the oxygen index (CI, OxygenIndex, OI)
Oxygen index - the percentage of oxygen in the air, at which the material begins to maintain a candle-like steady flame combustion.
The oxygen content in the air is 21%.
CI <21%: highly flammable material
CI >> 21%: hardly flammable
Examples:
CI <21% (PMMA, PE, PP, PS, UPS, SAN, ABC + PMMA)
CI> 21% (PC, SEC, PETG, PVC)
Standard UL-94 (United States, Understanding Laboratory 94, Global Engineering Documents 800-854-7179):
UL 94HB (Horizontal Burning Test) - horizontal combustion
UL 94V (Vertical Burning Test) - vertical combustion:
94V-0 (lowest flammability)
94V-1
94V-2 (maximum flammability)
Examples:
Commonly used materials used in the advertising industry, most often the combustibility category 94HB and 94V-2, which corresponds to the class of materials with medium flammability.
DIN 4102 - classification of flammability of building materials of the German Institute of Standards.
A1 - 100% non-combustible materials
A2 - non-combustibility of ~ 98% (Non-combustible materials)
B1 - Not easily flammable
B2 - normal flammability, eg wood (Flammable)
B3 - Easilyflammable
GOST
To determine the fire risk of a material and the possibility of using it in various areas of the advertising and construction industry, in accordance with the requirements of GOSPozhNadzor bodies, it is necessary to conduct special tests for the corresponding GOSTs. Based on the results of such tests, a number of standard indicators are determined on special "certified" installations, the totality of which determines the fire safety of this particular material. The main of such indicators are the flammability group, the flammability group, the smoke-forming ability group in combustion, the combustion products toxicity group. The fire hazard of the material is determined by a combination of all the four above-mentioned indices-G, B, T, and D.
The combustibility group of materials is determined in accordance with GOST 30244-94 "Building materials - methods of testing for combustibility", which corresponds to the International standard ISO 1182-80 "Firetests - Buildingmaterials - Non-combastibilitytest". Materials, depending on the values of the flammability parameters determined by this GOST, are divided into non-combustible (NG) and combustible (D).
The materials are classified as non-flammable at the following values of the flammability parameters:
· Increase in temperature in the furnace no more than 50 ° С;
· Loss of sample mass not more than 50%;
· Duration of stable burning combustion is not more than 10 seconds.