40 CFR 211.204-1 - Information content of primary label.
(a) Area A must state “Noise Reduction Rating.”
(1) Area B must state the value of the Noise Reduction Rating (NRR) in decibels for that model hearing protector. The value stated on the label must be no greater than the NRR value determined by using the computation method of § 211.207 of this subpart.
(2) For devices with headbands that are intended for use with the headband in different positions, the worst case NRR must be specified. The top of Area B must state the position(s) associated with that NRR. The other positions and the respective NRRs must be included with the supporting information specified in § 211.204-4.
(c) Area C must contain the statement “The range of Noise Reduction Ratings for existing hearing protectors is approximately 0 to 30 (higher numbers denote greater effectiveness).”
(d) At the bottom of Area A-B, there must be the phrase “(When used as directed).”