EU AI Act Art. 4a: lawful basis for special-category data in bias detection

Lawful basis to process special-category data for bias detection in high-risk systems, with pseudonymisation and deletion once bias is corrected

By Jorge García Aibar Reviewed 2026-09-24

From clause to evidence Build the artefact, then file every output it produces as a record that names AIGE-OBL-EUAIA-ART4A. Drawn from chapter 08.

Text alternative

Clause: EU AI Act, Art. 4a.
Duty holder: Provider.
Applies from: 2026-07-27, In force.
Artefact: Data governance controls.
Layer: Layer 02 Inventory & Transparency.
Evidence record: Dataset card.
Record schemas: Dataset card .
The same topic in 20 other frameworks; the crosswalk section below links each clause.

When this obligation applies The first date in the row's status, then each later step: filled once its date has passed, outlined while it is still ahead of the review date.

Data table: the dates

Dates of AIGE-OBL-EUAIA-ART4A
Date	Step	Detail
2026-07-27	In force	new, in force

Id: AIGE-OBL-EUAIA-ART4A
Instrument: EU AI Act (post-Omnibus) law
Compared side by side: ISO 42001 vs EU AI Act · NIST AI RMF vs EU AI Act
Clause: Art. 4a
Duty holder: Provider
Authority: National MSA / DPAs
Applies from: 2026-07-27 In force · new, in force
System class: High-risk (Annex III) · High-risk (Annex I)

The artefact that evidences it

Data governance controls; pseudonymisation and retention-as-code; data card noting basis and deletion.

L2 Inventory & Transparency

What this obligation connects to Solid edges are direct relations, dashed ones looser (a case that cites the same article, a framework whose clauses only touch the topic); patterns and controls take the colour of their stack layer. Select a node to open it; the lists below give every relation in full.

Data table: every relation

Relations of AIGE-OBL-EUAIA-ART4A
Family	Item	Relation
Patterns	Dataset Admission Gate	Direct
Patterns	Drift & Fairness Monitor	Direct
Patterns	Fairness Eval Suite	Direct
Open controls	AIGE-CTL-DEPLOY-009 Fairness monitored by group in production	Direct
Open controls	AIGE-CTL-DATA-007 Special-Category Data Conditions	Direct
Same crosswalk topic	AI Verify 8.1.1, 8.2.1, 7.1.1, 7.2.1, 7.8.1, 8.3.1, 8.3.2, 1.4.1	Core clause
Same crosswalk topic	CSA AICM DSP-20, DSP-21, GRC-11, DSP-08, DSP-22	Core clause
Same crosswalk topic	China Deep Synthesis DeepSyn Art. 14	Core clause
Same crosswalk topic	China GenAI Measures GenAI Art. 7, GenAI Art. 8, GenAI Art. 11, GenAI Art. 4(2), GenAI Art. 7(3)	Core clause
Same crosswalk topic	CoE Convention CoE Art. 10, CoE Art. 11	Core clause
Same crosswalk topic	EU AI Act Art. 10, Art. 10(2)(f)–(g), Art. 53, Art. 53(1)(c), Art. 5(1)(e), Art. 59	Core clause
Same crosswalk topic	GAO AI Accountability 2.1, 2.2, 2.4, 2.5, 2.7, 3.8, 2.8	Core clause
Same crosswalk topic	GB/T 45654 GB/T 45654 Corpus security	Core clause
Same crosswalk topic	GDPR Art. 5(1)(c), Art. 25, Art. 9, Art. 5(1)(a), Art. 5, Art. 6, Art. 35	Core clause
Same crosswalk topic	ISO 42001 A.7, A.7.3, A.4, A.5.4	Core clause
Same crosswalk topic	NIST AI RMF MAP 2, MEASURE 2.10, MEASURE 2.11, GOVERN 3.1	Core clause
Same crosswalk topic	OWASP LLM LLM05:2026, LLM02:2026	Core clause
Same crosswalk topic	Singapore GenAI GenAI 2	Core clause
Same crosswalk topic	TC260 Framework 3.0 TC260 2.1.3, TC260 5.1	Core clause
Same crosswalk topic	UK ATRS ATRS 2.4.3, ATRS 2.4.2	Core clause
Same crosswalk topic	China Algo. Rec. AlgoRec Art. 21	Related clause
Same crosswalk topic	G7 Code G7 Action 11	Related clause
Same crosswalk topic	GPAI Code Copyright 1.1–1.5	Related clause
Same crosswalk topic	OECD AI Principles OECD 1.2	Related clause
Same crosswalk topic	UK DUAA UK GDPR Art. 22B	Related clause

Patterns that build it

Dataset Admission Gate (layer 1 and 2)
Fairness Eval Suite (layer 3)
Drift & Fairness Monitor (layer 4 and 5)

The same topic in other frameworks

From the topic crosswalk: the clauses filed under the same topics as this one. Mappings are illustrative, not a claim of conformity.

Open controls that evidence it

Draft controls in the open control profiles that map to this row: each states a requirement and the evidence it must leave behind.

AIGE-CTL-DATA-007 Special-Category Data Conditions (Data admission and privacy profile)
AIGE-CTL-DEPLOY-009 Fairness monitored by group in production (Deployment and monitoring profile)

Source

Chapter 08, section EU AI Act, post-Omnibus, checked against its sources on the review date above.

Machine-readable

This obligation: /api/v1/obligations/aige-obl-euaia-art4a.json
The register: /api/v1/obligations.json · CSV
Schema and stability promise: open data and API

Cite this obligation

García Aibar, J. (2026). EU AI Act Art. 4a: lawful basis for special-category data in bias detection (AIGE-OBL-EUAIA-ART4A). In AI Governance Engineering: The Thesis & Body of Knowledge (v0.5.0). https://doi.org/10.5281/zenodo.22956197. https://aigovernanceengineer.com/obligations/aige-obl-euaia-art4a. CC BY 4.0

BibTeX

@misc{aige2026obligation,
  author       = {Jorge García Aibar},
  title        = {{EU AI Act Art. 4a: lawful basis for special-category data in bias detection (AIGE-OBL-EUAIA-ART4A)}},
  howpublished = {In AI Governance Engineering: The Thesis \& Body of Knowledge},
  year         = {2026},
  version      = {0.5.0},
  doi          = {10.5281/zenodo.22956197},
  url          = {https://aigovernanceengineer.com/obligations/aige-obl-euaia-art4a},
  note         = {Version 0.5.0}
}

The artefact that evidences it

Patterns that build it

The same topic in other frameworks

Data governance

Fairness and non-discrimination

Privacy and data protection

Open controls that evidence it

Source

Machine-readable