Overview
ISO 17049:2013 - Accessible design - Application of braille on signage, equipment and appliances - specifies fundamental requirements and practical guidance for applying braille on signs, equipment and appliances to ensure tactile readability and safety. The standard covers dimensional parameters (dot, cell and line spacing), braille dot geometry and material/placement considerations for durable, usable tactile information in public and private environments.
Key topics and technical requirements
- Braille cell and spacing: specifies dot and cell spacing ranges:
- Vertical dot spacing (a): 2.2–2.8 mm
- Horizontal dot spacing (b): 2.0–2.8 mm
- Cell spacing (p): 5.1–6.8 mm
- Line spacing (q): 10.0–15.0 mm
- Braille dot geometry:
- Base diameter (d): 1.0–1.7 mm
- Perpendicular height (h): 0.3–0.7 mm (recommend h > 0.5 mm for outdoor use and transport vehicles)
- Dot profile must be rounded, not flat or pointed.
- Exclusion zones:
- Minimum 6 mm exclusion zone around isolated braille cells.
- For signage and control labelling, specified cell-based exclusion spacing (e.g., 2+ cells between adjoined controls; 1.5 cells minimum in tight spaces).
- Layout and orientation:
- Braille must follow the reading order of the language (e.g., left-to-right where applicable).
- Do not place braille diagonally, inverted or on curved surfaces that impede tactile reading.
- Signage limits:
- Single-column lines: max 40 cells.
- Multi-column lines: max 40 cells per column and 80 cells total; three-or-more cell exclusion zone between columns.
- Controls and appliances:
- Braille should be on the same surface as controls; usually not on buttons (exceptions allowed when buttons are indistinguishable by touch and risk of accidental operation is low).
- Placement guidance for handrails (parallel to rail, read-friendly area; handrail extensions preferably ≥ 300 mm).
Practical applications and who uses it
ISO 17049 is applicable to:
- Accessibility consultants and standards compliance officers
- Product designers and manufacturers of appliances, ATMs, kiosks, lifts and consumer electronics
- Architects, building designers and signage suppliers for public buildings and transport hubs
- Public transport authorities and facility managers implementing tactile wayfinding
Use cases include tactile signage, handrail labels, control panels for household/office equipment, and safety/wayfinding labels where braille improves accessibility for blind and vision-impaired users.
Related standards
Relevant references include ISO 9999, ISO 21542, ISO 23599, ISO/IEC 7811‑9, EN 15823, ANSI A117.1 and national braille/dimension standards (e.g., DIN, JIS, GB/T). These provide complementary guidance on assistive products, tactile walking surface indicators and regulatory accessibility requirements.
Keywords: ISO 17049, braille dimensions, accessible design, tactile readability, signage, equipment, appliances, exclusion zone, braille spacing.
