ISO 21482:2007

Overview

ISO 21482:2007 - Ionizing‑radiation warning: Supplementary symbol specifies a supplementary warning symbol to indicate the presence of a dangerous level of ionizing radiation from high‑level sealed radioactive sources. It does not replace the basic ionizing‑radiation trefoil (ISO 361 / ISO 7010) but supplements it by conveying the specific, life‑threatening hazard associated with IAEA Category 1, 2 and 3 sealed sources. The symbol was developed and tested internationally (including cross‑cultural and youth testing) to improve comprehension among untrained or uninformed members of the public.

Key topics and requirements

• Purpose: Warn of sources that can cause death or serious injury if mishandled; intended to discourage dismantling and unauthorized access.
• Design & colours: Red background (Pantone Red No. 187) with black figures and white outlines. Colourless (engraved) versions are permitted where colour is not feasible.
• Minimum size: Symbol should not be smaller than 3.0 cm to ensure visibility.
• Placement rules:
  • Place in close proximity to the sealed source - preferably on the source shield or near the point of potential access.
  • Ideally located under device covers or on shielding so it becomes visible if someone attempts disassembly.
  • May be engraved, labelled, mounted or attached as a tab; due to small source sizes, placing the symbol on device shielding is often preferable.
  • Do not place the symbol on external surfaces of transport packages, freight containers, conveyances or building access doors.
• Composition: Detailed graphical elements and proportions are specified in normative annex figures (Figures A.1–A.6).

Applications

• Use on housings, shields or access points of devices containing IAEA Category 1–3 sealed radioactive sources (e.g., industrial radiography devices, teletherapy heads, high‑activity calibration sources).
• Intended to reduce accidental exposure and fatalities by improving public recognition that the item is extremely dangerous.
• Useful for manufacturers, device designers, safety label suppliers, and maintenance contractors who handle or produce sealed source equipment.

Who should use this standard

• Radiation protection officers and health & safety managers
• Manufacturers of devices containing sealed radioactive sources
• Regulatory bodies and compliance auditors
• Designers of safety signage and labels for radioactive equipment

Related standards

• ISO 361 (Basic ionizing radiation symbol - trefoil)
• ISO 7010 (Graphical symbols - safety signs)
• IAEA Code of Conduct on Safety and Security of Radioactive Sources
• IAEA RS‑G‑1.9 (Categorization of Radioactive Sources)

Keywords: ISO 21482:2007, ionizing‑radiation warning, supplementary symbol, sealed radioactive source, IAEA Category 1 2 3, radiation safety, warning label.