U.S. No. 1 consists of onions which meet the following requirements:

(a) Basic requirements:

(1) Similar varietal characteristics, except color when designated as a specialty or mixed pack;

(2) Mature;

(3) Fairly firm; and,

(4) Fairly well shaped.

(b) Free from:

(1) Decay;

(2) Wet sunscald;

(3) Doubles; and,

(4) Bottlenecks.

(c) Free from damage caused by:

(1) Seedstems;

(2) Splits;

(3) Dry sunken areas;

(4) Sunburn;

(5) Sprouting;

(6) Staining;

(7) Dirt or foreign material;

(8) Mechanical;

(9) Tops;

(10) Roots;

(11) Translucent scales;

(12) Watery scales;

(13) Moisture;

(14) Disease;

(15) Insects; and,

(16) Other means.

(d) For size and tolerances see §§ 51.3198 and 51.3199.