Updated

Lawyers for a group of hurricane victims living in government-issued trailers are asking a federal judge to order the Federal Emergency Management Agency to test the housing units for hazardous fumes.

Earlier this month, FEMA postponed plans to test the air quality in its travel trailers for levels of formaldehyde. The chemical, a common preservative found in materials used to build manufactured homes, can cause respiratory illnesses and is classified as a carcinogen.

FEMA says it needs more time to prepare before scientists from the U.S. Centers for Disease Control and Prevention in Atlanta begin the formaldehyde tests, which were scheduled to start in Mississippi on Nov. 2.

However, attorneys for trailer occupants in Louisiana claim FEMA's delay in testing the trailers is jeopardizing the health of thousands of Gulf Coast residents displaced by hurricanes Katrina and Rita in 2005.

In court papers filed Friday, the trailer occupants' lawyers asked a federal judge in New Orleans to issue a preliminary injunction that would compel FEMA to begin the tests. The injunction also calls for FEMA to immediately comply with any trailer occupant's request to move out of a unit and into alternative housing.

U.S. District Judge Kurt Englehardt did not immediately rule on their requests.

"Without this Court's intervention," the storm victims' attorneys wrote, "FEMA will continue to delay and this national public health emergency will continue unabated."

FEMA spokesman Michael Widomski, who would not comment on the litigation, said a date to start the tests has not been set. "We're continuing to work with the CDC," he added.

Roy Rodney, Jr., a New Orleans-based attorney who filed the motion for an injunction, said the formaldehyde tests are a "matter of critical public health."

"It's important to understand what the level of exposure is, particularly in regard to children," he said. "Children are the most at risk, more so than adults."

In Louisiana and Mississippi, more than 48,000 FEMA trailers were occupied this month by victims of the 2005 hurricanes. Reacting to residents' health concerns, FEMA has moved hundreds of families in both states out of trailers and into apartments, hotel rooms or other temporary housing.

FEMA also has temporarily suspended the sale of its used trailers and says the units won't be used to shelter victims of future disasters until the safety concerns are resolved.

Hundreds of Gulf Coast residents are suing trailer manufacturers for allegedly providing FEMA with poorly constructed units contaminated by formaldehyde. Several of those federal lawsuits in Louisiana were consolidated on Oct. 24 and transferred to Englehardt, who scheduled a Jan. 18 initial hearing on the litigation.