They may be based on empty air, but slack fill lawsuits are filling up the courts, with new cases challenging everything from dish soap to potato chips to coffee drinks.

Alleging The Honest Co. was less than truthful, Chelsea Grey filed suit in California federal court over the ten percent difference in dish soap found in the company's packaging as compared to the label statement.

Although the bottles state they contain 26.5 fluid ounces, the Wall Street Journal reported in March that the bottles actually contain just 24 fluid ounces, according to the complaint. Spokeswoman for the company tolf the publication that "[t]he company is rolling out new dish soap in revised packaging with labels stating the bottles contain 24-fluid ounce[s] … to eliminate a small inconsistency between physical fill volume and labeled fill volume."

Grey seeks to certify a nationwide class of consumers who purchased the allegedly underfilled containers over the last several years at "a price premium," as well as a corrective advertising campaign, and compensatory, statutory and punitive damages.

Similar allegations were levied against Wise Foods Inc. regarding the company's potato chips. A pair of consumers asserted that the company uses larger bags with more slack fill than competitors to trick consumers into thinking they are getting more than they actually are.

Just one-third of the space available in the Wise bags is actually used, the New York federal court complaint stated, with slack fill accounting for between 58 to 75 percent of its products. Even recognizing the need for some slack fill, a sizable percentage is nonfunctional, the plaintiffs told the court, as demonstrated by the fact that Wise products have "significantly greater" slack fill than the packaging of competitors, even those using smaller product bags.

"The real explanation lies in Defendant's desire to mislead consumers about how much product they are actually purchasing and thus increase sales and profits," according to the complaint. "The packaging of the Products is uniformly made out of non-transparent wrappings so that consumers cannot see the slack-fill therein, thus giving Plaintiffs and the Class the false impression that there are more chips inside than there actually is."

In addition to injunctive relief, the suit seeks compensatory and punitive damages.

And in Oregon federal court, J. Podawiltz claimed that, "[l]ike its eponymous name, Rockstar Inc. thinks it can get away with anything," including cheating purchasers out of six percent of the advertised volume of its energy coffee drinks. Despite the label's stated 473 mL of beverage, the defendant's cans were short about 30 mL, the plaintiff claimed, as revealed in a recent study by a food laboratory that discovered the discrepancy on Rockstar products while finding that similar drinks from Starbucks and Monster contained the amount of beverage advertised on their cans.

Requesting an injunction to stop the alleged volume misrepresentations (for a class of Oregon consumers dating back to March 26, 2016), Podawiltz also seeks actual damages or $200 statutory damages under the state's consumer protection law, as well as punitive damages.

To read the complaint in Grey v. The Honest Company, click here.

To read the complaint in ALCE v. Wise Foods, Inc., click here.

To read the complaint in Podawiltz v. Rockstar, Inc., click here.

Why it matters: As demonstrated by the lawsuits filed in states across the country against a range of different products—from dish soap to potato chips to energy coffee drinks—slack fill litigation continues to fill the courts.