7 CFR § 51.752 - U.S. No. 1.
“U.S. No. 1” consists of grapefruit which meet the following requirements:
(a) Basic requirements:
(1) Discoloration: Not more than one-third of the surface, in the aggregate, may be affected by discoloration. (See § 51.770.);
(3) Fairly well colored;
(4) Firm;
(5) Mature;
(6) Similar varietal characteristics; and,
(7) Well formed.
(b) Free from:
(1) Decay;
(2) Unhealed skin breaks; and,
(3) Wormy fruit.
(c) Free from damage caused by:
(1) Ammoniation;
(2) Bruises;
(3) Buckskin;
(4) Caked melanose;
(5) Dirt or other foreign material;
(6) Disease;
(7) Dryness or mushy condition;
(8) Green spots;
(9) Hail;
(10) Insects;
(11) Oil spots;
(12) Scab;
(13) Scale;
(14) Scars;
(15) Skin breakdown;
(16) Sprayburn;
(17) Sprouting;
(18) Sunburn;
(19) Thorn scratches; and,
(20) Other means.
(d) For tolerances see § 51.760.