Class 4.2 – Spontaneously Combustible

p>This signage, denoting Class 4.2, pertains to substances prone to spontaneous combustion. Its purpose is to forewarn about materials of potential danger during transportation. Within Class 4.2 lie substances, both in solid and liquid forms, that possess the propensity to undergo spontaneous heating within the ordinary conditions experienced during transit. Furthermore, these substances could heat up upon interaction with air, subsequently becoming susceptible to ignition and combustion, as exemplified by phosphorus.