A tank is filled with chemicals undergoing an exothermic reaction. The reaction heats up the tank wall, and to prevent thermal burn on individuals, the tank’s outer surface temperature should be below 45°C. The emissivity of the tank surface is 0.85, and irradiation on the tank surface from the surroundings is estimated to be 390 W/m². A radiometer is placed normal to and at a distance of 0.5 m from the tank surface to monitor the surface temperature. The radiometer receives radiation from a target area of 1 cm² of the tank surface. If the irradiation measured by the radiometer is 0.085 W/m², determine whether or not the tank surface is safe to touch.