Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Horrible and pervasive chemical odor

It is pretty hard to criticize a fitness ball. I have seen this brand at several gyms and the quality seems durable enough. Unfortunately, the ball has such a pervasive and intense odor that it is impossible to keep in your home. I truly can't emphasize this enough. After putting it in the closet, the smell transferred to all of my clothes. Finally, I put it in the hallway of my building (a small 3 story Victorian). Even after a week, the *entire* building smells like this weird chemical odor. And the halls are wide and airy (with no heat). I cringe at the thought of actually bumping into one of my neighbors. I have held off returning this in the hopes that the ball would air out. But no such luck. Returning these items is always a drag, and it is hard not to be just a little resentful at the lack of quality control.