10 CFR § 429.29 - Showerheads.
(a)Sampling plan for selection of units for testing.
(1) The requirements of § 429.11 are applicable to showerheads; and
(2) For each basic model of a showerhead, a sample of sufficient size shall be randomly selected and tested to ensure that any represented value of water consumption of a basic model for which consumers favor lower values shall be greater than or equal to the higher of:
(i) The mean of the sample, where:
(ii) The upper 95 percent confidence limit (UCL) of the true mean divided by 1.05, where:
(1) The requirements of § 429.12 are applicable to showerheads; and
(2) Pursuant to § 429.12(b)(13), a certification report shall include the following public product-specific information: The maximum water use in gallons per minute (gpm) rounded to the nearest 0.1 gallon, the maximum flow water pressure in pounds per square inch (psi), and a declaration that the showerhead meets the requirements of § 430.32(p) pertaining to mechanical retention of the flow-restricting insert, if applicable.