PN-EN 50305
Laboratory
THE
TOXICITY TEST FOR THERMAL DECOMPOSITION AND COMBUSTION PRODUCTS OF
CABLES WITH
A METHODS ACCORDING TO PN-EN 50305, NF X70-100-1 I NF X70-100-2
The
principle of the method
consists in the quantitative determination of the products of thermal
decomposition and combustion of materials decisive for the toxicity
of the fire environment. The thermal decomposition and combustion of
samples of the test material shall be carried out in horizontal tube
furnace (Fig 1) at temperature 800oC.
At the time of the test, the specific mass emissions of CO2,
HCN, NO, NO2,
SO2
, HCl, HBr and HF shall be determined, which means the mass of the
toxic product produced during the thermal decomposition and
combustion of the material mass unit in the test conditions
concerned.
Stand
for testing the toxicity of the products of decomposition and
combustion of cables
The
FTIR analyzer is used to measure the specific mass emission, which
measures continuously the mass concentration – cmi
of
the CO, CO2,
HCN, NO, NO2,
SO2,
HCl, HBr and HF in the flowing products of the thermal decomposition
and the combustion of the material sample. On
this basis, for the mass of sample and the volume flow rate of the
gases, the control-measuring system shall determine the mass emission
only for CO, CO2,
HCN, NO, NO2,
SO2. These
values allow the conventional toxicity index CITC
for cables to be determined.
In
accordance with the requirements of PN-EN 50305, the cable sheaths
should be without halogen products. The lack HCl, HBr and HF of
cables thermal degradation and burning is a confirmation of this
requirement.
Test specimen. The test at each temperature must be prepared after 3 samples. The mass of the sample should be 1+/-0.05 g. For materials for which compliance with these requirements is not possible, smaller samples with a mass of 0.500g+/-0.050g or 0.250g+/-0.050g.
Samples must be prepared using the appropriate processing method for the material or by cutting or taking out of the finished product while maintaining the representativeness of the layers.
Applying research methods: railways (according to: R15 and R16 requirements of the norm PN-EN 45545-2 and PN-EN 50305).