Fluorocarbons decompose when directly exposed to high temperatures. For example, flames and electric resistance heaters will cause pyrolysis of fluorocarbon vapors. The products of this decomposition in the air include halogens, halogen acids (hydrochloric, hydrobromic) and
other irritating compounds. Although much more toxic than the fluorocarbon that gave rise to them, these decomposition products irritate the nose, eyes and upper airways, which means a warning of their presence.
The risk, in practice, is relatively small, as it is difficult for a person to voluntarily remain in the presence of decomposition products in concentrations that may cause physiological damage.
When these irritating fluorocarbon products are detected, the area must be evacuated, ventilated and the cause of the problem must be remedied.
Such thermal decomposition products can, for example, be formed when vapors are attracted by lit tobacco. Therefore, smoking is not permitted in the presence of fluorocarbon vapors.
