United States 

Department of 

Agriculture 

Marketing and 

Regulatory 

Programs 

Agricultural 

Marketing 

Service 

Poultry 

Programs 

United States Standards, 

Grades, and Weight 

Classes for Shell Eggs

AMS 56 

Effective July 20, 2000
FOREWORD

These standards, grades, and weight classes have been developed and are promulgated 

pursuant to the authorities contained in the Agricultural Marketing Act of 1946, as amended (7 

U.S.C. 1621 et seq.). The voluntary USDA shell egg grading program operates under these 

standards, grades, and weight classes as well as the shell egg grading regulations. The voluntary 

program provides for interested parties a national grading service based on official U.S. 

standards, grades, and weight classes for shell eggs. The costs involved in furnishing this 

grading program are paid by the user of the service. 

The grading program, regulations, standards, grades, and weight classes establish a basis 

for quality and price relationship and enable more orderly marketing. Consumers can purchase 

officially graded product with the confidence of receiving quality in accordance with the official 

identification. 

The Regulations Governing the Voluntary Grading of Shell Eggs are printed in the Code 

of Federal Regulations (CFR) as 7 CFR Part 56. The regulations are also available on the 

Internet at www.ams.usda.gov/poultry/regulations. 

The United States Standards, Grades, and Weight Classes for Shell Eggs were removed 

from the CFR on December 4, 1995. They are maintained by the Agricultural Marketing 

Service, U.S. Department of Agriculture, as AMS 56. This document contains the standards, 

grades, and weight classes that are the most current to date. Past changes are enumerated in the 

bracketed footnotes following the applicable sections. This document is also available on the 

Internet at www.ams.usda.gov/poultry. Look under Publications 

For printed copies of the regulations or the standards, grades and weight classes: 

Call: (202) 720-2356 

Fax: (202) 690-2930 

Write: USDA, AMS, Poultry Programs 

STOP 0259, Room 3944-South 

1400 Independence Avenue, SW 

Washington, DC 20250-0259 

The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on 

the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, 

parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of 

an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all 

programs.) Persons with disabilities who require alternative means for communication of program information 

(Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). 

To file a complaint of discrimination write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, 

S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal 

opportunity provider and employer
United States Standards, Grades, and Weight Classes for Shell Eggs 

AMS 56 - July 20, 2000 

1

AMS-56 

United States Standards, Grades, and Weight Classes for Shell Eggs 

 

Section Page 

United States Standards for Quality of Individual Shell Eggs

56.200 Application ................................................................................................................... 2 

56.201 AA Quality ................................................................................................................... 2 

56.202 A Quality ...................................................................................................................... 2 

56.203 B Quality ...................................................................................................................... 2 

56.205 Dirty .............................................................................................................................. 3 

56.206 Check ............................................................................................................................ 3 

56.208 Terms descriptive of the shell ...................................................................................... 3 

56.209 Terms descriptive of the air cell ................................................................................... 3 

56.210 Terms descriptive of the white ..................................................................................... 4

56.211 Terms descriptive of the yolk ....................................................................................... 5 

56.212 General terms ............................................................................................................... 5 

United States Grades and Weight Classes for Shell Eggs

56.215 General ......................................................................................................................... 6 

United States Consumer Grades and Weight Classes for Shell Eggs

56.216 Grades ........................................................................................................................... 6 

56.217 Summary of grades ....................................................................................................... 8 

56.218 Weight classes .............................................................................................................. 9 

United States Nest-Run Grade and Weight Classes for Shell Eggs

56.230 Grade ............................................................................................................................ 9 

56.231 Summary of grade ........................................................................................................ 10 

56.232 Weight classes .............................................................................................................. 11 

Authority: 7 U.S.C. 1621-1627. 

Summary of U.S. Standards for Quality of Individual Shell Eggs 

Shell Eggs ..................................................................................................................................... 12 
United States Standards, Grades, and Weight Classes for Shell Eggs 

AMS 56 - July 20, 2000 

2

United States Standards for Quality of Individual Shell Eggs

§56.200 Application.

(a) The United States standards for quality of individual shell eggs contained in this 

subpart are applicable only to eggs that are the product of the domesticated chicken hen and are 

in the shell. 

