Results Of Indoor Air Quality Testing Of Trailers And Mobile Homes For Formaldehyde In Mississippi And Louisiana

Frequently Asked Questions

  1. Who conducted the testing?
    FEMA and CDC worked together to test formaldehyde levels in trailers and mobile homes.  Professional industrial hygienists under the direction of CDC scientists conducted tests and took measurements.  FEMA staff accompanied the testing team to explain the activities to residents and to discuss with them their housing alternatives.

  2. What did you test for?
    Formaldehyde levels in the air of occupied trailers and mobile homes.

  3. Where did you conduct the tests?
    Tests were conducted in a scientifically chosen random sample of 519 travel trailers, park models, and mobile homes.  Testing occurred in Mississippi and Louisiana in proportion to the presence of each type of unit in each state: 358 travel trailers, and 82 park models and 79 mobile homes.

  4. Why did you only test 519 units?
    Statisticians at the Centers for Disease Control and Prevention (CDC) determined that 519 trailers would provide a statistically valid representation of the temporary housing population on the Gulf Coast and would allow the quickest assessment from which public health experts could characterize formaldehyde levels and make public health recommendations. 

  5. How long did the testing take?
    Testing began on December 21, 2007, and was completed on January 23, 2008.  Test data were assembled into a database, which took about 10 days.  Then CDC analyzed the data to ensure that results were being interpreted correctly.

  6. Why did you conduct the tests?
    FEMA's first priority has been and continues to be the health and safety of our occupants.  CDC shares that concern.  The objective of these tests was to address the concerns of trailer and mobile home residents by testing the units, analyzing the results for patterns and other factors that could impact all residents, and by providing both general and specific information and recommendations so that all occupants can make informed decisions about their housing choices.  The testing will help gauge relative risk and give authorities a better idea of housing placement priorities.

  7. What are the results?
    CDC's preliminary evaluation of a scientifically established random sample of 519 travel trailers and mobile homes tested between Dec. 21, 2007 and Jan. 23, 2008 showed average levels of formaldehyde in all units of about 77 parts per billion (ppb).  Long-term exposure to levels in this range can be linked to an increased risk of cancer, and as levels rise above this range, there can also be a risk of respiratory illness.  This is higher than expected in indoor air, where levels are commonly in the range of 10-20 ppb.  Levels measured ranged from 3 ppb to 590 ppb.

  8. What do the test results mean?
    CDC recommends that FEMA continue to work to relocate all families living in these travel trailers and mobile homes before the warmer weather of summer.  Families that have members who fall into recognized higher risk categories should be relocated sooner.  These include children, elderly persons, persons with chronic health conditions such as asthma or bronchitis, persons exhibiting symptoms (such as difficulty breathing, chronic coughing, chronic runny nose), and women who are pregnant.

    While there are no guidelines for formaldehyde levels in residential housing, various agencies have published levels of concern that vary based on individual circumstances. 
    • Age of people in the unit.  Formaldehyde exposure is a special concern for children and the elderly.  Children might be especially likely to become sensitive to formaldehyde, and the elderly may be less able to tolerate elevated formaldehyde exposures. 
    • Health conditions of people in the unit.  Formaldehyde is irritating to the airways.  People with asthma, bronchitis, or other breathing conditions are especially sensitive to exposures to formaldehyde.  Pregnant women and unborn children also may be especially sensitive.  People with chronic diseases may also be less able to tolerate formaldehyde exposure. 
    • How the unit is used.  Some people are in their units essentially all the time.  Other people are in their units only for shorter periods. 

  9. Do these results apply to other travel trailers or mobile homes?
    Other travel trailers and mobile homes could differ from those evaluated in this study in many ways based on their age, their details of manufacture, and the environments in which they are used. 

  10. Will occupants be notified about the results from their unit?
    Yes.  On Tuesday, February 18, teams of CDC and FEMA representatives will begin the process of visiting residents who participated in the study to deliver letters informing them of the levels of formaldehyde measured in their homes.  CDC and FEMA staff are delivering the letters personally to answer residents' health questions and to discuss their housing alternatives.  In addition, CDC and FEMA are planning several community availability sessions to provide information to other residents who may be concerned about or interested in the findings from the testing.

  11. If a resident not selected for testing as part of the study asks for their unit to be tested, will you test their unit?
    FEMA is in the process of awarding a contract for further testing and will have the capability to provide additional testing of temporary housing units.

  12. What are the accepted guidelines for formaldehyde levels in air?
    There are no federal government guidelines for formaldehyde levels in residential settings for indoor air quality, especially for long-term living conditions.

  13. How do the results of formaldehyde emission levels for indoor air quality in trailers and mobile homes relate to occupational standards of formaldehyde exposure? 
    The results do not relate to occupational standards of formaldehyde exposure.  Occupational standards relate to short duration exposure to high levels, and are covered by an OSHA regulation.   The indoor air quality results relate to chronic exposure in the home setting where no regulation or standard exists.

  14. How do the results relate to the Department of Housing and Urban Development (HUD) standards for manufactured housing construction materials?
    HUD regulates emissions from materials used in construction of manufactured homes, not the resulting level of formaldehyde in the air.   

  15. What is the HUD standard for formaldehyde in mobile homes?
    HUD does not regulate the resulting indoor air quality in mobile homes, they regulate emission controls for certain wood components used in the manufacture of these homes.  All materials used in the manufacture of mobile homes must comply with Title 24 of the Code of Federal Regulations sections 3280.308-309.  HUD standards for manufactured housing do not set levels for ambient air - meaning the air that rests inside the domicile at any given time.  Instead, standards restrict the materials that may be used in manufactured home construction in terms of their formaldehyde emitting qualities.  Congress has not given HUD the legal ability (authority) to test ambient air for the existence of formaldehyde during the production process.  HUD instead regulates the levels found in products used in the manufacturing process.

