ARCHIVED - Results of formaldehyde testing in homes with RetroFoam

Health Canada provided homeowners with the opportunity to test the indoor air in their homes for formaldehyde in both winter and summer of 2009. Overall, 790 homes with RetroFoam were tested at least once. Formaldehyde levels were very different from house to house, and were generally higher in the summer on hot days, when windows were closed and the air conditioning was turned on.


  • Just over one-third of homes (37%) had formaldehyde levels, in both summer and winter tests, that were below Health Canada's residential indoor air quality guideline. People in these homes should not experience any symptoms.
  • For the 63% of homes with a formaldehyde test result above 50 µg/m3, sensitive people, such as a child with asthma, may experience coughing, wheezing or asthma symptoms requiring treatment.
  • In the 12% of homes with a test result above 123 µg/m3, people who are sensitive to formaldehyde may also experience irritation of the eyes, nose or throat.
  • While formaldehyde is recognized as a human carcinogen, the risk of cancer at levels that can be found in homes - including the levels found during this testing - is essentially zero.
Figure 1. Results of formaldehyde testing in homes with RetroFoam; showing the percentage of homes with a maximum formaldehyde value (a) less than 50 µg/m3, (b) between 50 and 123 µg/m3 or (c) greater than 123 µg/m3
Figure 1. Results of formaldehyde testing in homes with RetroFoam; showing the percentage of homes with a maximum formaldehyde value (a) less than 50 µg/m
, (b) between 50 and 123 µg/m
or (c) greater than 123 µg/m

All homes in Canada contain some formaldehyde. Sources of formaldehyde include tobacco smoke, wood burning stoves, and construction materials; therefore, even homes without RetroFoam may exceed Health Canada's recommended levels.

Health Canada's residential indoor air quality guideline of 50 µg/m3 is set to protect the most sensitive individuals, in this case, children with asthma. Being above the guideline does not necessarily mean that residents will experience any health symptoms. Sensitive individuals may, however, experience more breathing problems than they would if formaldehyde levels were lower.

Health risks would have been highest immediately following installation of RetroFoam and will decrease over time. Laboratory testing shows that the amount of formaldehyde released from RetroFoam will decrease over time. It could, however, take months or even years after installation for emissions to stop. This is consistent with previous studies of UFFI undertaken in the 1980s. Homes tested a few years after the installation of UFFI had similar levels of formaldehyde to homes without UFFI. It is possible that if the foam gets wet it may start to release more formaldehyde.

Homeowners who are concerned about the potential health risks or who are experiencing any respiratory symptoms should talk to their physician. They may also take steps to lower the formaldehyde level in their home by removing sources of formaldehyde or by increasing ventilation. Decreasing the level of formaldehyde in a house will lower the risk of respiratory problems for its occupants.

For information on the health risks of formaldehyde and how to reduce levels please visit

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