(b) Interior egg quality specifications for these standards are based on the apparent 

condition of the interior contents of the egg as it is twirled before the candling light. Any type or 

make of candling light may be used that will enable the particular grader to make consistently 

accurate determination of the interior quality of shell eggs. It is desirable to break out an 

occasional egg and by determining the Haugh unit value of the broken-out egg, compare the 

broken-out and candled appearance, thereby aiding in correlating candled and broken-out 

appearance. 

[28 FR 6346, June 20, 1963. Redesignated at 42 FR 32514, June 27, 1977, and amended at 46 FR 39571, Aug. 4, 

1981. Redesignated at 46 FR 63203, Dec. 31, 1981]

§56.201 AA Quality.

The shell must be clean, unbroken, and practically normal. The air cell must not 

exceed 1/8 inch in depth, may show unlimited movement, and may be free or bubbly. The white 

must be clear and firm so that the yolk is only slightly defined when the egg is twirled before the 

candling light. The yolk must be practically free from apparent defects. 

[38 FR 26798, Sept. 26, 1973. Redesignated at 42 FR 32514, June 27, 1977, and at 46 FR 63203, Dec. 31, 1981]

§56.202 A Quality.

The shell must be clean, unbroken, and practically normal. The air cell must not 

exceed 3/16 inch in depth, may show unlimited movement, and may be free or bubbly. The 

white must be clear and at least reasonably firm so that the yolk outline is only fairly well 

defined when the egg is twirled before the candling light. The yolk must be practically free from 

apparent defects. 

[38 FR 26798, Sept. 26, 1973. Redesignated at 42 FR 32514, June 27, 1977, and at 46 FR 63203, Dec. 31, 1981]

§56.203 B Quality.

The shell must be unbroken, may be abnormal, and may have slightly stained areas. 

Moderately stained areas are permitted if they do not cover more than 1/32 of the shell surface if 

localized, or 1/16 of the shell surface if scattered. Eggs having shells with prominent stains or 

adhering dirt are not permitted. The air cell may be over 3/16 inch in depth, may show unlimited 

movement, and may be free or bubbly. The white may be weak and watery so that the yolk 

outline is plainly visible when the egg is twirled before the candling light. The yolk may appear 
United States Standards, Grades, and Weight Classes for Shell Eggs 

AMS 56 - July 20, 2000 

3

dark, enlarged, and flattened, and may show clearly visible germ development but no blood due 

to such development. It may show other serious defects that do not render the egg inedible. 

Small blood spots or meat spots (aggregating not more than 1/8 inch in diameter) may be 

present. 

[46 FR 39571, Aug. 4, 1981; 46 FR 42441, Aug. 21, 1981. Redesignated at 46 FR 63203, Dec. 31, 1981]

§56.205 Dirty.

An individual egg that has an unbroken shell with adhering dirt or foreign material, 

prominent stains, or moderate stains covering more than 1/32 of the shell surface if localized, or 

1/16 of the shell surface if scattered. 

[46 FR 39571, Aug. 4, 1981. Redesignated at 46 FR 63203, Dec. 31, 1981]

§56.206 Check.

An individual egg that has a broken shell or crack in the shell but with its shell 

membranes intact and its contents do not leak. A "check" is considered to be lower in quality 

than a "dirty." 

[32 FR 8232, June 8, 1967. Redesignated at 42 FR 32514, June 27, 1977, and at 46 FR 63203, Dec. 31, 1981] 

§56.208 Terms descriptive of the shell.

(a) Clean. A shell that is free from foreign material and from stains or discolorations 

that are readily visible. An egg may be considered clean if it has only very small specks, stains, 

or cage marks, if such specks, stains, or cage marks are not of sufficient number or intensity to 

detract from the generally clean appearance of the egg. Eggs that show traces of processing oil 

on the shell are considered clean unless otherwise soiled. 

(b) Dirty. A shell that is unbroken and that has dirt or foreign material adhering to its 

surface, which has prominent stains, or moderate stains covering more than 1/32 of the shell 

surface if localized, or 1/16 of the shell surface if scattered. 

(c) Practically normal (AA or A quality). A shell that approximates the usual shape 

and that is sound and is free from thin spots. Ridges and rough areas that do not materially affect 

the shape and strength of the shell are permitted. 

(d) Abnormal (B quality). A shell that may be somewhat unusual or decidedly 

misshapen or faulty in soundness or strength or that may show pronounced ridges or thin spots. 

