John Smith wrote on Sep 28
th, 2023 at 1:39pm:
...no worse than smoke from burning tyres ... is lee going to argue that we shouldn't use tyres
Not so. Emissions from burning Lithium-ion cells
are
far more toxic to humans than those from
burning rubber tyres.
At elevated temperature the fluorine content of the
electrolyte in LI-ion cells and, to some extent, other
parts of the battery such as the polyvinylidene
fluoride (PVdF) binder in the electrodes, can form
gases such as hydrogen fluoride HF, phosphorus
pentafluoride (PF5) and phosphoryl fluoride (POF3),
ranging between 20 and 200 mg/Wh of nominal
battery energy capacity.
A Tesla battery pack has a capacity of 95kWh, which
means if fully burned, could release 19g of fluorides
into the atmosphere. Which is why firemen
must wear
SCBA when attacking a Li-ion fire.
A lethal concentration of atmospheric hydrogen
fluoride is 30 ppm, whilst that released from a
burning vehicle is 170 ppm/10 mins.
The release of hydrogen fluoride from a Li-ion battery
fire can therefore be a severe risk and an even
greater risk in confined or semi-confined spaces.
Burning tyres also release significant amounts of toxic
pollutants into the air. These pollutants include sulphur
dioxide (SO2), nitrogen oxides (NOx), carbon
monoxide (CO), volatile organic compounds (VOCs),
and particulate matter (PM), including fine particles
known as PM2.5 (0.0025mm dia).
But none are immediate killers.