The Basis for the Prohibition Against Leaving Eggs Overnight

I have heard that one may not leave eggs overnight. What is the basis for this?

The Gemara (Nida 17a) writes that there is a sakana (danger) to eat peeled eggs, onions and garlic that were left overnight. According to many opinions, the sakana applies to both liquid and boiled eggs. The sakana only applies if the shell was completely removed, but if one piece of shell remains on the egg then there is no sakana.

To avoid this sakana, the egg may be mixed with other ingredients such as salt or oil. Igros Moshe (Y.D.  III: 20) writes that industrial liquid eggs which are produced in one factory with the intent of shipping them to bakeries all of over the country, such that they cannot possibly be used the same day that they were cracked, are not subject to this sakana.

The Gerald & Karin Feldhamer OU Kosher Halacha Yomis is dedicated to the memory of Rav Yisroel Belsky, zt”l, who served as halachic consultant for OU Kosher for more than 28 years; many of the responses in Halacha Yomis are based on the rulings of Rabbi Belsky. Subscribe to the Halacha Yomis daily email here.