ISO 20712-2:2007

Overview

ISO 20712-2:2007 - "Water safety signs and beach safety flags - Part 2" specifies the shape, colour, meaning and performance requirements for beach safety flags used to manage coastal and inland beach activities. The standard standardizes flag meanings (e.g., danger, lifeguard-patrolled zone, craft zone), defines flag dimensions and shapes (rectangular and truncated-cone), and sets material, colourimetric/photometric and durability performance criteria to ensure consistent, recognisable water-safety signalling.

Key topics and technical requirements

• Flag meanings and colours
  • Red rectangle: severe hazard - no swimming.
  • Yellow rectangle: general warning (supplementary sign recommended).
  • Red/yellow horizontal rectangle: lifeguard-patrolled swimming/bodyboarding zone or lifeguard on duty.
  • Black/white quartered rectangle: surfboard and watercraft zone or boundary.
  • Red/white quartered rectangle: emergency evacuation - leave the water.
  • Orange truncated cone: no inflatables in water.
• Dimensions
  • Rectangular flags: minimum 750 mm × 900 mm; width must exceed height by 20–35% of height.
  • Conical (truncated cone) flags: minimum length 1 500 mm; small-end diameter ≥ 250 mm; large-end diameter ≥ 500 mm; ratio large:small:length = 2:1:6.
• Materials
  • Rectangular flags: polyester (ISO 2076), woven or knitted.
  • Conical flags: nylon conforming to BS 2F 127.
  • Woven polyester mass per unit area ≈ 155 ± 8 g/m²; knitted polyester ≈ 115 ± 6 g/m².
  • Woven thread counts and knitted wales/courses specified for fly and durability.
• Colourimetric and photometric properties
  • Chromaticity coordinates and luminance factor requirements are defined (tested per CIE/ISO methods) to ensure consistent, visible colours under standard illuminant D65.
• Durability and strength
  • Colour fastness: to light (ISO 105‑B02) and weathering (ISO 105‑B03) ratings ≥ 6; to fresh and salt water (ISO 105‑E01/E02) ratings ≥ 4–5; rubbing (ISO 105‑X12) staining rating 5.
  • Strength: woven tensile maximum forces - ~1 050 N (warp) and ~825 N (weft); knitted bursting strength per ISO 13938‑1.

Applications and practical value

• Ensures consistent, internationally recognisable beach safety flags used by:
  • Lifeguard services and coastal safety authorities
  • Municipal beach managers and tourism operators
  • Flag manufacturers and textile suppliers
  • Safety regulators and auditors
• Benefits: improved public safety, reduced confusion across jurisdictions, standard specifications for procurement and testing, and clearer incident response communication.

Related standards

• ISO 20712-1: water safety signs for workplaces/public areas
• ISO 20712-3: guidance for use
• Normative test references (selected): ISO 105 series (colour fastness), ISO 13934-1 (tensile), ISO 13938-1 (bursting), ISO 2076 (polyester fibres)

Keywords: ISO 20712-2:2007, beach safety flags, water safety signs, flag dimensions, colour fastness, colourimetric properties, polyester flags, lifeguard flags, beach safety standard.