IEC 60721-3-6:2025

Overview

IEC 60721-3-6:2025 - Classification of environmental conditions, Part 3-6: Ship environments - defines the groups of environmental parameters and their severities to which electrotechnical products are exposed when installed aboard ships. This 2nd edition (2025) replaces the 1987 edition and introduces new, data‑driven classes for shipboard climatic, biological, chemical, mechanical and mechanically‑active substance environments. The scope covers all types and sizes of ships (from pleasure craft to tankers and icebreakers), inland waterways, coastal waters, oceans and ice navigation. Accidental incidents and water pressure effects on submerged products are excluded.

Key topics

• Classification framework: Defines classes for climatic (K), biological (B), chemically active (C), mechanically active substances (S) and mechanical (M) conditions. Classes can be combined (example format: 6K13/6B2/6C6/6S6/6M6).
• Updated classes and tables: Most classes were replaced with new classes based on referenced Technical Reports; Table 1–Table 5 updated to reflect current shipboard environmental data.
• Representative examples: Enclosed ship locations are categorized (e.g., 6K8 for fully air‑conditioned spaces, 6K9–6K11 for varying levels of temperature/humidity control and solar exposure; 6K12 for sheltered weatherprotected locations).
• Design and test guidance: The standard is intended to help select appropriate environmental severities for design, type testing and specification. It emphasizes combined environmental effects (e.g., temperature + humidity + vibration) and notes that short‑term extremes and long‑term ageing must both be considered.
• Normative links: Uses terms/requirements from IEC 60721‑1 and references technical reports (IEC TR 62130, IEC TR 62131‑8) for further environmental data.

Applications

Who uses IEC 60721-3-6:2025 and how:

• Product designers & manufacturers: Define environmental requirements for shipboard electronics, control systems and instrumentation; select materials and protective measures.
• Shipbuilders & integrators: Specify equipment classes for installation zones (e.g., machinery spaces vs. bridge vs. enclosed cabins).
• Test laboratories & certification bodies: Establish test severities and combined‑condition test schedules aligned with ship environment classes.
• Procurement & system engineers: Prepare procurement specifications and acceptance criteria based on standardized severities to ensure reliable operation across inland, coastal and ocean navigation. Practical benefits include consistent specification of shipboard environmental requirements, improved product reliability, and more targeted environmental testing.

Related standards

• IEC 60721‑1 - Classification of environmental conditions: Environmental parameters and their severities (normative reference).
• Other parts of the IEC 60721 series covering storage and transportation environmental conditions.
• Refer to IEC technical reports (IEC TR 62130, IEC TR 62131‑8) for background data used in the 2025 revision.

Keywords: IEC 60721-3-6, ship environments, classification of environmental conditions, shipboard equipment, climatic conditions K, electrotechnical products, environmental severities.