40 CFR 211.210-1 - General requirements.
(a) Every hearing protector manufactured for distribution in commerce in the United States, and which is subject to this regulation:
(1) Must be labeled at the point of ultimate purchase or distribution to the prospective user according to the requirements of § 211.204 of this subpart; and
(2) Must meet or exceed the mean attenuation values determined by the procedure in § 211.206 and explained in § 211.211(b).
(b) Manufacturers who distribute protectors in commerce to another manufacturer for packaging for ultimate purchase or use must provide to that manufacturer the mean attenuation values and standard deviations at each of the one-third octave band center frequencies as determined by the test procedure in § 211.206. He must also provide the Noise Reduction Rating calculated according to § 211.207.