[46 FR 39571, Aug. 4, 1981. Redesignated at 46 FR 63203, Dec. 31, 1981]

§56.209 Terms descriptive of the air cell.
United States Standards, Grades, and Weight Classes for Shell Eggs 

AMS 56 - July 20, 2000 

4

(a) Depth of air cell (air space between shell membranes, normally in the large end of 

the egg). The depth of the air cell is the distance from its top to its bottom when the egg is held 

air cell upward. 

(b) Free air cell. An air cell that moves freely toward the uppermost point in the egg 

as the egg is rotated slowly. 

(c) Bubbly air cell. A ruptured air cell resulting in one or more small separate air 

bubbles usually floating beneath the main air cell. 

[38 FR 26798, Sept. 26, 1973. Redesignated at 42 FR 32514, June 27, 1977, and at 46 FR 63203, Dec. 31, 1981]

§56.210 Terms descriptive of the white.

(a) Clear. A white that is free from discolorations or from any foreign bodies floating 

in it. (Prominent chalazas should not be confused with foreign bodies such as spots or blood 

clots.) 

(b) Firm (AA quality). A white that is sufficiently thick or viscous to prevent the yolk 

outline from being more than slightly defined or indistinctly indicated when the egg is twirled. 

With respect to a broken-out egg, a firm white has a Haugh unit value of 72 or higher when 

measured at a temperature between 45 o

 and 60 oF. 

(c) Reasonably firm (A quality). A white that is somewhat less thick or viscous than a 

firm white. A reasonably firm white permits the yolk to approach the shell more closely which 

results in a fairly well defined yolk outline when the egg is twirled. With respect to a broken-out 

egg, a reasonably firm white has a Haugh unit value of 60 up to, but not including, 72 when 

measured at a temperature between 45 o and 60 oF. 

(d) Weak and watery (B quality). A white that is weak, thin, and generally lacking in 

viscosity. A weak and watery white permits the yolk to approach the shell closely, thus causing 

the yolk outline to appear plainly visible and dark when the egg is twirled. With respect to a 

broken-out egg, a weak and watery white has a Haugh unit value lower than 60 when measured 

at a temperature between 45 o and 60 oF. 

(e) Blood spots or meat spots. Small blood spots or meat spots (aggregating not more 

than 1/8 inch in diameter) may be classified as B quality. If larger, or showing diffusion of 

blood into the white surrounding a blood spot, the egg shall be classified as Loss. Blood spots 

shall not be due to germ development. They may be on the yolk or in the white. Meat spots may 

be blood spots which have lost their characteristic red color or tissue from the reproductive 

organs. 

 (f) Bloody white. An egg which has blood diffused through the white. Eggs with 

bloody whites are classed as Loss. Eggs with blood spots which show a slight diffusion into the 

white around the localized spot are not to be classed as bloody whites. 
United States Standards, Grades, and Weight Classes for Shell Eggs 

AMS 56 - July 20, 2000 

5

[20 FR 676, Feb. 1, 1955, as amended at 31 FR 2774, Feb. 16, 1966; 42 FR 2971, Jan. 14, 1977. Redesignated at 42 

FR 32514, June 27, 1977, and amended at 46 FR 39571, Aug. 4, 1981. Redesignated at 46 FR 63203, Dec. 31, 1981; 

65 FR 38239, June 20, 2000]

§56.211 Terms descriptive of the yolk.

(a) Outline slightly defined (AA quality). A yolk outline that is indistinctly indicated 

and appears to blend into the surrounding white as the egg is twirled. 

(b) Outline fairly well defined (A quality). A yolk outline that is discernible but not 

clearly outlined as the egg is twirled. 

(c) Outline plainly visible (B quality). A yolk outline that is clearly visible as a dark 

shadow when the egg is twirled. 

(d) Enlarged and flattened (B quality). A yolk in which the yolk membranes and 

tissues have weakened and/or moisture has been absorbed from the white to such an extent that 

the yolk appears definitely enlarged and flat. 

(e) Practically free from defects (AA or A quality). A yolk that shows no germ 

development but may show other very slight defects on its surface. 

(f) Serious defects (B quality). A yolk that shows well developed spots or areas and 

other serious defects, such as olive yolks, which do not render the egg inedible. 

(g) Clearly visible germ development (B quality). A development of the germ spot on 

the yolk of a fertile egg that has progressed to a point where it is plainly visible as a definite 

circular area or spot with no blood in evidence. 

