Compressed air quality testing now reaches below 100 nm. For oil-injected screw compressors that shifts attention to separator condition, oil selection and filter change discipline.
The change
Industry reporting states that on 2 May 2026 the International Organization for Standardization published ISO 8573-7:2026 — Compressed Air Quality, Part 7: Determination of Nanoparticles — introducing measurement requirements for particles at and below the 100 nm range.
A separate revision of the TÜV Rheinland white paper on oil-free compressed air systems, reported on 16 May 2026, moved in the same direction by asking for full-chain ISO 8573-1 Class 0 verification from intake filtration through to the point of use.
Why oil-injected machines are affected too
Nanoparticle attention is usually associated with oil-free plants, but oil-injected screw compressors feed the same downstream network. Carry-over from a tired oil separator, a saturated coalescing filter or degraded lubricant is exactly the contamination class the new measurement method makes visible.
The practical consequence for a service provider is documentation: the customer needs to show what was fitted, when, and with which lubricant specification — not only that the compressor runs.
- Replace the oil separator on condition and interval, not only when carry-over is already visible.
- Match lubricant grade to the manufacturer's specification; mixed oils change separation behaviour.
- Record filter part numbers, oil batch and running hours in the service report.
What we do on site
On a mobile service visit we replace air, oil and separator elements, check the intake path for leaks that bypass filtration, sample the oil condition, and hand over a written report with the parts and hours logged. That report is what an auditor asks for when air-quality classes are part of a customer's own certification.
Summary — our conclusions
The article above is our own rewrite of the cited publications. Here is the short version.
- ISO 8573-7:2026 makes nanoparticle contamination measurable — including from oil-injected machines.
- Separator condition and filter discipline become auditable quality factors, not just maintenance items.
- A documented service report with parts and hours is now part of the customer's compliance evidence.
Sources and citations
Every statement above is traceable. Open the original publication to verify the figures and dates.
- [1] ISO 8573-7:2026 Adds Nanoparticle Limits for Oil Screw Compressors — Sector Vantage, 2026-05-08
- [2] TÜV Rheinland Releases New Oil-Free Systems Certification White Paper — Sector Vantage, 2026-05-18
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