It depends. If the jar is made of BPA-free plastic that does not contain any harmful substance, then you can reuse it. Also, it should be dishwasher safe; thus, you can wash it as much as you like and reuse it. However, glass is the ideal choice in this situation since the construction process of glass doesn’t involve any harmful chemicals whatsoever. But most of the good-quality plastic containers are BPA-free, and you won’t have any issue finding them.