What does it mean to under-fill a consumer product package? We’ve all opened boxes and bags that seemed more full before we saw what was inside, or a few tiny over-the-counter pills in a bottle stuffed with cotton. When is this considered “misleading,” and when is it just a normal thing that protects products?

Regular readers are familiar with the Grocery Shrink Ray, where the amount of product in a package shrinks over time to keep the price of a product consistent without decreasing profits. Traces of the Shrink Ray are everywhere: even people who aren’t aware of the phenomenon notice the standard 1.5 quart ice cream containers and 59-ounce orange juice bottles that were once half gallons.

Yet sometimes a manufacturer builds extra space into packaging to protect the merchandise inside, to make a product look more plentiful than it really is, or to make a product take up more space so it’s easier to notice or harder to steal. This space is called slack fill: the difference between a container and the product that fills it.

While the Food and Drug Administration has regulations on the books that ban companies from building excessive slack fill into merchandise, it couldn’t point our colleagues to any nationwide cases that they’ve actually pursued recently. California has stricter laws. Well, it did: in 2013, the governor signed a bill that changed how existing packaging laws are enforced, strengthening exemptions to the law. That may decrease cases against companies going forward… as long as companies are able to provide an excuse that fits the law.

The Golden State’s consumer protection laws ban non-functional slack fill or “empty space in a package for no reason,” but the difference has been that district attorneys there have been enforcing the statutes. One prosecutor told our colleagues at Consumer Reports that there have been 27 cases settled against companies selling consumer packaged goods in the last six years.

For example, you might remember a lawsuit settlement earlier this year where Procter & Gamble settled with the state of California over slack fill in cosmetic products, and CVS had settled for similar store-brand products before that.

It’s non-functional slack fill that’s against the law, though, and companies will try to find a way to argue that the excess packaging is functional. Sometimes they’re correct. A microwaveable instant pasta package might be larger than its contents to keep the noodles inside from boiling over, for example. Pharmaceutical companies trie to argue that their products need to be in larger bottles or boxes to accommodate required patient information on the package. That’s why bottles of medicine or supplements sometimes come with more cotton than product in them.

When you notice slack fill that seems excessive and serves no obvious purpose, consider making a complaint to the Food and Drug Administration, or to your state’s attorney general. They aren’t able to check every product on the shelves, and depend on complaints from the consumers who are on the ground, using these products.

Sometimes competitors speak up, too, like Watkins, a company that decided that under-filling of 8-ounce-size boxes with 6 ounces of pepper by giant competitor McCormick could not stand.

Otherwise, we’ll all have to depend on crusading prosecutors or annoyed consumers with money to file a class action lawsuit to keep the marketplace free from slack fill. The latter does happen: there’s currently a lawsuit against Motrin filed in federal court by plaintiffs from multiple states for its large packaging compared to the relatively tiny amount of space that its pills take up in the package.

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