A question: How come all the bottles of mustard oil in Indian groceries have labels that say, "For Massage Use Only. Do Not Take Internally." Is this a warning I should heed? Is there something toxic about mustard oil? If so, why do none of the Indian cookbooks--which sent me to the market in search of mustard oil in the first place--warn me about it? Is it a purity issue: are there certain mustard oils not refined enough--or refined too much--for cooking? If so, are there pure mustard oils designed spcifically for cooking? I've seen some bottles labeled "mustard-flavored oil" that proclaim they're suitable for cooking, but they seem to be mostly made of soybean oil. Is this what I want? What's going on here? Should I take up massage and forget about teaching myself to cook Bengali food?
Below is a link to the FDA alert on mustard oil. From the looks of the alert, there are two types of mustard oil. One, (which is adulterated with erucic acid) causes "nutritional deficiencies and cardiac lesions in test animals"; the other is safe for cooking.
But, I'll let you read the entire alert. Maybe you can figure out which one is on the shelves of your grocery.