Scuba(normally) does not use any higher concentration of oxygen than air. The compressors used just pump high pressure air into the tanks. Using a scuba tank f

Scuba(normally) does not use any higher concentration of oxygen than air. The compressors used just pump high pressure air into the tanks. Using a scuba tank filled with air does not pose any additional explosion risk due to oxygen. The only additional explosion risk is due to the relatively high pressures involved (2000-5000psi) and the risks surrounding the use of any compressed gas. There are blends of gasses available that do present an additional explosion hazard, but those are generally not available to someone without the training required to safely handle. For that matter a scuba shop following the rules won't even fill a tank of air for you without verifying your certification.