ISO 8421-6:1987

Overview

ISO 8421-6:1987 - Fire protection - Vocabulary - Part 6: Evacuation and means of escape is an International Standard that defines terminology related to evacuation, escape routes and emergency egress. Prepared by ISO/TC 21 (Equipment for fire protection and fire fighting), this part provides precise English-language terms (alphabetically arranged) with a French index. General-use fire terms are covered in ISO 8421‑1. The standard standardizes language used by designers, safety professionals and regulators to reduce ambiguity in fire‑safety planning and documentation.

Key topics

ISO 8421-6 focuses on clear definitions rather than prescriptive design rules. Important topics and concepts covered include:

• Types of escape routes: external, pressurized, protected, enclosed and dead-end routes.
• Exit terminology: final exit, emergency/fire exit, exit unit of width (generally 500 or 600 mm).
• Evacuation measures: evacuation procedure/plan, evacuation drill, evacuation signal and evacuation time.
• Capacity and flow metrics: discharge value (unit and total/global), theoretical occupation density for exit sizing.
• Means and devices for descent/egress: escape ladder, escape rope, automatic lowering device, evacuation slide/toboggan and escape hatch.
• Supporting concepts: travel distance to protected routes or final exits, place of safety, fire brigade access window, emergency lighting and signage (see ISO 6309 for safety signs).
• Presentation details: English alphabetical order of terms, French index, and numbering convention (initial digit 6 indicates Part 6).

Applications

ISO 8421-6 is used to:

• Harmonize terminology in fire safety design documents, codes and standards.
• Ensure consistent communication among architects, building services engineers, fire safety engineers, facility managers, emergency planners, regulatory authorities and manufacturers of egress equipment.
• Support preparation of evacuation plans, risk assessments, emergency procedures and training exercises.
• Clarify definitions referenced by national building codes, standards for signage and egress geometry, and procurement/specification documents.

Related standards

• ISO 8421-1 - General terms and phenomena of fire (general-use terms).
• ISO 8421 Parts 2–8 - Structural fire protection; detection and alarm; fire extinction equipment; smoke control; evacuation (Part 6); explosion detection/suppression; fire-fighting/rescue and hazardous materials.
• ISO 6309 - Fire protection - Safety signs (related exit/direction signage).

Using ISO 8421-6:1987 in project documentation improves clarity, reduces misinterpretation and facilitates international alignment of fire‑safety language and emergency egress planning.