Smoke-developed index is a measure of the concentration of smoke

Smoke

Smoke is a collection of airborne solid and liquid particulates and gases emitted when a material undergoes combustion or pyrolysis, together with the quantity of air that is entrained or otherwise mixed into the mass. It is commonly an unwanted by-product of fires , but may also be used for pest...

 a material emits as it burns. Like Flame Spread Index

Flame spread

Flame spread or surface burning characteristics rating is a ranking derived by laboratory standard test methodology of a material's propensity to burn rapidly and spread flames...

, it is based on an arbitrary scale in which asbestos-cement board has a value of 0, and red oak wood has 100.

The ASTM

ASTM International

ASTM International, known until 2001 as the American Society for Testing and Materials , is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, and services...

 standard E84 defines a standard test method for surface flame spread and smoke density measurements. A smoke-developed index between 0 and 450 is required by IBC

International Building Code

The International Building Code is a model building code developed by the International Code Council . It has been adopted throughout most of the United States.-History:...

section 803.1 for interior wall and ceiling finishes classes A, B and C.