>We have already plenty of certification companies that take your money in exchange for a nice logo/label on the packaging. You still need an expert to tells if they do it right.
I think you're underestimating how reputation and communication lead to consumers gaining reliable information in the marketplace. Apple didn't develop a reputation for quality and customer service for nothing. It earned that reputation, and the marker rewarded it for it. Consumer knowledge is often times far more sophisticated than voter knowledge. If consumers are too ignorant to solve this problem, then I have no faith voters will solve it. This comes down to a problem of ignorance, and once that problem is solved, then marketplace solutions can be introduced, whether through cookie-cutter mandates imposed by government that reduce our freedom, or through a diverse array of products/services provided by entrepreneurs that expand our options.
This idea that since you need an expert, it must be done through regulations imposed on everyone, is nonsensical. Experts can work for nongovernmental organizations too, and can have a contractual obligation to serve the public interest, just as government officials do. Moreover, the government can appoint experts to the task, and provide its own certification of what products meet its standards, without making said standards mandatory.
Frankly I find this insistence that only a government appointed body, that imposes standards that no one in society is allowed to opt out of (even if they like BPA in their food), would work, because of an almost religious like faith that market mechanisms, meaning people interacting through voluntary exchanges and contracts, can't work, to be immature.
Assuming no pollution-related concerns affecting non-participants, there is absolutely no moral justification for prohibiting people from buying/selling food containing some hormone disrupting chemical. What society needs is the information with which to make informed decisions. But that decision should be each individual's to make.