Cottonseed oil is extracted from the seeds of cotton plant and is mainly a byproduct of cotton production. Cottonseed oil is used as an ingredient in many processed foods like margarine, mayonaise, potato chips, or snacks. There are concerns about its unhealthiness due to the fact that it contains natural toxins and the large amount of pesticides used in cotton plantations. But this is not our topic here.
Our topic is the use of cottonseed oil on Pesach. Cotton seeds are seeds and one might think they are included in the same category as the many seeds we have already discussed. But, cotton seeds themselves are not edible. So most authorities agree that they are not kitniot, as kitniot refer only to edible seeds (OU, Kitniot: a balanced approach, Chabad, R. Kaganoff, Peninei Halacha).
Even if we leave aside edibility and argue that cotton seeds themselves might be kitniot, there is still the fact that cotton plants do not grow in Europe. Cotton was known there in the 13th century as a luxury article imported from the Arabic world, but I doubt the people in Europe had ever seed a cotton plant or the seeds. So one could still argue that cotton seeds most probably were not included in the original decree and then we can certainly be lenient about liquid derivatives (see my comments about oil in the posts on soy, peanuts, sunflowers and Canola oil).
There are still people who avoid cottonseed oil on Pesach. Some probably just do it because they don’t know if it is ok (after all it is cottonseed oil). But there are some sources to cite as well: Minchas Yitzchok (III:138) apparently says that the category of kitniyos includs "any item that is stored the way grain is stored" (R. Kaganoff, Chabad) and "Minchat Chinukh 3:138 is stringent [about cottonseed oil]" (Peninei Halachah).
We found many questionnable items on the kitniot lists, but this time there is a pleasant surprise. None of the lists I usually refert to at this point has cottonseed oil. I have personally never seed cottonseed oil in a store, but if you have – enjoy.
- Danger of chametz traces: No.
- Danger of confusion with chametz (raw): No.
- Danger of confusion with chametz (processed): No.
- Botanical categorization: Malvaceae, flower
- Known in 13th century: Material yes, plant doubtful
- Verdict: Not kitniot.