(h) Blood due to germ development. Blood caused by development of the germ in a 

fertile egg to the point where it is visible as definite lines or as a blood ring. Such an egg is 

classified as inedible. 

[46 FR 39571, Aug. 4, 1981. Redesignated at 46 FR 63203, Dec. 31, 1981]

§56.212 General terms.

(a) Loss. An egg that is inedible, cooked, frozen, contaminated, musty, or moldy, or 

an egg that contains a large blood spot, large meat spot, bloody white, green white, rot, sour 

eggs, stuck yolk, blood ring, embryo chick (at or beyond the blood ring state), free yolk in the 

white, or other foreign material, or an egg that is adulterated as such term is defined pursuant to 

the Federal Food, Drug, and Cosmetic Act. 

(b) Leaker. An individual egg that has a crack or break in the shell and shell 

membranes to the extent that the egg contents are exuding or free to exude through the shell. 
United States Standards, Grades, and Weight Classes for Shell Eggs 

AMS 56 - July 20, 2000 

6

[20 FR 677, Feb. 1, 1955, as amended at 31 FR 2774, Feb. 16, 1966; 32 FR 8232, June 8, 1967. Redesignated at 42 

FR 32514, June 27, 1977, and at 46 FR 63203, Dec. 31, 1981, and amended at 47 FR 46070, Oct. 15, 1982; 47 FR 

54421, Dec. 3, 1982; 65 FR 38239, June 20, 2000]

United States Grades and Weight Classes for Shell Eggs

§56.215 General.

(a) These grades are applicable to edible shell eggs in "lot" quantities rather than on 

an "individual" egg basis. A lot may contain any quantity of two or more eggs. Reference in 

these standards to the term "case" means 30-dozen egg cases as used in commercial practices in 

the United States. The size of the sample used to determine grade shall be on the basis of the 

requirements of 7 CFR Part 56.4 or as determined by the National Supervisor. 

(b) Terms used in this part that are defined in the United States Standards for Quality 

of Individual Shell Eggs (AMS 56.200 et seq.) have the same meaning in this part as in those 

standards. 

(c) Aggregate tolerances are permitted within each grade only as an allowance for 

variable efficiency and interpretation of graders, normal changes under favorable conditions 

during reasonable periods between grading, and reasonable variation of graders' interpretation. 

(d) Substitution of higher qualities for the lower qualities specified is permitted. 

(e) "No grade" means eggs of possible edible quality that fail to meet the requirements 

of an official U.S. Grade or that have been contaminated by smoke, chemicals, or other foreign 

material which has seriously affected the character, appearance, or flavor of the eggs. 

[20 FR 677, Feb. 1, 1955, as amended at 28 FR 6346, June 20, 1963; 32 FR 8232, June 8, 1967. Redesignated at 42 

FR 32514, June 27, 1977, and amended at 46 FR 39571, Aug. 4, 1981. Redesignated at 46 FR 63203, Dec. 31, 1981]

United States Consumer Grades and Weight Classes for Shell Eggs

§56.216 Grades.

(a) U.S. Grade AA.

(1) U.S. Consumer Grade AA (at origin) shall consist of eggs which are at least 87 

percent AA quality. The maximum tolerance of 13 percent which may be below AA quality may 

consist of A or B quality in any combination, except that within the tolerance for B quality not 

more than 1 percent may be B quality due to air cells over 3/8 inch, blood spots (aggregating not 

more than 1/8 inch in diameter), or serious yolk defects. Not more than 5 percent (7 percent for 

Jumbo size) Checks are permitted and not more than 0.50 percent Leakers, Dirties, or Loss (due 

to meat or blood spots) in any combination, except that such Loss may not exceed 0.30 percent. 

Other types of Loss are not permitted. 
United States Standards, Grades, and Weight Classes for Shell Eggs 

AMS 56 - July 20, 2000 

7

(2) U.S. Consumer Grade AA (destination) shall consist of eggs which are at least 72 

percent AA quality. The remaining tolerance of 28 percent shall consist of at least 10 percent A 

quality and the remainder shall be B quality, except that within the tolerance for B quality not 

more than 1 percent may be B quality due to air cells over 3/8 inch, blood spots (aggregating not 

more than 1/8 inch in diameter), or serious yolk defects. Not more than 7 percent (9 percent for 

Jumbo size) Checks are permitted and not more than 1 percent Leakers, Dirties, or Loss (due to 

meat or blood spots) in any combination, except that such Loss may not exceed 0.30 percent. 

