# ISO 4021:1977 — Withdrawn and superseded ISO standards

For ISO 4021:1977, item title is Hydraulic fluid power — Particulate contamination analysis — Extraction of fluid samples from lines of an operating system; status code is 9599; successor is ISO 4021:1992; withdrawn / published date is 1977-12-01, recorded from its source on 2026-08-05.

- **Identifier:** ISO 4021:1977 _(verified: appears in the quote below)_
- **Item title:** Hydraulic fluid power — Particulate contamination analysis — Extraction of fluid samples from lines of an operating system _(verified: appears in the quote below)_
- **Status code:** 9599 _(verified: appears in the quote below)_
- **Successor:** ISO 4021:1992
- **Withdrawn / published date:** 1977-12-01 _(verified: appears in the quote below)_

## What the source says

> 9705,IS,,ISO 4021:1977,Hydraulic fluid power — Particulate contamination analysis — Extraction of fluid samples from lines of an operating system,Transmissions hydrauliques — Analyse de la pollution par particules — Prélèvement des échantillons de fluide dans les circuits en fonctionnement,1977-12-01,1,['23.100.60'],ISO/TC 131/SC 8,9599,,[9706],"['en','fr']",2,

## Source

- https://isopublicstorageprod.blob.core.windows.net/opendata/_latest/iso_deliverables_metadata/csv/iso_deliverables_metadata.csv

Last verified: 2026-08-05. Review by: 2027-02-01.
Part of [Withdrawn and superseded ISO standards](https://referencesource.org/iso-standard-supersessions/).