Costco's Kirkland Pacs top Tide Pods in our detergent tests

For as long as we've been testing laundry detergent pods—those convenient, single-use packets—only Tide Pods have cleaned well enough to make our winner's list. But there's a new top pod in our tests of laundry detergents, and it costs about 30 percent less than Tide Pods. The only catch is you'll need a Costco membership to find it. And if you have kids at home, special safety precautions are a must.

Kirkland Signature Ultra Clean Pacs, sold exclusively at Costco, scored two points higher than Tide Pods to become our top-rated laundry detergent pod. Both products were very good at tackling grass and ring-around-the-collar in our tough tests, though only the Kirkland was good at removing blood. And Kirkland costs a competitive 14 cents per load, compared with 22 cents per load for the Tide Pods.

The other nine laundry detergent pods in our latest tests didn't do as well. Worst of the bunch was Seventh Generation Natural Laundry Packs Advanced Triple Enzyme, which costs 30 cents per load and managed an overall score of just 35 out of a possible 100.

While the Kirkland Signature Ultra Clean Pacs earn our praise for price and performance, we do have concerns about its packaging. As we've reported over the last year, detergent pods pose a serious safety risk to children, who might mistake the colorful, bite-sized capsules for candy. Since pods became commonplace in early 2012, there have been more than 9,000 incidents of exposure involving children age 5 or younger.

Consumer Reports has called on the industry to develop more child-resistant packaging. Procter & Gamble, maker of Tide, responded by adding safety latches to its plastic containers and making the transition from transparent to opaque plastic. The grape-colored Kirkland pods, however, are packaged in a see-through plastic tub not unlike the containers pretzels and other snacks come in. And small fingers will have no trouble removing the flimsy plastic lid.

And so, while Kirkland Signature Ultra Clean Pacs is tops for cleaning, Costco should insist on more child resistant packaging. If you have or care for young children, keep all detergents out of their reach. And if a child does ingest a pod, call the poison-control helpline immediately (800-222-1222).

—Daniel DiClerico