Explainer · Defects and grading
Cloudy or stained egg white: can the egg still be Class A?
For Class A, the white must be clear and translucent, consistent, free of stains or cloudiness, with the chalazae intact (RIISPOA, art. 225, IV). A cloudy or stained white takes the egg out of Class A. Because the white is inside the egg, it is checked by candling, and a surface camera cannot assess it.
Updated · 4 min read
What does Class A require of the white?
Class A requires the white to be "clear and translucent, consistent, free of stains or cloudiness and with the chalazae intact" (RIISPOA, art. 225, IV). Each term has a role: clear and translucent describe the appearance, consistent describes the texture, and the absence of stains and cloudiness rules out the most visible defects.
The chalazae are the cords of white that hold the yolk in the centre of the egg. The rule requires them to be intact. Because they sit inside the shell, this is one more item that only an internal inspection can confirm.
Cloudy or stained white: when does the egg leave Class A?
Whenever the white is cloudy or stained, the egg does not meet art. 225, IV, and cannot be Class A. The rule allows no degree of cloudiness: any cloudiness or stain falls under the test.
Blood stains deserve separate attention. Under RIISPOA, small blood stains, few in number and present in the white and the yolk, put the egg in Class B (art. 226, II). If the blood also reaches the white, or there are dark stains, the egg is unfit for human consumption (art. 500, I). Cases of staining are covered in blood spots in eggs.
| State of the white | Destination under RIISPOA |
|---|---|
| Clear, translucent, free of stains, chalazae intact | Can be Class A if it meets the other requirements (art. 225) |
| Cloudy, no blood, and harmless | Not Class A; can be Class B (art. 226, I) |
| Small blood spots, few, in the white and the yolk | Class B (art. 226, II) |
| Dark stains or blood also reaching the white | Unfit for human consumption (art. 500, I) |
Why is the white only assessed by candling?
The white sits inside the shell, and a surface camera only sees the outside. That is why the white is checked by candling, a mandatory step in registered establishments (RIISPOA, art. 223, II). In candling, the egg is examined against a bright light, and the white shows up clear or cloudy.
Vigiovo grades by the shell: dirt, shape and visible cracks. It does not assess the white, the chalazae or internal stains, which is outside what a camera can see. Candling therefore stays necessary at this point. The comparison of methods is in candling vs computer vision, and the air cell, another internal item, is covered in the egg air cell.
How is the white treated in the European Union?
The European regulation uses similar terms. For Class A, the white must be clear and translucent (Delegated Regulation (EU) 2023/2465, art. 3(1)(d)). The European text does not list the chalazae, so the requirement for intact chalazae comes from RIISPOA.
A Class A egg that no longer has these characteristics is downgraded to Class B (art. 3(2)). The logic is the same in both texts: the egg stays Class A only while it meets the internal requirements. To see how Vigiovo grades eggs, see how it works.
Frequently asked questions
Does blood in the white take an egg out of Class A?
- Yes. Class A requires a white free of stains (RIISPOA, art. 225, IV). A few small blood spots, present in the white and the yolk, put the egg in Class B (art. 226, II). If blood also reaches the white, or there are dark stains, the egg is unfit for human consumption (art. 500, I).
Can a cloudy white be Class B?
- Under the rule, yes, if the egg is harmless and does not fall under Class A (RIISPOA, art. 226, I). Class B eggs are intended exclusively for industrial processing (art. 226, sole paragraph). Cloudiness alone rules out Class A.
Can the Vigiovo camera check the white?
- No. Vigiovo grades by the shell, with dirt, shape and visible cracks, and does not assess the white, the chalazae or internal stains. These are checked by candling, a mandatory step in registered establishments (RIISPOA, art. 223, II).
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.