Update (2/11/2011): This story was updated to include information from Environmental Health & Engineering, the company that conducted the tests for the new CPSC report.

The Consumer Product Safety Commission and the U.S. Army released a long-awaited report Thursday about a rash of unexplained infant deaths at Fort Bragg, N.C., concluding that no environmental issue—including contaminated drywall—was to blame for the babies’ deaths.

But three experts who reviewed the report for the Herald-Tribune and ProPublica said the tests used to examine the drywall were unreliable and incomplete—and that more tests should have been done.

At least nine infants have died of unknown causes at Fort Bragg since 2007, including three infants of different parents who lived in a single house.

In Spring 2010, Army criminal investigators who probed one baby’s death noticed corrosion and other signs that can point to problematic drywall—most of it imported from China during the housing boom—and ordered that a sample from the infant’s room be tested.

The results from a laboratory chamber test revealed high levels of two sulfur gases associated with contaminated drywall—levels that exceeded a known sample of tainted Chinese board used for comparison and that were 14 to 18 times greater than an untainted control sample. Many experts consider the chamber test the most definitive for tainted drywall.

“The only test result I’ll accept is a chamber test,” said Michael Foreman, head of Foreman & Associates, which has been investigating tainted drywall since the crisis emerged more than two years ago. “It’s the only one that measures off-gassing. That’s the only thing that matters when we’re talking about tainted drywall.”

Foreman is a member of the American Society for Testing and Materials committee that is studying the drywall problem.

After the Army received the test results, the family was told to leave their home, and Fort Bragg’s commanders ordered additional tests. Instead of chamber tests, however, the new tests measured certain elements within the drywall. Based on those results, the Army announced that the drywall was not problematic.

The report that the CPSC and Army released Thursday reinforced that finding. It said that the homes didn’t have tainted drywall or any other environmental problem.

But the new report relied on the same questionable methods that were used in the Army’s second round of tests. The findings also are at odds with a report produced by one of the CPSC’s own inspectors, who was sent to Fort Bragg to examine the two homes last year. Based on the chamber test, and on corrosion, failing electronics and health symptoms described by the families, he reported that the homes contained signs consistent with tainted drywall.

At the news conference on Thursday, officials said the conclusions in that report were premature.

Dean Woodard, the CPSC’s director of defect investigations, said that based on the new report the agency does “not believe there is a connection between the drywall and the tragic deaths.” He called the test results associated with the drywall “unremarkable” and said the CPSC believed they “do not require any follow up.” Only more pesticide-related tests were recommended, he said.

But the testing methods detailed in the new report raised concerns among the experts who reviewed the document for the Herald-Tribune and ProPublica.

“If you want to see what’s wrong with the drywall, you test the drywall. You don’t have to be a rocket scientist to appreciate that when you’re trying to address how much the drywall is off-gassing,” said Michael Shaw, vice president of Interscan Corp. and a member of the ASTM drywall committee. “The idea that they are skating around this and not doing the obvious measurement is very troubling.”

Shaw said then when doing any scientific study, the most direct approach is generally the best.

“If you want to know how much someone weighs, you put him on a scale. You don’t throw him in a swimming pool and try to calculate how much water he displaces,” he said.

Foreman was more blunt: “A company or government official that won’t do a chamber test is one that in my opinion is scared to death of what the results could show.”

Jack McCarthy, president of Environmental Health & Engineering, which conducted the CPSC’s most recent tests, said at the news conference that he saw no reason to conduct chamber tests for out-gassing, because the company had done elemental sulfur tests instead. In those tests, pieces of drywall were examined to measure how much sulfur they contained. McCarthy said his company had also placed strips of copper in the houses for two weeks to see if they would corrode.

But Foreman was skeptical of those methods. Using a controlled setting like a lab chamber—or even a sealed jar—to see whether drywall will corrode copper is more reliable, he said.

“You can’t expect to find any significant amount of corrosion in two weeks unless you’ve have a very, very bad house. It’s just not long enough,” he said. “It’s certainly not what I would hang my hat on to make a definitive pronouncement.”

Two years into the federal investigation of defective drywall, the CPSC has yet to determine precisely what causes some drywall to release sulfur gases. ProPublica and the Sarasota Herald-Tribune have compiled an interactive database of almost 7,000 homeowners who say their houses have been contaminated by defective drywall. Repairing the homes can cost $100,000 or more, because all the electrical wiring and drywall must be removed and then replaced.

Shaw said that at the end of the day, the CPSC and the Army may turn out to be correct in saying that the drywall is not connected to the babies’ deaths. But by not doing the conclusive tests they have likely raised more questions than answers for family members and the wider community.

“There may not be any problem with the drywall, but they didn’t run the obvious test, which to me is suspicious,” he said.