The APA and an agency’s enabling legislation provide a formal process for promulgation regulations to ensure that there is public notice of proposed regulations and a chance for public comment before the regulation is finalized (notice- and- comment rule making). Properly promulgated regulations have the same force as a law passed by Congress. For example, its enabling legislation may direct the FDA to prevent the sale of food packed under insanitary conditions. The agency must define insanitary in such a way as to carry out the wishes of Congress, while recognizing the realities of food production and handling.

One such rule could define how many insect parts are allowed in a pound of butter. The FDA must first publish its proposed regulation in the Federal Register, which is a compilation of the federal notices and proposed and final rules by agencies. This notice could exceed 100 pages. All interested persons, which might include butter and cookie makers, are given a period to comment on the rule. If the proposed rule allows three insect parts per pound, the butter industry might complain that reducing insect parts to less than twenty per pound would increase the cost of butter. A public interest group might comment that there should be no insect parts in butter and, if there are, they should appear on the label so consumers know what they are buying.

The FDA must the review the responses to the proposed regulation, and in some cases must hold public hearings to get more input. It then decides whether it wants to change the standard. In this case, assume it decides to raise the level to five parts per pound. It then publishes in the Federal Register a final rule with this standard. The final rule will include a summary of the comments the FDA received and explanations why it did or did not follow them. In this case it would say that it was persuaded that three would be too expensive, but that twenty was too many and indicated filthy conditions. It also would say that it is too expensive to ban insect parts, and because they do not carry disease, putting insect parts on the label would give consumers the wrong impression that the butter was unsafe.

When the final rule goes into effect, it is published as part of a series of books called the Code of Federal Regulations (CFR). A food manufacturer who wants to start producing butter could look in the Title 21 of the CFR, where the FDA regulations are codified. Agencies also can publish informal guides for the industries they regulate. Although these do not have same legal standing as regulations that were subject to notice-and- comment in the Federal Register, they are very useful guides to agency practice. The FDA publishes both formal regulations and more informal guidelines to help industry comply with its requirements.