Comparison · Standards and regulation
What is the difference between a Class A and a Class B egg?
A Class A egg must meet, all at once, the five requirements of RIISPOA (art. 225): a normal, smooth, clean and intact shell, an air cell up to 6 mm high and stationary, a yolk visible only as a shadow, a clear white, and a germ spot with imperceptible development. A Class B egg is the harmless egg that does not meet Class A (art. 226), and it goes exclusively to industrial processing.
Updated · 5 min read
What is the difference between Class A and Class B under RIISPOA?
Class A is the most demanding class: the egg must meet the five requirements of art. 225 at the same time. Class B is defined by what is left over: it is the harmless egg that does not fall into Class A (art. 226, I), and it includes eggs with a few small blood spots in the white and yolk (art. 226, II).
The table sets the criteria side by side, using the text of articles 225 and 226. The Class B column shows what the rule says, and for many criteria it sets no limit of its own: Class B is defined by exclusion.
| Criterion | Class A (art. 225) | Class B (art. 226) |
|---|---|---|
| Definition | Meets the five requirements at the same time | Harmless egg that does not fall into Class A (item I) |
| Shell and cuticle | Normal shape, smooth, clean and intact (item I) | No separate requirement in the text |
| Air cell | Up to 6 mm and stationary (item II) | No separate limit in the text |
| Yolk | Visible on candling only as a shadow (item III) | No separate requirement in the text |
| White | Clear, translucent, consistent, free of spots or cloudiness (item IV) | No separate requirement in the text |
| Germ spot | Imperceptible development (item V) | No separate requirement in the text |
| Blood spots | No spots in the white (item IV) | Small and few, in the white and yolk (item II) |
| Destination | Classified for human consumption (art. 224) | Exclusively industrial processing (sole paragraph) |
An egg that fails one Class A item can only be Class B if it is harmless (art. 226, I). A cracked egg has its own destination under art. 227, so it is not treated simply as Class B: see cracked eggs.
How does the EU standard define Class A compared with Brazil?
The EU Class A is set out in Article 3(1), with seven points. It covers what RIISPOA covers, but with differences in wording and in items: the EU standard names foreign matter and foreign smell as items of their own, and the Brazilian art. 225 does not list them that way.
Three differences deserve attention. The Brazilian rule requires a smooth shell, and the EU text quoted here does not mention texture. The Brazilian yolk must show an apparent outline, while the EU yolk must have no clearly discernible outline. The EU standard also provides for the 'extra' class, with an air cell of up to 4 mm, which the RIISPOA text quoted here does not contain.
| Item | Brazil (RIISPOA, art. 225) | EU (Article 3(1)) |
|---|---|---|
| Shell and cuticle | Normal shape, smooth, clean and intact (item I) | Normal shape, clean and undamaged (point a) |
| Air cell | Up to 6 mm and stationary (item II) | Up to 6 mm and stationary; up to 4 mm for the 'extra' class (point b) |
| Yolk | Only as a shadow, with an apparent outline, moving slightly and returning to centre (item III) | Only as a shadow, without a clearly discernible outline, moving slightly and returning to centre (point c) |
| White | Clear, translucent, consistent, free of spots or cloudiness, chalazae intact (item IV) | Clear and translucent (point d) |
| Germ spot | Imperceptible development (item V) | Imperceptible development (point e) |
| Foreign matter | No separate item; a clean shell (item I) is the criterion | Not permissible (point f) |
| Foreign smell | No separate item; art. 500, V covers contact with substances that transmit odours | Unintended foreign smell is not permissible (point g) |
In practice, the difference in wording matters less than the inspection method: yolk, air cell and white depend on interior examination under both texts. For each RIISPOA item, see Brazil's Category A requirements.
What happens to an egg that no longer meets Class A?
In the European Union the rule is direct: a Class A egg that no longer has the characteristics of Article 3(1) must be downgraded to Class B (Article 3(2)). The same article says that eggs not marked within 10 days after laying are Class B.
In Brazil, the RIISPOA text gathered here does not cover downgrading. The topic is explained in the Category B guide. A clean cracked egg with an intact shell membrane follows art. 227 instead: it goes to industrial processing as quickly as possible.
Does washing an egg still allow it to be classed as Class A?
In the European Union, no: a Class A egg may not be washed or cleaned, before or after grading (Article 4(1)), except as provided for in paragraph 3 of the same article.
In Brazil, washing has its own rules, covered in egg washing rules. This is one of the points where the two standards do not match.
How does a line separate Class A from Class B in practice?
Separation combines two kinds of examination. The shell and external dirt are seen on the surface, and interior items need candling. The split below is practical judgement, not wording from the rule:
- Shell, shape and cleanliness: surface inspection, with candling for fine cracks (art. 225, I).
- Air cell, yolk, white and germ spot: candling only (art. 225, items II to V).
- Blood spots inside the egg, in the white and yolk: candling, because they do not show on the shell (art. 226, II).
- Foreign smell: no visual check shows it, and it depends on origin and storage.
A surface camera covers the shell and dirt, but not the interior criteria. For the difference between the methods, see candling or computer vision.
Frequently asked questions
Can a Class A egg be downgraded to Class B?
- In the European Union, yes, and it is mandatory: a Class A egg that no longer meets Article 3(1) must be downgraded to Class B (Article 3(2)). In Brazil, the case is explained in the Class B guide, together with the RIISPOA text that covers it.
Is the EU standard stricter than the Brazilian one?
- There is no single answer. The two standards have different items: the EU lists seven points and an extra class with an air cell of up to 4 mm, while Brazil requires a smooth shell and a yolk with an apparent outline. Each item should be read in the text of the standard that applies to your market.
Which Class A items can only candling check?
- Under items II to V of art. 225, the air cell, yolk, white and germ spot can only be assessed by candling. Blood spots in the white and yolk also sit inside the egg. The shell and external dirt can be seen on the surface, but fine cracks need candling.
Sources
- Decreto nº 9.013/2017 (RIISPOA), Presidência da República (Brasil)
- Delegated Regulation (EU) 2023/2465, marketing standards for eggs, EUR-Lex
How Vigiovo helps
Vigiovo grades eggs on the conveyor as clean, dirty, cracked or unverified, in real time, with deterministic computer vision: every decision comes with the measurements behind it, on an ordinary CPU.