Help make lives and property safer and stay compliant by using the latest testing criteria for evaluating the extent of smoke obscuration of specimens.

NFPA^® 270, Standard Test Method for Measurement of Smoke Obscuration Using a Conical Radiant Source in a Single Closed Chamber, is an essential resource for fire test labs and manufacturers. The updated 2023 edition offers the most current methods of measuring the optical density of smoke resulting from exposing flat materials, products, or assemblies up to 25 mm thick to specified levels of thermal irradiance in a single closed chamber.

Changes to the standard include:

• Revisions to improve consistency with ASTM E1995, Standard Test Method for Measurement of Smoke Obscuration Using a Conical Radiant Source in a Single Closed Chamber, With the Test Specimen Oriented Horizontally
• Updates to referenced standards to reflect the latest knowledge