There are literally hundreds of different flammability tests from a wide variety of state, federal, international and private organizations. If you have any doubts about the performance of a particular building material, foam or otherwise, be sure to request a copy of the test report, which should include a description of the material test, the name of the test lab, the date of the test and the results.

ASTM E-84

The most common method of ranking a material's flammability is the class system. Materials are tested in accordance with ASTM E-84, the most commonly encountered fire test used to determine the flame spread and smoke density of a material while it is burned in an inclined tunnel.

Using the test results from ASTM E-84, foam and other building materials are rated as a Class I, Class II, or Class III material.

The Class rating system is based on two components, flame spread and smoke density. 

Flame spread rates how quickly fire travels across the material being burned. Flame spread  is rated on a scale from 1 to 100, with 1 being the lowest and 100 the highest.

Smoke density rates how thick smoke becomes when the material being tested is burned.

These measurement terms are meant for laboratory use. They do not correspond to, and cannot be compared with, actual "real-world" measurements. For example, a flame spread of 0 - 25 cannot be defined in inches or feet.

Class I-rated materials are the least flammable and will not catch fire when exposed to flame. They will turn to ash. Class 1-rated materials have a flame spread index of 0-25.

Class II-rated materials will flame but their fire retardant properties help extinguish flames as it burns. These materials have a flame spread of 26-75.

Class III-rated materials have the highest flammability, with a flame spread of 76-200.

In all classes the smoke density is limited to 450.

pinta's willtec® foam is Class 1 fire-rated according to ASTM E-84:

willtec Natural

Flame Spread: 5
Smoke Density: 50

willtec Painted

Flame Spread: 10
Smoke Density: 10

willtec Hypalon coated

Flame Spread: 25
Smoke Density: 65

colortec
Flame Spread: 5
Smoke Density: 90

NFPA 255

This is a test of the National Fire Protection Association and it is exactly the same as ASTM E-84.

UL1715

Another common test is UL 1715, commonly known as the corner burn test. This test is a more realistic indicator of how a material will perform in an actual fire. For this particular test, there are no numbers or rating systems. A material either passes or fails the test.

pinta's willtec foam tested according to UL1715

willtec natural: Passes
colortec: Passes
Painted and Hypalon coated versions have yet to be tested

For more information, click here to be linked to our complete foam tutorial.