Other types of Loss are not permitted. 

(b) U.S. Grade A.

(1) U.S. Consumer Grade A (at origin) shall consist of eggs which are at least 87 

percent A quality or better. Within the maximum tolerance of 13 percent which may be below A 

quality, not more than 1 percent may be B quality due to air cells over 3/8 inch, blood spots 

(aggregating not more than 1/8 inch in diameter), or serious yolk defects. Not more than 5 

percent (7 percent for Jumbo size) Checks are permitted and not more than 0.50 percent Leakers, 

Dirties, or Loss (due to meat or blood spots) in any combination, except that such Loss may not 

exceed 0.30 percent. Other types of Loss are not permitted. 

(2) U.S. Consumer Grade A (destination) shall consist of eggs which are at least 82 

percent A quality or better. Within the maximum tolerance of 18 percent which may be below A 

quality, not more than 1 percent may be B quality due to air cells over 3/8 inch, blood spots 

(aggregating not more than 1/8 inch in diameter), or serious yolk defects. Not more than 7 

percent (9 percent for Jumbo size) Checks are permitted and not more than 1 percent Leakers, 

Dirties, or Loss (due to meat or blood spots) in any combination, except that such Loss may not 

exceed 0.30 percent. Other types of Loss are not permitted. 

(c) U.S. Grade B.

(1) U.S. Consumer Grade B (at origin) shall consist of eggs which are at least 90 

percent B quality or better, not more than 10 percent may be Checks and not more than 0.50 

percent Leakers, Dirties, or Loss (due to meat or blood spots) in any combination, except that 

such Loss may not exceed 0.30 percent. Other types of Loss are not permitted. 

(2) U.S. Consumer Grade B (destination) shall consist of eggs which are at least 90 

percent B quality or better, not more than 10 percent may be Checks and not more than 1 percent 

Leakers, Dirties, or Loss (due to meat or blood spots) in any combination, except that such Loss 

may not exceed 0.30 percent. Other types of Loss are not permitted. 

(d) Additional tolerances: 

(1) In lots of two or more cases: 

(i) For Grade AA -- No individual case may exceed 10 percent less AA quality eggs 

than the minimum permitted for the lot average. 
United States Standards, Grades, and Weight Classes for Shell Eggs 

AMS 56 - July 20, 2000 

8

(ii) For Grade A -- No individual case may exceed 10 percent less A quality eggs than 

the minimum permitted for the lot average. 

(iii) For Grade B -- No individual case may exceed 10 percent less B quality eggs 

than the minimum permitted for the lot average. 

(2) For Grades AA, A, and B, no lot shall be rejected or downgraded due to the 

quality of a single egg except for Loss other than blood or meat spots. 

[46 FR 39572, Aug. 4, 1981; 46 FR 42441, Aug. 21, 1981. Redesignated at 46 FR 63203, Dec. 31, 1981]

§56.217 Summary of grades.

The summary of U.S. Consumer Grades for Shell Eggs follows as Table I and Table II 

of this section: 

Table I -- Summary of U.S. Consumer Grades for Shell Eggs

U.S. consumer grade 

(origin) Quality required 1 Tolerance permitted 2

Percent Quality 

Grade AA 87 percent AA. Up to 13 .......................... 

Not over 5 ...................... 

A or B. 5

Checks. 6

Grade A 87 percent A or better. Up to 13 .......................... 

Not over 5 ...................... 

B. 5

Checks. 6

Grade B 90 percent B or better. Not over 10 .................... Checks. 

U.S. consumer grade 

(destination) Quality required 1 Tolerance permitted 3

Percent Quality 

Grade AA 72 percent AA. Up to 28 4

 ........................ 

Not over 7 ...................... 

A or B. 5

Checks. 6

Grade A 82 percent A or better. Up to 18 .......................... 

Not over 7 ...................... 

B. 5

Checks. 6

Grade B 90 percent B or better. Not over 10 .................... Checks. 

