Maximum acceptable surface temperatures

The maximum acceptable surface temperatures for electrically operated toys shall be as follows:

Surface type (as described—in § 1505.6 (g)(2)) Thermal inertia type 1 Temperatures °C. °F. A 1 50 122 A 2 55 131 A 3 60 140 B 1 55 131 B 2 65 149 B 3 75 167 C (unmarked) 1 65 149 C (unmarked) 2 75 167 C (unmarked) 3 85 185 C (unmarked) 4 95 203 C marked 1 70 158 C marked 2 90 194 C marked 3 110 230 C marked 4 130 266 D (unmarked) 1 55 131 D (unmarked) 2 70 158 D (unmarked) 3 80 176 D (unmarked) 4 90 194 D marked 1 60 140 D marked 2 75 167 D marked 3 100 212 D marked 4 125 257 E (2) (3) (3) 1 Thermal inertia types are defined in terms of lambda as follows: Type 1: Greater than 0.0045 (e.g., most metals). Type 2: More than 0.0005 but not more than 0.0045 (e.g., glass). Type 3: More than 0.0001 but not more than 0.0005 (e.g., most plastics). Type 4: 0.0001 or less (e.g., future polymeric materials). The thermal inertia of a material can be obtained by multiplying the thermal conductivity (cal./cm./sec./degrees C.) by the density (gm./cm.3) by the specific heat (cal./gm./degrees C.). 2 All types. 3 No limit.