ISO 26261-3:2017

Overview

ISO 26261-3:2017 - Fireworks - Category 4 - Part 3: Test methods specifies standardized test methods for fireworks classified as Category 4. The document defines the required test environment, measuring instruments, conditioning procedures and the methods to evaluate construction, stability, firing performance, sound pressure and other safety‑relevant characteristics for large, professional fireworks. It supports consistent, reproducible testing of Category 4 items for type and batch verification.

Key topics and technical requirements

• Scope and test environment
  • Tests must be performed in a large unobstructed area; wind speed measured at 1.50 m must be recorded and no testing if wind > 5.0 m/s.
  • Aquatic fireworks require a water test area for moisture resistance and functioning checks.
• Required apparatus
  • Timing device (0.1 s), calliper (0.1 mm), ruler (1 mm), measuring tape, wind speed meter (±0.5 m/s), balance (±0.01 g).
  • Temperature chambers up to (50 ± 2.5) °C and (75 ± 2.5) °C for thermal conditioning.
  • Class 1 sound level meter with free‑field microphone (IEC 61672‑1).
  • Shock apparatus with specified deceleration and impulse duration (see Annex A).
  • Height‑measuring devices (theodolite, electronic level, video/IR systems) - methods in Annex B.
• Construction and dimensional checks
  • Outer dimensions, calibre (measured ≥3 times with calliper), and gross mass procedures are specified.
  • Design verification against manufacturer drawings and record of nonconformities.
• Mortar and firing parameters
  • Mortar internal diameter/length requirements and permissible clearances (Q ratio). For most calibres Q must be ≤ 0.98; for calibre ≤ 100 mm Q range 0.83–0.98. Mortar length guidance and figures provided.
  • Fireworks to be fired vertically (90° ± 2°) for angle and burst height measurements.
• Conditioning and function tests
  • Mechanical conditioning (shock apparatus), thermal conditioning and function tests with monitoring of rise/burst/drop heights and effect ranges (aquatic fireworks guidance included).
• Sound measurement
  • Impulse A‑weighted sound pressure level measured with microphone at 1.0 m height oriented toward firing point.

Practical applications and users

Who uses ISO 26261-3:2017:

• Fireworks manufacturers - to perform design verification, batch and type testing.
• Independent test laboratories - to conduct standardized performance and safety tests for certification.
• Regulators and conformity assessors - to evaluate compliance with Category 4 safety requirements.
• Event organizers and professional pyrotechnicians - for understanding safe mortar selection, firing conditions and expected performance. Practical uses include establishing safe firing distances, validating mortar compatibility, verifying noise levels, and documenting proof of conformity for imports/market access.

Related standards

• ISO 26261-1 - Fireworks: Terminology (Part 1)
• ISO 26261-2:2017 - Fireworks: Category 4 - Part 2: Requirements
• ISO 13385-1 - Dimensional measuring equipment (callipers)
• IEC 61672-1 - Electroacoustics: Sound level meters

Keywords: ISO 26261-3:2017, fireworks Category 4 test methods, fireworks testing, mortar dimensions, sound pressure level, mechanical conditioning, thermal conditioning, function test, safety distance calculation.