1

 In lots of two or more cases, see Table II of this section for tolerances for an individual case within a 

lot. 2

 For the U.S. Consumer grades (at origin), a tolerance of 0.50 percent Leakers, Dirties, or Loss (due to 

meat or blood spots) in any combination is permitted, except that such Loss may not exceed 0.30 percent. Other 

types of Loss are not permitted. 3

 For the U.S. Consumer grades (destination), a tolerance of 1 percent Leakers, Dirties, or Loss (due to 

meat or blood spots) in any combination is permitted, except that such Loss may not exceed 0.30 percent. Other 

types of Loss are not permitted. 
United States Standards, Grades, and Weight Classes for Shell Eggs 

AMS 56 - July 20, 2000 

9

4

 For U.S. Grade AA at destination, at least 10 percent must be A quality or better. 5

 For U.S. Grade AA and A at origin and destination within the tolerances permitted for B quality, not 

more than 1 percent may be B quality due to air cells over 3/8 inch, blood spots (aggregating not more than 1/8 inch 

in diameter), or serious yolk defects. 6

 For U.S. Grades AA and A Jumbo size eggs, the tolerance for Checks at origin and destination is 7 

percent and 9 percent, respectively. 

Table II -- Tolerance for Individual Case Within a Lot

U.S. consumer grade Case quality Origin (percent) Destination (percent) 

Grade AA 

AA (min) ....................... 

A or B ............................ 

Check (max) .................. 

77 

13 

10 

62 

28 

10 

Grade A 

A (min) .......................... 

B .................................... 

Check (max) .................. 

77 

13 

10 

72 

18 

10 

Grade B B (min) .......................... 

Check (max) .................. 

80 

20 

80 

20 

[46 FR 39572, Aug. 4, 1981; 46 FR 42441, Aug. 21, 1981. Redesignated at 46 FR 63203, Dec. 31, 1981]

§56.218 Weight classes.

(a) The weight classes for U.S. Consumer Grades for Shell Eggs shall be as indicated 

in Table I of this section and shall apply to all consumer grades. 

Table I -- U.S. Weight Classes for Consumer Grades for Shell Eggs

Size or weight class Minimum net weight per 

dozen (ounces) 

Minimum net weight 30 

per dozen (pounds) 

Minimum net weight for 

individual eggs at rate 

per dozen (ounces) 

Jumbo ............................. 

Extra large ...................... 

Large .............................. 

Medium .......................... 

Small .............................. 

Peewee ........................... 

30 

27 

24 

21 

18 

15 

56 

50 1/2 

45 

39 1/2 

34 

28 

29 

26 

23 

20 

17 

-- 

(b) A lot average tolerance of 3.3 percent for individual eggs in the next lower weight 

class is permitted as long as no individual case within the lot exceeds 5 percent. 

[20 FR 677, Feb. 1, 1955, as amended at 20 FR 10015, Dec. 29, 1955; 32 FR 8233, June 8, 1967. Redesignated at 42 

FR 32514, June 27, 1977, and at 46 FR 63203, Dec. 31, 1981]

U.S. Nest-Run Grade and Weight Classes for Shell Eggs
United States Standards, Grades, and Weight Classes for Shell Eggs 

AMS 56 - July 20, 2000 

10

§56.230 Grade.

"U.S. Nest Run __ % AA Quality" shall consist of eggs of current production of which 

at least 20 percent are AA quality; and the actual percentage of AA quality eggs shall be stated in 

the grade name. Within the maximum of 15 percent which may be below A quality, not more 

than 10 percent may be B quality for shell shape, pronounced ridges or thin spots, interior quality 

(including meat or blood spots), or due to rusty or blackish-appearing cage marks or blood 

stains, not more than 5 percent may have adhering dirt or foreign material on the shell 1/2 inch 

or larger in diameter, not more than 6 percent may be Checks, and not more than 3 percent may 

be Loss. Marks which are slightly gray in appearance and adhering dirt or foreign material on 

the shell less than 1/2 inch in diameter are not considered quality factors. The eggs shall be 

officially graded for all other quality factors. No case may contain less than 75 percent A quality 

and AA quality eggs in any combination. 

[46 FR 39573, Aug. 4, 1981. Redesignated at 46 FR 63203, Dec. 31, 1981, and amended at 60 FR 12401, Mar. 7, 

1995]

§56.231 Summary of grade. 

