Is the pencil core poisonous?

In China, the pronunciation of “pencil” is “qian bi” sonuds like the pencil is made of lead whose pronunciation is “qian”. So may Chinese refused, is the pencil core poisonous? In fact, the pencil core and no poison. 
The main component of core pencils is graphite and clay. Graphite is a metallic luster of the scale like solid, in which there is a carbon - carbon chemical bond between the layer and the layer is van Edward force, carbon - carbon chemical bond is very stable, it is very difficult to destroy. That's why diamond and graphite are made of carbon. But the physical nature and the price difference is very big, in the human body does not have the thing to be able to destroy the carbon - carbon chemical bond, therefore certainly said that the pencil core is safe.
But, is there a metal poison in the pencil rod? The appearance of a pencil rod wrapped by mold or pencil paint technology, on the one hand can protect the pen, on the other hand increase beauty, but the pigment will contain trace heavy metals, have the effect of contact not small, but bite pen mouth to eat is adverse.
In Longer, there is a production line manufacture pencil, it’s Wooden Pencil Production Line, this line including many machines, such as Side Sawing Machine, Groove Planning Machine, Core Glue Machine, Board Binding Machine, Pole Machine, Horizontal Polishing Machine, Double-belt Lacquer Machine,  Printing Machine, Double Side Acknowledging Printing Machine, Cutting Polishing Machine, Tip Polishing Machine, Saw Cutting Machine,  Single Rubber Tip Machine, Double Pieces Lacquer Machine, Insert Pencil Machine, Tip Immersing Machine
Production process can be summarized as:
1.Cutting board as fixed size
2. First, put the rectangular board in a machine for making pencils.
3. The machine can dig seven grooves on the board, and seven pencils can be produced.
4. Put the pencil core into the groove of the board.
5. Then use glue, glue another piece of wood to the existing lead core board.
6. In order to allow the board tightly together, this will be glued to the board of static air dry room, air dry for several hours.