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 1Temperatures
°C.°F.
A150122
A255131
A360140
B155131
B265149
B375167
C (unmarked)165149
C (unmarked)275167
C (unmarked)385185
C (unmarked)495203
C marked170158
C marked290194
C marked3110230
C marked4130266
D (unmarked)155131
D (unmarked)270158
D (unmarked)380176
D (unmarked)490194
D marked160140
D marked275167
D marked3100212
D marked4125257
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.