Overview
ISO 21924-4:2017 - "Protective equipment for martial arts - Part 4: Additional requirements and test methods for head protectors" specifies additional safety, sizing and test requirements for head protectors without face protection used in unarmed martial arts (taekwondo, karate, kick‑boxing and similar disciplines) and for use in boxing. The standard complements ISO 21924-1 by defining performance limits, field‑of‑vision, restraint, zone‑of‑protection and impact test methods tailored to headgear used in martial arts.
Key topics and technical requirements
- Scope: Applies to head protectors without face protection for unarmed martial arts and boxing.
- Mass limits: Maximum mass varies with head circumference (examples from the standard):
- < 540 mm: max 360 g
- 540–560 mm: max 380 g
- 560–580 mm: max 400 g
-
580 mm: max 420 g
- Sizing & marking: Manufacturers must declare the head circumference range (cm) for which each model is intended and supply positioning information.
- Field of vision: Minimum vision angles when tested on EN 960 headforms:
- Horizontal: min 105° left and right from the longitudinal vertical median plane
- Upwards: min 25° from the reference plane
- Downwards: min 45° from the basic plane
- Restraint system: Must allow single‑person fitting, include adjusters, and limit displacement to less than 5% of head circumference after specified tests. Specific restraint test forces (20 N per test position) and test directions are defined.
- Zone of protection: Defined dimensions and locations relative to head circumference; manufacturers must indicate correct positioning and where protective zone lies on the outer shell.
- Impact performance: Peak force must be below 2 kN. Impact testing uses a defined apparatus (flat steel plate with central anvil, compression ring and guided striker). Test protocol includes multiple impacts of 3 J at specified positions. Measurement instrumentation requirements include ≥2 000 Hz sampling and load cell accuracy class 0.2 (max load 10 kN).
Applications and users
- Who uses this standard: PPE designers, manufacturers of martial‑arts headgear, test laboratories, sports equipment certifiers, competition regulators and sports organizations.
- Practical value: Ensures consistent safety, performance and labeling of head protectors; supports conformity assessment, product development, quality control and procurement for clubs, federations and retailers.
Related standards
- ISO 21924-1:2017 - General requirements and test methods for martial arts protective equipment (normative reference)
- EN 960 - Headforms for testing protective helmets
Keywords: ISO 21924-4:2017, martial arts head protectors, headgear test methods, impact performance, field of vision, restraint system, protective equipment for taekwondo, karate, boxing.