated with contamination. Its oxygen-service cleaning capability is not a generic cleaning recipe and does not establish that an off-the-shelf chemical is approved for every oxygen application.

Do not let a purity claim become a compatibility claim

White Sands also describes material and component compatibility assessment capabilities. For procurement, keep material identity, cleanliness evidence and compatibility approval as distinct records. Ask the responsible authority what evidence is required for the actual system.

Stop the substitution at the approval boundary

Our suggested purchase-order language identifies the approved material and document revision, the required lot evidence and the person authorized to accept a deviation. If those requirements are absent, mark the decision unresolved; a supplier’s general grade label cannot fill that gap.

This guide does not prescribe solvents, operating conditions, cleaning sequences or acceptance limits for oxygen hardware. Those decisions require qualified personnel and the governing process. Do not use a worksheet or a quote as permission to clean, test or operate an oxygen system.

• What exact system and requirement does the approval cover?
• Which organization owns compatibility and cleanliness acceptance?
• Does a proposed substitution require a new assessment?
• Which receiving discrepancy requires a hold instead of release?

Requirement → evidence → decision boundary

An editorial checklist for your review—not a table of product specifications.

A mission-specific case—not a universal limit

The 2017 OSIRIS-REx contamination-control paper’s abstract describes a mission-specific strategy, including witness materials used during assembly, testing and flight. It illustrates an evidence trail designed around the scientific purpose of that mission.

Only the abstract is reviewed here. We do not transfer its mission criteria into a general aerospace purchasing specification or present this older case as new research.

Treat preservation as a requirement

NASA JSC PRC-5001 addresses preventing recontamination during handling and interim packaging. That provides a useful foundation for asking what must remain protected between verification and use. Check the program’s actual requirements and current controlled documents.

Build a receiving evidence chain

Our proposed purchasing record connects the material lot, required verification, packaging configuration, receiving condition and release decision. Capture discrepancies without assuming that intact outer packaging proves every internal cleanliness requirement.

Specify who can assess a damaged seal, missing report or undocumented handling event. Keep the chemical supplier’s delivery evidence distinct from the program’s final hardware release record. The practical outcome is a clear handoff, not an unsupported promise of contamination-free performance.

• What must packaging preserve, and how is that requirement documented?
• Which evidence accompanies each lot or component?
• Who owns the decision after a preservation discrepancy?

Requirement → evidence → decision boundary

An editorial checklist for your review—not a table of product specifications.