Risk Matrix Reference 2026 — 5x5 + 4x4 + 3x3 with ALARP Zones

Machine-readable reference dataset providing fully populated risk matrices in three common configurations: 5×5 matrix (25 risk score combinations): 5 severity levels × 5 likelihood levels = risk score 1–25, mapped to bands (Very Low / Low / Medium / High / Very High) and ALARP zones. 4×4 matrix (16 combinations): compact format commonly used in UK and Australian construction, facilities management, and general industry. 3×3 matrix (9 combinations): simplified format used in small business, toolbox talk risk assessments, and qualitative pre-task assessments. Each row records: matrix size, severity level and descriptor, likelihood level and descriptor, risk score, risk band, ALARP zone (Broadly Acceptable / Tolerable (ALARP) / Intolerable), and recommended management action. ALARP (As Low As Reasonably Practicable) zones follow UK HSE and HSE-aligned industry convention: green zone = broadly acceptable, yellow/orange = tolerable with ALARP demonstration, red = intolerable (stop/prohibit). Useful for: risk assessment procedure development, AI training data for risk classification, ARIA AI assistant grounding, HSE management system templates, training curricula for ISO 31000 and NEBOSH risk-assessment modules. Sources: ISO 31000:2018 (risk management principles), UK HSE five-step risk assessment, OGUK Bowtie/ALARP guidance, IOGP Report 510. Published as part of the SmartQHSE Open HSE Data collection.