The safety of children in cars brings new meaning to the term "precious cargo." Perhaps that's why so many parents were concerned when Consumer Reports published the disturbing results of its crash test ratings for infant car seats. Then, almost as quickly as the report was released, the group withdrew it, stating it suspected a problem with the crash tests.

Suddenly, there were questions: Were the car seats safe or not? Edmunds explains.

At some point, NHTSA does expect to have a side-impact test for child safety seats, but not until crash-test-dummy technology will support it.

At some point, NHTSA does expect to have a side-impact test for child safety seats, but not until crash-test-dummy technology will support it.

Consumers Union tests

Consumers Union (CU), a group that publishes its product tests in Consumer Reports magazine and on its Web site, tested 12 rear-facing infant car seats that snap into bases. The group hired an outside laboratory to perform the tests because it doesn't have its own crash test facility for measuring car seat safety.

The group's goal was to test infant seats more rigorously than federal safety standards require. Its thinking was that car seats should be tested at the same crash test speeds as vehicles. Car seats are currently tested to simulate crashes at 30 mph, while vehicles are generally tested for front impacts at 35 mph and side impacts at 38 mph.

To arrive at its results, Consumers Union tested multiple units of each car seat, securing the bases with vehicle safety belts in some instances and with the LATCH (lower anchors and tethers for children) system in others. It used crash test dummies weighing the maximum weight each car seat could hold — 30 pounds for one seat and 22 pounds for all the others. The crash test was designed to simulate a collision in a Ford Explorer in a 35-mph front-impact and a 38-mph side-impact crash, the speeds used for the government's New Car Assessment Program, or NCAP.

In the front-impact test, seven of the 12 car seats failed. CU reported that these seats separated from their bases, rotated too far or would have resulted in grave injuries to the child based on the measurements of impact recorded by the test dummy. When the group retested all the seats at the lower 30-mph federal standard, the crash test results changed: All passed except one.

In the side-impact test, eight models failed, with four separating from their bases. Since there currently is no federal standard for car seats in side-impact collisions, Consumers Union did not perform any additional tests.

What went wrong?

Because so many seats performed so poorly, Consumers Union met with the National Highway Traffic Safety Administration (NHTSA), the federal agency responsible for ensuring that cars and car seats meet the U.S. standards, to share its findings. NHTSA officials requested copies of the test data, which Consumers Union provided. It published its findings a few days after meeting with NHTSA.

As NHTSA analyzed the data Consumers Union had provided, it suspected that the side-impact tests had been performed at a speed much higher than 38 mph.

"The organization's data show its side-impact tests were actually conducted under conditions that would represent being struck in excess of 70 mph, twice as fast as the group claimed," said NHTSA Administrator Nicole Nason in an official statement.

NHTSA used its own testing facilities to conduct new side-impact tests on 11 of the 12 seats that Consumers Union tested. All the seats stayed in their bases. It videotaped the tests for each seat, making them available on its Web site.

After some dialogue between NHTSA and Consumers Union, CU decided to retract its original report and ratings recommendations and launch a new test immediately. In its statement withdrawing the report, Consumers Union noted that it agreed that the side-impact tests simulated a crash more severe than 38 mph.

Are the federal tests good enough?

Regardless of the results of the Consumers Union tests, the group raised awareness that the government tests car seats at a lower speed than it tests vehicles. To meet federal safety standards, a car seat is strapped to the center of a bench seat, which is then projected rearward to simulate a frontal crash of 30 mph. The test is conducted twice: one with the seat secured by a lap belt, and again using LATCH. And unlike vehicle crash tests, which receive a rating of one to five stars, car seats receive only a pass or fail grade. The government does not yet test car seats for side-impact crash performance.

In its test report CU stated, "Our new tests are tougher than the federal car-seat standard because a significant performance gap exists between vehicles and the car seats they carry. "NHTSA, however, said this isn't true. "The 30-mph test that car seats are subjected to is more severe than the 35-mph frontal impact vehicle test because of the acceleration rate," said NHTSA Spokesperson Rae Tyson.

Car seats are not currently tested for performance in a side-impact crash test. In 2002, however, NHTSA analyzed how two car seats performed, one convertible seat and one rear-facing infant seat, in side-impact tests of eight vehicles, as an experiment to see if side-impact data could be successfully obtained. The results were inconclusive, in large part because the child-size test dummies that currently exist are designed to measure injuries caused by frontal impacts. (See "Meet the Family of Crash-Test Dummies.") At some point, NHTSA does expect to have a side-impact test for child safety seats, but not until crash-test-dummy technology will support it.

Are infants really at risk?

While Consumer Reports' initial study caused significant concern, it's important to understand the real-world risks to infants. Children riding in rear-facing infant seats have the lowest risk of injury among all children in vehicle crashes, according to Partners for Child Passenger Safety (PCPS), which conducts the world's largest study of children involved in real-world crashes. According to the group's study of crashes from 2005, just 3.1 percent of infants involved in crashes were injured. Infants' low risk is due to several factors, including where they sit in the vehicle and the way they are restrained.

Nissan 370Z
(Courtesy of PCPS)

Further, side-impact injuries occur less frequently than other types of injuries.

Nissan 370Z
(Courtesy of PCPS)

According to PCPS's 2005 study, less than 1 percent of the crashes reported to the group involved infants in rear-facing seats in side-impact crashes. And of those side-impact crashes, the risk of injury was less than half of 1 percent.

"It's important to place findings such as those reported initially in Consumer Reports in perspective," said Kristy Arbogast, direct of field engineering at PCPS. "Children riding in the correct restraint for their age and size are far safer than if they were not restrained at all, or in a restraint inappropriate for their age or size."