ATLANTA — ATLANTA—Complaints about empty space in packages of food have long been the subject of consumer complaints, but manufacturers say there’s often a good reason for it.

The Food and Drug Administration calls it “slack-fill.” Excessive amounts of empty space could be a problem, but the FDA says it’s ok if the “slack-fill” serves a purpose.

Here’s why you might find dead air in your bag of chips.

Dondre Anderson of Symphony Potato Chips in Atlanta tells us a little air space is necessary for a couple of reasons. No one has ever complained about the packaging of his product or the amount of food inside, but he’s heard the complaints about others.

A blast of nitrogen surrounds his chips to keep them fresh and extend their shelf life.

“It keeps the product fresh while it sits in the bag,” says Anderson. “The shelf life lasts four to six months.”

It also serves as a bodyguard while the chips are shipped to stores.

“I don’t want to be able to crush the chips,” says Anderson. “Nobody likes crushed chips.”

The FDA says products like chips or cereal may settle during shipping. Some boxes and bags are larger than the amount of food inside to accommodate all of the labeling required.

“The FDA has not defined an acceptable amount of slack-fill but may consider a package misleading if the slack-fill is non-functional,” says Deborah Kotz of the FDA.

While Symphony Chips seems to have found the right balance, “slack-fill” is something the FDA monitors to look for cases where it might be excessive and misleading.