Detergent fragrance tasting bread
One time I was making a focaccia and instead of spraying a water mist in the oven I accidentally sprayed kitchen cleaner in the very hot oven! This did not go well. I got a face full of super-heated kitchen cleaner and the bread smelled and tasted of chemicals so I had to throw it away.
I doubt very much that this is the case with your friend's bread though. Most likely the taste is from an ingredient in the bread that has a strong flavor. Spices like aniseed, fennel, cardamom, or herbs like lavender are very aromatic and add strong flavors as well which some would say are very chemical-like. Some people like this, some people do not and it's fair to say you are one of the latter. Those ingredients are safe to eat, just not to your taste.
A test of whether it is an ingredient or an actual cleaning product causing the smell and taste would be to pull a bit of the bread from the center and taste it in isolation. Take your sample to a different room away from the other bread to test it. If your sample tastes like detergent it's in the ingredients, if the smell and taste is only on the outside of the bread or close to the surface then it's likely actual chemicals.