The simple answer is yes. You need to clean it up as soon as possible. If you fail to clean up your spill promptly and the chemical you spill is a hazardous waste (it exhibits one or more of the hazardous waste characteristics or it is a listed waste), EPA will consider your site to be a hazardous waste disposal site and you will be subject to all the permitting requirements of a RCRA facility.
In other words, you can be cited for operating a RCRA Treatment and Storage Disposal Facility without a permit!
The agency is pretty clean on that. Just read its guidance document RO 12748 in RCRA Online.