Overview
EN ISO 340:2022 - Conveyor belts - Laboratory scale flammability characteristics - Requirements and test method (ISO 340:2022) specifies a small‑scale laboratory method to assess how conveyor belts react to an ignition flame source. Applicable to conveyor belts with a textile carcass and steel cord belts, the standard defines specimen preparation, test apparatus, safety precautions and pass/fail criteria for afterflame and re‑ignition. EN ISO 340:2022 supersedes the 2013 edition and is endorsed by CEN for national adoption across Europe.
Key topics and requirements
- Scope and caution: The test assesses ignition behaviour on a small scale; results help evaluate ignition hazard but should not be used alone to conclude overall fire safety.
- Test principle: A defined test piece is suspended vertically above a gas flame (LPG) for a specified time. After removal of the burner the afterflame time is measured and subsequent re‑flame under an air current is checked.
- Specimen preparation:
- Minimum distance from belt edge: 50 mm.
- For textile carcass belts: 12 test pieces, each (200 mm ± 5 mm) × (25 mm ± 1 mm):
- 3 longitudinal with covers intact
- 3 transverse with covers intact
- 3 longitudinal with covers removed
- 3 transverse with covers removed
- Covers removed by stripping, cutting or buffing (without overheating or damaging carcass).
- Acceptance criteria:
- Sum of afterflame times for six tests < 45 s and no single afterflame > 15 s.
- Flame shall not reappear when a current of air is applied.
- Note: In the European Single Market, these criteria may be replaced by the class requirements of EN 12882 or EN 14973.
- Health & safety:
- Controls for smoke and toxic fumes.
- Safe handling, storage and disposal of LPG cylinders; gas equilibration considerations.
Applications - who uses this standard
- Conveyor belt manufacturers for product development and quality control.
- Independent testing laboratories performing flammability testing and certification.
- Mine operators, bulk material handlers and OEMs specifying belts for installations where ignition risk must be evaluated.
- Procurement, safety engineers and regulators assessing compliance with regional flammability classes.
- Useful for comparing materials, covers and carcass constructions under a reproducible laboratory flammability test.
Related standards
- EN 12882 - Conveyor belts for general purpose use: electrical and flammability requirements
- EN 14973 - Conveyor belts for underground installations: electrical and flammability requirements
- ISO 8056‑1, ISO 9162 - referenced for apparatus and LPG specifications
Keywords: EN ISO 340:2022, conveyor belts, laboratory scale, flammability test, afterflame, textile carcass, steel cord, LPG, EN 12882, EN 14973.