A summary of the U.S. Nest-Run Grade for Shell Eggs follows in Table I of this 

section: 

Table I -- Summary of U.S. Nest-Run Grade for Shell Eggs

Nest-run grade, description 1 U.S. nest run ___ 

percent AA quality 2

Minimum percentage of quality 

required (lot average) 3

AA quality 4

 20 

A quality or better 5 85 

Maximum percentage tolerance 

permitted (15 percent lot 

average) 3

B quality for shell shape, pronounced ridges or 

thin spots, interior quality (including blood & 

meat spots) or cage marks6

 and blood stains 10 

Checks 6 

Loss 3 

Adhering dirt or foreign material 1/2 inch or 

larger in diameter 5 

1

 Stains (other than rusty or blackish appearing cage marks or blood stains), and adhering dirt and 

foreign material on the shell less than 1/2 inch in diameter shall not be considered as quality factors in determining 

the grade designation. 2 The actual total percentage must be stated in the grade name. 

3

 Substitution of eggs of higher qualities for lower specified qualities is permitted. 4

 No case may contain less than 10 percent AA quality. 
United States Standards, Grades, and Weight Classes for Shell Eggs 

AMS 56 - July 20, 2000 

11

5

 No case may contain less than 75 percent A quality and AA quality eggs in any combination. 

6

 Cage marks which are rusty or blackish in appearance shall be considered as quality factors. Marks 

which are slightly gray in appearance are not considered as quality factors. 

[37 FR 22791, Oct. 25, 1972, as amended at 40 FR 20056, May 8, 1975. Redesignated at 42 FR 32514, June 27, 

1977, and amended at 46 FR 39573, Aug. 4, 1981. Redesignated at 46 FR 63203, Dec. 31, 1981, and amended at 60 

FR 12401, Mar. 7, 1995; 60 FR 13780, Mar. 14, 1995]

§56.232 Weight classes.

The weight classes for the U.S. Nest-Run Grade for Shell Eggs shall be as indicated in 

Table I of this section and shall apply to Nest-Run Grade. 

Table I -- Weight Classes for U.S. Nest Run Grade for Shell Eggs 

Weight classes Minimum average net weight on lot basis 30-dozen 

cases (pounds) 

Class XL ....................................................................... 

Class 1 .......................................................................... 

Class 2 .......................................................................... 

Class 3 .......................................................................... 

Class 4 .......................................................................... 

51 

48 

45 

42 

39 

No individual sample case may vary more than 2 pounds (plus or minus) from the lot 

average. 

[37 FR 22791, Oct. 25, 1972. Redesignated at 42 FR 32514, June 27, 1977, and at 46 FR 63203, Dec. 31, 1981] 
United States Standards, Grades, and Weight Classes for Shell Eggs 

AMS 56 - July 20, 2000 

12

UNITED STATES DEPARTMENT OF AGRICULTURE 

AGRICULTURAL MARKETING SERVICE 

Poultry Programs 

SUMMARY OF U.S. STANDARDS FOR QUALITY OF INDIVIDUAL SHELL EGGS 

Specifications for Each Quality Factor

Quality Factor AA Quality A Quality B Quality 

Shell 

Clean. 

Unbroken. 

Practically normal. 

Clean. 

Unbroken. 

Practically normal. 

Clean to slightly stained.* 

Unbroken. 

Abnormal. 

Air Cell 

1/8 inch or less in 

depth. 

Unlimited movement 

and free or bubbly. 

3/16 inch or less in 

depth. 

Unlimited movement 

and free or bubbly. 

Over 3/16 inch in depth. 

Unlimited movement and 

free or bubbly. 

White 

Clear. 

Firm. 

Clear. 

Reasonably firm. 

Weak and watery. 

Small blood and meat 

spots present.** 

Yolk 

Outline slightly 

defined. 

Practically free from 

defects. 

Outline fairly well 

defined. 

Practically free from 

defects. 

Outline plainly visible. 

Enlarged and flattened. 

Clearly visible germ 

development but not 

blood. 

Other serous defects. 

For eggs with dirty or broken shells, the standards of quality provide two additional qualities. 

They are: 

Dirty Check 

Unbroken. Adhering dirt or foreign material, 

prominent stains, moderate stained areas in 

excess of B quality. 

Broken or cracked shell but membranes intact, 

not leaking.*** 

 * Moderately stained areas permitted (1/32 of surface if localized, or 1/16 if scattered). 

 ** If they are small (aggregating not more than 1/8 inch in diameter). 

*** Leaker has broken or cracked shell membranes, and contents leaking or free to leak.