George, it may be worth having a look on Wikipedia or similar. I think there was an experiment years ago that showed that Mustard oil had a negative effect on rats.
I think it was later established that humans don't suffer from the same ill effects.
You cannot by law buy mustard oil for human consumption in the EU, USA, Canada, Australia etc, so you will never see a bottle labled for consumption in these zones.
I've got the KTC pure mustard oil and I'm not at all worried that it will harm me.
Paul.