R.I. Gen. Laws § 23-24.1-6: Compliance required.

Whenever a standard established by the director under this chapter applicable to a household substance is in effect, it shall be in compliance with any federal regulation of it, and no political subdivision of the state shall have any authority either to establish or continue in effect, concerning that household substance, any standard for special packaging (and any exemption from it and requirement related to it) which is not identical to the standard established under § 23-24-3 (and any exemptions from it and requirement related to it).