  16. Why are mobile homes included with trailers in this process?
    Manufactured housing (often called "mobile homes") is included as part of the random sample because FEMA has provided a large number of this type of housing in the Gulf Coast Region.  While provided as temporary housing, mobile homes are also designed for long-term habitation.  Millions of Americans live in manufactured housing across the nation.  The results of these tests cannot be used to made determinations about those dwellings. 

  17. Were the tests scheduled to coincide with the cooler weather and less humid conditions of the winter months?
    No.  However, we recognize that cool weather testing cannot be generalized to summer conditions.  Formaldehyde levels are typically higher in warmer weather. Accordingly, we believe that residents experienced higher levels of exposure when their trailers and mobile homes were newer and during summer months.  CDC has recommended that FEMA work to relocate families before weather warms again. 

  18. If occupants have health concerns, what are their options?
    CDC has recommended that FEMA relocate all families living in trailers and mobile homes before the weather warms again.  FEMA's goal is to move all occupants out of temporary housing as rapidly as possible.  Occupants who have health concerns associated with their units have been offered the option to move into a hotel or motel until more permanent housing is located.  Occupants can contact FEMA's formaldehyde hotline with questions or concerns: (866) 562-2381 or TTY 1 (800) 462-7585.

  19. Why does FEMA continue to allow occupants to live in these units if they may be hazardous to occupants' health?
    FEMA has always made the health and well-being of families in FEMA-provided housing our top priority.  FEMA has repeatedly emphasized our desire to move residents from temporary housing into alternative or more permanent housing solutions. 

    FEMA is actively working with all occupants living in trailers and mobile homes to move them into alternative long-term housing as rapidly as possible.  FEMA will move any resident into a hotel or motel immediately and is working with all residents to provide them with a housing alternative.  Every occupant who has expressed health concerns to the FEMA hotline has been offered a housing alternative, and FEMA is working with each of them to find a permanent housing solution that meets their family needs.  FEMA has also ceased the sale and deployment of travel trailers while awaiting the result of the studies.

  20. How many trailers and mobile homes in the Gulf Coast are currently occupied?
    As of February 1, 2008, there were approximately 38,297 households located in trailers and mobile homes. Since July 1, 2007, 27,796 households have moved out of trailers and mobile homes. On average, FEMA has been moving 810 households out of trailers and mobile homes weekly across the Gulf Coast.

  21. How many people have been identified as having heath concerns because of formaldehyde?
    On July 21, 2007 FEMA set up a Formaldehyde Call Center for occupants living in trailers and mobile homes who have questions or concerns about formaldehyde.  Not all of these calls represent complaints or requests for relief; many are calls simply to request information.  As of February 1, 2008, the total numbers of occupants that have contacted the FEMA Formaldehyde Call Center and requested alternative housing are as follows: 

    State of Louisiana: 4,178
    State of Mississippi: 1,385
    State of Alabama:                  44
    State of Texas:  1,474
    Total:   7,081

    All 7,081 households have been offered an immediate move to a hotel or motel.  To date, 884 have accepted this option, while 2,510 have moved into alternative long-term housing options, 578 have refused all options, and the remaining have been provided with a variety of alternatives, are considering their options, and are being actively engaged by FEMA staff to find them an alternative housing solution.

  22. Why is there a delay in providing alternative housing for those who request it?
    Housing stock is still limited.  However, FEMA is working with occupants and providing options.  To take advantage of alternatives, occupants must make their decisions based on what best fits their needs, and based on the resources available to them.  Occupants may request and receive rental assistance in order to move into an apartment or other rented living alternative.  However, in order to be eligible to receive rental assistance, occupants must apply for and pass a credit check or a background check at the request of the landlord.  In addition, because landlords receive payment directly from the federal government, landlords must first go through a registration process of their own.  All parties must agree on a move-in date before FEMA can authorize and provide rental assistance.  Occupants should contact FEMA if they are experiencing any unexplained delays.

  23. Why did FEMA take so long to begin this testing?
    Testing of this scale and, importantly, developing an understanding of what the results might mean, took several months to arrange.

    The decision to temporarily suspend the sampling scheduled for early November 2007 was made because FEMA determined that in order to be able to provide guidance to occupants about their health and housing options, we needed public health guidance or approved "action levels."  There exists a tremendous range of "levels of concern" across international, national and professional organizations, so a number of experts were consulted to develop an appropriate strategy for protecting occupants' health without introducing new risks.

    FEMA worked closely with CDC and the public health community to develop a consensus approach to developing public health guidance, and completed that in late November, 2007.  The contract was awarded two weeks after that and testing began within ten days, on December 21.

  24. Will FEMA require relocation for those in trailers with elevated levels of formaldehyde?
    The final determination of mandatory relocation of any occupants will be made on a case by case basis.

  25. Have the levels of those who have called to complain about potential exposure through the hotline been tested?  Why/why not?
    As of February 1, 2008, 1,784 households have called the hotline to request a test.

    FEMA is in the process of awarding a contract for further testing therefore FEMA will have the capability to provide additional testing of temporary housing units.

  26. What Is FEMA going to do with the results?
    FEMA will continue to actively work with all occupants living in trailers and mobile homes to move them into alternative long-term housing before the summer.  FEMA will move any resident into a hotel or motel immediately upon request and is working with all residents to provide them with a housing alternative.

    FEMA will appoint a Senior Executive Service employee to lead a multi-jurisdictional task force comprised of key Federal and State agency partners who will commit high-level, experienced personnel to assist FEMA in this aggressive relocation effort.

Last Modified: Thursday, 14-Feb-2008 13:21:13 EST