When sourcing smoke density testers, you must ensure compliance with international fire safety standards. The most critical benchmarks include ASTM E662 (Standard Test Method for Specific Optical Density of Smoke Generated by Solid Materials), ISO 5659-2 (Plastics — Smoke generation — Part 2: Determination of optical density by a single-chamber test), and BSI 6853 (Code of practice for fire precautions in the design and construction of passenger carrying trains). For cable testing, look for IEC 61034-1/2 compliance, which specifies the '3-meter cube' test method.