self-ignite

From self- +‎ ignite.

self-ignite (third-person singular simple present self-ignites, present participle self-igniting, simple past and past participle self-ignited)

1. (intransitive) To catch fire due to sufficient temperature.
   • 1983, Journal of Thermal Analysis:

     However, when the concentration of carbon is 1.4%, the mixture self-ignites at 295°.