1. Temperature condition: the explosion sensitivity of C4 explosive is closely related to temperature, and C4 explosive is most sensitive when its explosion sensitivity is between 20 and 50 degrees. Therefore, when detonating C4 explosive, the site temperature must meet the safety requirements.

2. Humidity condition: The explosion sensitivity of C4 explosive is also limited by humidity. When the relative humidity of the environment exceeds 65%, C4 explosive will explode. Therefore, when detonating C4 explosive, it is necessary to ensure that the humidity at the site is controlled within a safe range.