1.1 This Standard specifies a method measuring smoke production from the exposed
surface of specimens of essentially flat materials, composites or assemblies not exceeding
25 mm in thickness when placed in a horizontal orientation and subjected to specified
levels of thermal irradiance in a closed single chamber (hereafter referred to as
"chamber") with or without the application of a pilot flame. This method of test is ap-
plicable to all plastics and may also be used for the evaluation of other materials (e.g.
rubbers, textile-coverings, painted surfaces, wood and other materials).
1.2 It is intended that the values of optical density determined by this test be taken
as specific to the specimen or assembly material in the form and thickness tested, and
are not to be considered inherent, fundamental, properties.
1.3 The test is intended primarily for use in research and development and in fire
safety engineering of buildings, trains, ships, etc., and not as a basis for ratings for
building codes or other purposes. No basis is provided for predicting the density of
smoke that may be generated by the materials upon exposure to heat and flame under
other (actual) exposure conditions, nor is any correlation established with measurements
derived from other test methods. This test procedure excludes the effect of irritants
on the eye.
NOTE : This test procedure addresses the loss of visibility due to smoke density,
which generally is not related to irritancy potency, as explained in ISO
5659-1.
1.4 It is emphasized that smoke production from a material varies according to the
irradiance level to which the specimen is exposed. In making use of the results of this
method, it should be borne in mind that the results are based on exposure to the spe-
cific irradiance levels of 25 kW/m and 50 kW/m.
JIS K 7242-2:2008 Referenced Document
ISO 13943 Fire safety — Vocabulary*， 2023-09-01 Update
ISO 291 Plastics - Standard atmospheres for conditioning and testing
ISO 5659-1 Plastics - Smoke generation - Part 1: Guidance on optical-densitiy testing
JIS K 7242-2:2008 history
2015JIS K 7242-2:2015 Plastics -- Smoke generation -- Part 2: Determination of optical density by a single-chamber test
2008JIS K 7242-2:2008 Plastic -- Smoke generation -- Part 2 : Determination of optical density by a single-chamber test
1998JIS K 7242-2:1998 Plastics -- Smoke generation -- Part 2: Determination of optical density by a single-chamber test