current density value for inductor used in boost converter
There is no industry standard as far as I know. You should not need to be too concerned by the current density in the copper. What is important to you as a designer is the DC resistance of the inductor as this will give losses resulting in heat dissipation in your inductor, a too high series resistance and it will get hot !

Another VERY IMPORTANT, perhaps even MORE IMPORTANT property of the inductor is the saturation current. What current can it handle ? If the current rises above this value, the magnetic core of the inductor will saturate and the inductor will start to behave like a (low-value) resistor. The inductor will not be able to store more magnetic energy.

Usually and fortunately if you select an inductor with a sufficiently high saturation current, the copper windings will be able to handle that current :-)

Have you read this: http://powerelectronics.com/content/guide-selecting-inductors-switching-regulators?page=1  ??