---
title: "Misuse of substances — EASA Definition · Avioverse"
description: "Annex I — Definitions for terms used in Annexes II to IX, Regulation (EU) No 965/2012: ‘misuse of substances’ means the use of one or more psychoactive…"
url: "https://avioverse.aero/glossary/easa/misuse-of-substances"
---

# misuse of substances

EASA defines “misuse of substances” in 2 regulations, worded for each regulation's scope. The wording below is reproduced verbatim from the EASA Easy Access Rules, with a link to the paragraph it comes from.

> ‘misuse of substances’ means the use of one or more psychoactive substances by flight crew, cabin crew members and other safety-sensitive personnel in a way that:
>
> (a) constitutes a direct hazard to the user or endangers the lives, health or welfare of others, and/or
>
> (b) causes or worsens an occupational, social, mental or physical problem or disorder;

Annex I — Definitions for terms used in Annexes II to IX · Air Operations · Regulation (EU) No 965/2012 · Easy Access Rules, 27 Mar 2026 revision · [Read the article](https://avioverse.aero/regulations/easa/air-ops/definitions/powers-and-recitals#annex-i-definitions-for-terms-used-in-annexes-ii-to-ix)

> ‘misuse of substances’ means the use of one or more psychoactive substances by aircrew in a way that, alternatively or jointly:
>
> (a) constitutes a direct hazard to the user or endangers the lives, health or welfare of others;
>
> (b) causes or worsens an occupational, social, mental or physical problem or disorder;

MED.A.010 · Aircrew · Regulation (EU) No 1178/2011 · Easy Access Rules, 25 Nov 2025 revision · [Read MED.A.010](https://avioverse.aero/regulations/easa/aircrew/part-med/subpart-a#med-a-010)

## Defined in the same article

- [accelerate-stop distance available (ASDA)](https://avioverse.aero/glossary/easa/accelerate-stop-distance-available)
- [acceptable means of compliance (AMC)](https://avioverse.aero/glossary/easa/acceptable-means-of-compliance)
- [acceptance checklist](https://avioverse.aero/glossary/easa/acceptance-checklist)
- [accredited medical conclusion](https://avioverse.aero/glossary/easa/accredited-medical-conclusion)
- [adequate aerodrome](https://avioverse.aero/glossary/easa/adequate-aerodrome)
- [adequate vertiport](https://avioverse.aero/glossary/easa/adequate-vertiport)
- [adult](https://avioverse.aero/glossary/easa/adult)
- [aero-medical assessment](https://avioverse.aero/glossary/easa/aero-medical-assessment)