ChaNaN does not apply to a davar heter. This is because chatichah na’ases neveila, as it name implies, means that the entire item that absorbed ta’am of issur becomes like a neveila. Since one must refrain from eating the item, we view it as becoming 100% assur. This sevara obviously does not apply to a davar heter such as kosher milk, kosher meat or kosher fish. Therefore, if 1 gallon of kosher milk is mixed with 10 gallons of water, and this mixture is then mixed into 100 gallons of water, we would not say ChaNaN and the milk would be batel b’shishim. Although, we would still insist on labeling this product as dairy, however there would be no need to kasher the equipment that came in contact with the mixture since the milk is already batel.
Chalav stam
Although chalav akum is issur and the halachos of ChaNaN should apply, nevertheless the Pri Migadim (Y.D. S.D. 97:1) proves that b’zman ha’zeh, we do not say ChaNaN by chalav akum, at the very least when it is mixed lach b’lach. Therefore, how much more so we would not apply ChaNaN today to chalav stam, even if one is makpid on chalav Yisroel, since one can be mitztaref the heter of Rav Moshe zt”l as well.
Chametz
There is a machlokes Rishonim as to whether chametz before Pesach is considered heter or issur. This has numerous nafka minos, and Shulchan Aruch in some instances paskens l’chumra and in others paskens l’kula. However, Magen Avrohom (447:38) rules that regarding whether we say ChaNaN on chametz before Pesach, we rule leniently like the opinions that chametz is a davar heter. Therefore, if a seasoning containing 5% chametz was mixed into a soup before Pesach, it would be sufficient if the soup contained 60 times the chametz component. It would not need to be 60 times the entire seasoning.
Issur mashehu that is not batel
Midi’oraisa ChaNaN only applies to basar b’chalav. When meat is cooked with milk the entire ta’aruvos becomes 100% assur. Midi’rabannan we extend the halachos of ChaNaN to all other issurim as well. However, Rabbeinu Tam says that we do not extend ChaNaN b’shar issur to an issur ma’shehu since by basar b’chalav, which is the source of the issur, we would not say ChaNaN if the milk or meat was batel b’shishim.
Similarly the Pri Migadim (M.Z. 100:1 and 69:19) says that we would do not say ChaNaN by issur chazusa (colorant) or ma’amid that are batel b’shishim, since these issurim do not apply to basar b’chalav. Although in all these cases the product would be assur, the kailim would not be affected because the ta’am of the issur is batel. An avida l’taima is more complicated. Although we would not say ChaNaN if the issur is less than shishim, still since the ta’am is not batel, the kailim would need to be kashered.
Melach ha’baluah m’dom
Shulchan Aruch (Y.D. 105:14) teaches that melach (or any other kosher avida l’taima ingredient) that is boleyah non-kosher, will still be batul b’shishim, even though the ta’am of the salt is not batel. This is because, as Rema explains, אין הנאסר אוסר יותר מן האוסרו, the product does not become more chamur than the issur that made it assur. Although ChaNaN has us view the entire mixture as issur, nevertheless we only view the mixture as having the properties of the original issur. If the original issur can be batel b’shishim, the mixture can be batel b’shishim as well. Therefore, although we view flavors as an avida l’taima, still if the flavor components are comprised of inherently kosher ingredients, even though the flavor contains non-kosher carriers and diluents, or was processed on non-kosher kailim, it would still be batel b’shishim.